* Re: [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2)
2025-12-22 4:08 [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2) syzbot
@ 2026-01-07 2:04 ` Chao Yu
2026-01-07 2:19 ` syzbot
2026-01-07 6:44 ` Forwarded: " syzbot
` (3 subsequent siblings)
4 siblings, 1 reply; 11+ messages in thread
From: Chao Yu @ 2026-01-07 2:04 UTC (permalink / raw)
To: syzbot, jaegeuk, linux-f2fs-devel, linux-kernel, syzkaller-bugs; +Cc: chao
#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git bugfix/syzbot
On 12/22/2025 12:08 PM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 765b233a9b94 Merge tag 'i2c-for-6.19-rc2' of git://git.ker..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=17a56b1a580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=513255d80ab78f2b
> dashboard link: https://syzkaller.appspot.com/bug?extid=b4444e3c972a7a124187
> compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=174b0b58580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=162f8b1a580000
>
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-765b233a.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/f8288fd6c7cc/vmlinux-765b233a.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/2a2ef1044b19/bzImage-765b233a.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/333719a5e15d/mount_1.gz
> fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=17faddb4580000)
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+b4444e3c972a7a124187@syzkaller.appspotmail.com
>
> ==================================================================
> BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline]
> BUG: KASAN: slab-use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
> BUG: KASAN: slab-use-after-free in get_pages fs/f2fs/f2fs.h:2718 [inline]
> BUG: KASAN: slab-use-after-free in f2fs_write_end_io+0x9b9/0xb60 fs/f2fs/data.c:364
> Read of size 4 at addr ffff88804357d170 by task kworker/u4:4/45
>
> CPU: 0 UID: 0 PID: 45 Comm: kworker/u4:4 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
> Workqueue: loop0 loop_workfn
> Call Trace:
> <TASK>
> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
> print_address_description mm/kasan/report.c:378 [inline]
> print_report+0xca/0x240 mm/kasan/report.c:482
> kasan_report+0x118/0x150 mm/kasan/report.c:595
> check_region_inline mm/kasan/generic.c:-1 [inline]
> kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200
> instrument_atomic_read include/linux/instrumented.h:68 [inline]
> atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
> get_pages fs/f2fs/f2fs.h:2718 [inline]
> f2fs_write_end_io+0x9b9/0xb60 fs/f2fs/data.c:364
> blk_update_request+0x57e/0xe60 block/blk-mq.c:1007
> blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1169
> lo_rw_aio_complete drivers/block/loop.c:337 [inline]
> lo_rw_aio+0xcd1/0xef0 drivers/block/loop.c:410
> do_req_filebacked drivers/block/loop.c:-1 [inline]
> loop_handle_cmd drivers/block/loop.c:1926 [inline]
> loop_process_work+0x8fe/0x10b0 drivers/block/loop.c:1961
> process_one_work kernel/workqueue.c:3257 [inline]
> process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
> worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
> kthread+0x711/0x8a0 kernel/kthread.c:463
> ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
> </TASK>
>
> Allocated by task 5484:
> kasan_save_stack mm/kasan/common.c:56 [inline]
> kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
> poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
> __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
> kasan_kmalloc include/linux/kasan.h:262 [inline]
> __kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5776
> kmalloc_noprof include/linux/slab.h:957 [inline]
> kzalloc_noprof include/linux/slab.h:1094 [inline]
> f2fs_fill_super+0x8c/0x6ec0 fs/f2fs/super.c:4895
> get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
> vfs_get_tree+0x92/0x2a0 fs/super.c:1751
> fc_mount fs/namespace.c:1199 [inline]
> do_new_mount_fc fs/namespace.c:3636 [inline]
> do_new_mount+0x302/0xa10 fs/namespace.c:3712
> do_mount fs/namespace.c:4035 [inline]
> __do_sys_mount fs/namespace.c:4224 [inline]
> __se_sys_mount+0x313/0x410 fs/namespace.c:4201
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Freed by task 5484:
> kasan_save_stack mm/kasan/common.c:56 [inline]
> kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
> kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
> poison_slab_object mm/kasan/common.c:252 [inline]
> __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
> kasan_slab_free include/linux/kasan.h:234 [inline]
> slab_free_hook mm/slub.c:2540 [inline]
> slab_free mm/slub.c:6670 [inline]
> kfree+0x1c0/0x660 mm/slub.c:6878
> kill_f2fs_super+0x5b6/0x6c0 fs/f2fs/super.c:5458
> deactivate_locked_super+0xbc/0x130 fs/super.c:474
> cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
> task_work_run+0x1d4/0x260 kernel/task_work.c:233
> exit_task_work include/linux/task_work.h:40 [inline]
> do_exit+0x694/0x22f0 kernel/exit.c:971
> do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
> __do_sys_exit_group kernel/exit.c:1123 [inline]
> __se_sys_exit_group kernel/exit.c:1121 [inline]
> __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
> __pfx_syscall_get_nr+0x0/0x10 arch/x86/include/generated/asm/syscalls_64.h:232
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Last potentially related work creation:
> kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
> kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
> insert_work+0x3d/0x330 kernel/workqueue.c:2180
> __queue_work+0xcd0/0xf90 kernel/workqueue.c:2335
> queue_work_on+0x106/0x1c0 kernel/workqueue.c:2386
> queue_work include/linux/workqueue.h:669 [inline]
> schedule_work include/linux/workqueue.h:730 [inline]
> f2fs_handle_critical_error+0x255/0x540 fs/f2fs/super.c:4624
> f2fs_write_end_io+0x886/0xb60 fs/f2fs/data.c:351
> __submit_merged_bio+0x256/0x660 fs/f2fs/data.c:540
> __f2fs_submit_merged_write fs/f2fs/data.c:635 [inline]
> __submit_merged_write_cond+0x471/0x530 fs/f2fs/data.c:657
> f2fs_sync_node_pages+0x1479/0x15e0 fs/f2fs/node.c:2166
> block_operations fs/f2fs/checkpoint.c:1276 [inline]
> f2fs_write_checkpoint+0xdd5/0x2430 fs/f2fs/checkpoint.c:1678
> kill_f2fs_super+0x2d2/0x6c0 fs/f2fs/super.c:5448
> deactivate_locked_super+0xbc/0x130 fs/super.c:474
> cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
> task_work_run+0x1d4/0x260 kernel/task_work.c:233
> exit_task_work include/linux/task_work.h:40 [inline]
> do_exit+0x694/0x22f0 kernel/exit.c:971
> do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
> __do_sys_exit_group kernel/exit.c:1123 [inline]
> __se_sys_exit_group kernel/exit.c:1121 [inline]
> __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
> __pfx_syscall_get_nr+0x0/0x10 arch/x86/include/generated/asm/syscalls_64.h:232
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Second to last potentially related work creation:
> kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
> kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
> insert_work+0x3d/0x330 kernel/workqueue.c:2180
> __queue_work+0xcd0/0xf90 kernel/workqueue.c:2335
> queue_work_on+0x106/0x1c0 kernel/workqueue.c:2386
> sanity_check_node_footer fs/f2fs/node.c:1536 [inline]
> __get_node_folio+0xcaf/0x14f0 fs/f2fs/node.c:1581
> do_read_inode fs/f2fs/inode.c:425 [inline]
> f2fs_iget+0x77c/0x5640 fs/f2fs/inode.c:596
> f2fs_nfs_get_inode+0x76/0x110 fs/f2fs/super.c:3723
> generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1498
> exportfs_decode_fh_raw+0x178/0x6e0 fs/exportfs/expfs.c:456
> do_handle_to_path+0xa4/0x1a0 fs/fhandle.c:276
> handle_to_path fs/fhandle.c:400 [inline]
> do_handle_open+0x6a1/0x930 fs/fhandle.c:424
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> The buggy address belongs to the object at ffff88804357c000
> which belongs to the cache kmalloc-8k of size 8192
> The buggy address is located 4464 bytes inside of
> freed 8192-byte region [ffff88804357c000, ffff88804357e000)
>
> The buggy address belongs to the physical page:
> page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x43578
> head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
> flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
> page_type: f5(slab)
> raw: 04fff00000000040 ffff88801a442280 ffffea000046b000 0000000000000002
> raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
> head: 04fff00000000040 ffff88801a442280 ffffea000046b000 0000000000000002
> head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
> head: 04fff00000000003 ffffea00010d5e01 00000000ffffffff 00000000ffffffff
> head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
> page dumped because: kasan: bad access detected
> page_owner tracks the page as allocated
> page last allocated via order 3, migratetype Unmovable, gfp_mask 0x528c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP), pid 5411, tgid 5411 (syz-executor), ts 97414573985, free_ts 95403368329
> set_page_owner include/linux/page_owner.h:32 [inline]
> post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
> prep_new_page mm/page_alloc.c:1854 [inline]
> get_page_from_freelist+0x24e0/0x2580 mm/page_alloc.c:3915
> __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
> alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
> alloc_slab_page mm/slub.c:3075 [inline]
> allocate_slab+0x86/0x3b0 mm/slub.c:3248
> new_slab mm/slub.c:3302 [inline]
> ___slab_alloc+0xe53/0x1820 mm/slub.c:4656
> __slab_alloc+0x65/0x100 mm/slub.c:4779
> __slab_alloc_node mm/slub.c:4855 [inline]
> slab_alloc_node mm/slub.c:5251 [inline]
> __do_kmalloc_node mm/slub.c:5656 [inline]
> __kvmalloc_node_noprof+0x6b6/0x920 mm/slub.c:7136
> kvmalloc_array_node_noprof include/linux/slab.h:1122 [inline]
> __ptr_ring_init_queue_alloc_noprof include/linux/ptr_ring.h:481 [inline]
> ptr_ring_init_noprof include/linux/ptr_ring.h:499 [inline]
> wg_packet_queue_init+0xbc/0x320 drivers/net/wireguard/queueing.c:32
> wg_newlink+0x2f6/0x670 drivers/net/wireguard/device.c:352
> rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3840
> __rtnl_newlink net/core/rtnetlink.c:3957 [inline]
> rtnl_newlink+0x16e7/0x1c90 net/core/rtnetlink.c:4072
> rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
> netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
> netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
> netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
> netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
> page last free pid 4363 tgid 4363 stack trace:
> reset_page_owner include/linux/page_owner.h:25 [inline]
> free_pages_prepare mm/page_alloc.c:1395 [inline]
> __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
> unix_net_exit+0x6b/0xb0 net/unix/af_unix.c:3837
> ops_exit_list net/core/net_namespace.c:199 [inline]
> ops_undo_list+0x49a/0x990 net/core/net_namespace.c:252
> cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696
> process_one_work kernel/workqueue.c:3257 [inline]
> process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
> worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
> kthread+0x711/0x8a0 kernel/kthread.c:463
> ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
>
> Memory state around the buggy address:
> ffff88804357d000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88804357d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ffff88804357d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff88804357d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88804357d200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2)
2026-01-07 2:04 ` Chao Yu
@ 2026-01-07 2:19 ` syzbot
0 siblings, 0 replies; 11+ messages in thread
From: syzbot @ 2026-01-07 2:19 UTC (permalink / raw)
To: chao, jaegeuk, linux-f2fs-devel, linux-kernel, syzkaller-bugs
Hello,
syzbot tried to test the proposed patch but the build/boot failed:
c 0x1003 length: 249 > 9
[ 99.252780][ T4680] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[ 99.258304][ T4680] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[ 99.262003][ T4680] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[ 99.904250][ T947] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 99.908039][ T947] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 99.960090][ T1131] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 99.963625][ T1131] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 101.111055][ T5380] chnl_net:caif_netlink_parms(): no params data found
[ 101.277872][ T5380] bridge0: port 1(bridge_slave_0) entered blocking state
[ 101.286086][ T5380] bridge0: port 1(bridge_slave_0) entered disabled state
[ 101.289331][ T5380] bridge_slave_0: entered allmulticast mode
[ 101.304573][ T5380] bridge_slave_0: entered promiscuous mode
[ 101.311175][ T5380] bridge0: port 2(bridge_slave_1) entered blocking state
[ 101.314400][ T5380] bridge0: port 2(bridge_slave_1) entered disabled state
[ 101.318351][ T5380] bridge_slave_1: entered allmulticast mode
[ 101.322134][ T5380] bridge_slave_1: entered promiscuous mode
[ 101.348427][ T5380] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 101.357433][ T5380] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 101.383478][ T5380] team0: Port device team_slave_0 added
[ 101.388135][ T5380] team0: Port device team_slave_1 added
[ 101.411977][ T5380] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 101.415073][ T5380] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 101.427067][ T5380] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 101.433759][ T5380] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 101.437187][ T5380] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 101.448054][ T5380] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 101.483243][ T5380] hsr_slave_0: entered promiscuous mode
[ 101.486999][ T5380] hsr_slave_1: entered promiscuous mode
[ 101.640469][ T5380] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 101.650511][ T5380] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 101.657246][ T5380] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 101.663682][ T5380] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 101.742774][ T5380] 8021q: adding VLAN 0 to HW filter on device bond0
[ 101.761501][ T5380] 8021q: adding VLAN 0 to HW filter on device team0
[ 101.770624][ T947] bridge0: port 1(bridge_slave_0) entered blocking state
[ 101.773903][ T947] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 101.786737][ T1131] bridge0: port 2(bridge_slave_1) entered blocking state
[ 101.789882][ T1131] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 102.002757][ T5380] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 102.041139][ T5380] veth0_vlan: entered promiscuous mode
[ 102.050273][ T5380] veth1_vlan: entered promiscuous mode
[ 102.080200][ T5380] veth0_macvtap: entered promiscuous mode
[ 102.087176][ T5380] veth1_macvtap: entered promiscuous mode
[ 102.108084][ T5380] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 102.119233][ T5380] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 102.129583][ T947] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[ 102.141577][ T947] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[ 102.145405][ T947] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[ 102.160213][ T4047] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[ 102.423332][ T3019] netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 102.589933][ T3019] netdevsim netdevsim0 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 102.698091][ T3019] netdevsim netdevsim0 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 102.788477][ T3019] netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 105.309210][ T3019] bridge_slave_1: left allmulticast mode
[ 105.311909][ T3019] bridge_slave_1: left promiscuous mode
[ 105.331282][ T3019] bridge0: port 2(bridge_slave_1) entered disabled state
[ 105.387138][ T3019] bridge_slave_0: left allmulticast mode
[ 105.389688][ T3019] bridge_slave_0: left promiscuous mode
[ 105.392386][ T3019] bridge0: port 1(bridge_slave_0) entered disabled state
[ 106.096537][ T3019] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
[ 106.103033][ T3019] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
[ 106.117388][ T3019] bond0 (unregistering): Released all slaves
[ 106.229126][ T3019] hsr_slave_0: left promiscuous mode
[ 106.246123][ T3019] hsr_slave_1: left promiscuous mode
[ 106.258491][ T3019] batman_adv: batadv0: Interface deactivated: batadv_slave_0
[ 106.261745][ T3019] batman_adv: batadv0: Removing interface: batadv_slave_0
[ 106.286794][ T3019] batman_adv: batadv0: Interface deactivated: batadv_slave_1
[ 106.290111][ T3019] batman_adv: batadv0: Removing interface: batadv_slave_1
[ 106.325813][ T3019] veth1_macvtap: left promiscuous mode
[ 106.329044][ T3019] veth0_macvtap: left promiscuous mode
[ 106.331694][ T3019] veth1_vlan: left promiscuous mode
[ 106.334122][ T3019] veth0_vlan: left promiscuous mode
[ 106.797480][ T3019] team0 (unregistering): Port device team_slave_1 removed
[ 106.821140][ T3019] team0 (unregistering): Port device team_slave_0 removed
2026/01/07 02:18:07 executed programs: 0
[ 108.259947][ T46] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[ 108.264618][ T46] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[ 108.270695][ T46] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[ 108.274422][ T46] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[ 108.278195][ T46] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[ 108.730010][ T5451] chnl_net:caif_netlink_parms(): no params data found
[ 108.907477][ T5451] bridge0: port 1(bridge_slave_0) entered blocking state
[ 108.910655][ T5451] bridge0: port 1(bridge_slave_0) entered disabled state
[ 108.913831][ T5451] bridge_slave_0: entered allmulticast mode
[ 108.929157][ T5451] bridge_slave_0: entered promiscuous mode
[ 108.939210][ T5451] bridge0: port 2(bridge_slave_1) entered blocking state
[ 108.942482][ T5451] bridge0: port 2(bridge_slave_1) entered disabled state
[ 108.950846][ T5451] bridge_slave_1: entered allmulticast mode
[ 108.965783][ T5451] bridge_slave_1: entered promiscuous mode
[ 109.018144][ T5451] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 109.026049][ T5451] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 109.073929][ T5451] team0: Port device team_slave_0 added
[ 109.085217][ T5451] team0: Port device team_slave_1 added
[ 109.128253][ T5451] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 109.131303][ T5451] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 109.156217][ T5451] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 109.177176][ T5451] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 109.180214][ T5451] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 109.208335][ T5451] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 109.278165][ T5451] hsr_slave_0: entered promiscuous mode
[ 109.286205][ T5451] hsr_slave_1: entered promiscuous mode
[ 109.779620][ T5451] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 109.800234][ T5451] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 109.807679][ T5451] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 109.829275][ T5451] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 109.967755][ T5451] 8021q: adding VLAN 0 to HW filter on device bond0
[ 109.993637][ T5451] 8021q: adding VLAN 0 to HW filter on device team0
[ 110.013449][ T947] bridge0: port 1(bridge_slave_0) entered blocking state
[ 110.016837][ T947] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 110.041939][ T947] bridge0: port 2(bridge_slave_1) entered blocking state
[ 110.045001][ T947] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 110.113140][ T5451] hsr0: Slave A (hsr_slave_0) is not up; please bring it up to get a fully working HSR network
[ 110.126403][ T5451] hsr0: Slave B (hsr_slave_1) is not up; please bring it up to get a fully working HSR network
[ 110.306727][ T46] Bluetooth: hci0: command tx timeout
[ 110.407891][ T5451] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 110.474914][ T5451] veth0_vlan: entered promiscuous mode
[ 110.501129][ T5451] veth1_vlan: entered promiscuous mode
[ 110.548766][ T5451] veth0_macvtap: entered promiscuous mode
[ 110.566415][ T5451] veth1_macvtap: entered promiscuous mode
[ 110.594368][ T5451] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 110.627391][ T5451] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 110.639617][ T947] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[ 110.643516][ T947] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[ 110.667089][ T947] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[ 110.702519][ T947] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[ 110.791338][ T947] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 110.795044][ T947] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 110.848266][ T947] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 110.851713][ T947] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
SYZFAIL: failed to recv rpc
fd=3 want=4 recv=0 n=0 (errno 9: Bad file descriptor)
[ 112.188996][ T1131] netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 113.352275][ T1131] netdevsim netdevsim0 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 113.627013][ T1131] netdevsim netdevsim0 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 113.684954][ T1131] netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 113.807220][ T1131] bridge_slave_1: left allmulticast mode
[ 113.809850][ T1131] bridge_slave_1: left promiscuous mode
[ 113.812539][ T1131] bridge0: port 2(bridge_slave_1) entered disabled state
[ 113.832063][ T1131] bridge_slave_0: left allmulticast mode
[ 113.834590][ T1131] bridge_slave_0: left promiscuous mode
[ 113.837572][ T1131] bridge0: port 1(bridge_slave_0) entered disabled state
[ 114.221189][ T1131] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
[ 114.227289][ T1131] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
[ 114.232468][ T1131] bond0 (unregistering): Released all slaves
[ 114.487951][ T1131] hsr_slave_0: left promiscuous mode
[ 114.490767][ T1131] hsr_slave_1: left promiscuous mode
[ 114.498999][ T1131] batman_adv: batadv0: Interface deactivated: batadv_slave_0
[ 114.502267][ T1131] batman_adv: batadv0: Removing interface: batadv_slave_0
[ 114.517714][ T1131] batman_adv: batadv0: Interface deactivated: batadv_slave_1
[ 114.521062][ T1131] batman_adv: batadv0: Removing interface: batadv_slave_1
[ 114.549206][ T1131] veth1_macvtap: left promiscuous mode
[ 114.551802][ T1131] veth0_macvtap: left promiscuous mode
[ 114.554336][ T1131] veth1_vlan: left promiscuous mode
[ 114.567501][ T1131] veth0_vlan: left promiscuous mode
[ 114.940636][ T1131] team0 (unregistering): Port device team_slave_1 removed
[ 114.967019][ T1131] team0 (unregistering): Port device team_slave_0 removed
syzkaller build log:
go env (err=<nil>)
AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE='auto'
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/syzkaller/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/syzkaller/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build1445029477=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOMODCACHE='/syzkaller/jobs/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs/linux/gopath'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/syzkaller/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.24.4'
GOWORK=''
PKG_CONFIG='pkg-config'
git status (err=<nil>)
HEAD detached at d1b870e1003b
nothing to commit, working tree clean
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
go list -f '{{.Stale}}' -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d1b870e1003b52891d2196c1e2ee42fe905010ba -X github.com/google/syzkaller/prog.gitRevisionDate=20251128-125159" ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d1b870e1003b52891d2196c1e2ee42fe905010ba -X github.com/google/syzkaller/prog.gitRevisionDate=20251128-125159" ./sys/syz-sysgen
make .descriptions
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
bin/syz-sysgen
touch .descriptions
GOOS=linux GOARCH=amd64 go build -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d1b870e1003b52891d2196c1e2ee42fe905010ba -X github.com/google/syzkaller/prog.gitRevisionDate=20251128-125159" -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
mkdir -p ./bin/linux_amd64
g++ -o ./bin/linux_amd64/syz-executor executor/executor.cc \
-m64 -O2 -pthread -Wall -Werror -Wparentheses -Wunused-const-variable -Wframe-larger-than=16384 -Wno-stringop-overflow -Wno-array-bounds -Wno-format-overflow -Wno-unused-but-set-variable -Wno-unused-command-line-argument -static-pie -std=c++17 -I. -Iexecutor/_include -DGOOS_linux=1 -DGOARCH_amd64=1 \
-DHOSTGOOS_linux=1 -DGIT_REVISION=\"d1b870e1003b52891d2196c1e2ee42fe905010ba\"
/usr/bin/ld: /tmp/cc4kC0pD.o: in function `Connection::Connect(char const*, char const*)':
executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x104): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
./tools/check-syzos.sh 2>/dev/null
Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=12df7e9a580000
Tested on:
commit: af98ee9d f2fs: fix use-after-free in f2fs_write_end_io
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git bugfix/syzbot
kernel config: https://syzkaller.appspot.com/x/.config?x=513255d80ab78f2b
dashboard link: https://syzkaller.appspot.com/bug?extid=b4444e3c972a7a124187
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Note: no patches were applied.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Forwarded: Re: [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2)
2025-12-22 4:08 [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2) syzbot
2026-01-07 2:04 ` Chao Yu
@ 2026-01-07 6:44 ` syzbot
2026-01-07 8:49 ` syzbot
` (2 subsequent siblings)
4 siblings, 0 replies; 11+ messages in thread
From: syzbot @ 2026-01-07 6:44 UTC (permalink / raw)
To: linux-kernel
For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.
***
Subject: Re: [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2)
Author: chao@kernel.org
#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git bugfix/syzbot
On 12/22/2025 12:08 PM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 765b233a9b94 Merge tag 'i2c-for-6.19-rc2' of git://git.ker..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=17a56b1a580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=513255d80ab78f2b
> dashboard link: https://syzkaller.appspot.com/bug?extid=b4444e3c972a7a124187
> compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=174b0b58580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=162f8b1a580000
>
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-765b233a.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/f8288fd6c7cc/vmlinux-765b233a.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/2a2ef1044b19/bzImage-765b233a.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/333719a5e15d/mount_1.gz
> fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=17faddb4580000)
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+b4444e3c972a7a124187@syzkaller.appspotmail.com
>
> ==================================================================
> BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline]
> BUG: KASAN: slab-use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
> BUG: KASAN: slab-use-after-free in get_pages fs/f2fs/f2fs.h:2718 [inline]
> BUG: KASAN: slab-use-after-free in f2fs_write_end_io+0x9b9/0xb60 fs/f2fs/data.c:364
> Read of size 4 at addr ffff88804357d170 by task kworker/u4:4/45
>
> CPU: 0 UID: 0 PID: 45 Comm: kworker/u4:4 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
> Workqueue: loop0 loop_workfn
> Call Trace:
> <TASK>
> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
> print_address_description mm/kasan/report.c:378 [inline]
> print_report+0xca/0x240 mm/kasan/report.c:482
> kasan_report+0x118/0x150 mm/kasan/report.c:595
> check_region_inline mm/kasan/generic.c:-1 [inline]
> kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200
> instrument_atomic_read include/linux/instrumented.h:68 [inline]
> atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
> get_pages fs/f2fs/f2fs.h:2718 [inline]
> f2fs_write_end_io+0x9b9/0xb60 fs/f2fs/data.c:364
> blk_update_request+0x57e/0xe60 block/blk-mq.c:1007
> blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1169
> lo_rw_aio_complete drivers/block/loop.c:337 [inline]
> lo_rw_aio+0xcd1/0xef0 drivers/block/loop.c:410
> do_req_filebacked drivers/block/loop.c:-1 [inline]
> loop_handle_cmd drivers/block/loop.c:1926 [inline]
> loop_process_work+0x8fe/0x10b0 drivers/block/loop.c:1961
> process_one_work kernel/workqueue.c:3257 [inline]
> process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
> worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
> kthread+0x711/0x8a0 kernel/kthread.c:463
> ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
> </TASK>
>
> Allocated by task 5484:
> kasan_save_stack mm/kasan/common.c:56 [inline]
> kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
> poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
> __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
> kasan_kmalloc include/linux/kasan.h:262 [inline]
> __kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5776
> kmalloc_noprof include/linux/slab.h:957 [inline]
> kzalloc_noprof include/linux/slab.h:1094 [inline]
> f2fs_fill_super+0x8c/0x6ec0 fs/f2fs/super.c:4895
> get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
> vfs_get_tree+0x92/0x2a0 fs/super.c:1751
> fc_mount fs/namespace.c:1199 [inline]
> do_new_mount_fc fs/namespace.c:3636 [inline]
> do_new_mount+0x302/0xa10 fs/namespace.c:3712
> do_mount fs/namespace.c:4035 [inline]
> __do_sys_mount fs/namespace.c:4224 [inline]
> __se_sys_mount+0x313/0x410 fs/namespace.c:4201
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Freed by task 5484:
> kasan_save_stack mm/kasan/common.c:56 [inline]
> kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
> kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
> poison_slab_object mm/kasan/common.c:252 [inline]
> __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
> kasan_slab_free include/linux/kasan.h:234 [inline]
> slab_free_hook mm/slub.c:2540 [inline]
> slab_free mm/slub.c:6670 [inline]
> kfree+0x1c0/0x660 mm/slub.c:6878
> kill_f2fs_super+0x5b6/0x6c0 fs/f2fs/super.c:5458
> deactivate_locked_super+0xbc/0x130 fs/super.c:474
> cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
> task_work_run+0x1d4/0x260 kernel/task_work.c:233
> exit_task_work include/linux/task_work.h:40 [inline]
> do_exit+0x694/0x22f0 kernel/exit.c:971
> do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
> __do_sys_exit_group kernel/exit.c:1123 [inline]
> __se_sys_exit_group kernel/exit.c:1121 [inline]
> __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
> __pfx_syscall_get_nr+0x0/0x10 arch/x86/include/generated/asm/syscalls_64.h:232
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Last potentially related work creation:
> kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
> kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
> insert_work+0x3d/0x330 kernel/workqueue.c:2180
> __queue_work+0xcd0/0xf90 kernel/workqueue.c:2335
> queue_work_on+0x106/0x1c0 kernel/workqueue.c:2386
> queue_work include/linux/workqueue.h:669 [inline]
> schedule_work include/linux/workqueue.h:730 [inline]
> f2fs_handle_critical_error+0x255/0x540 fs/f2fs/super.c:4624
> f2fs_write_end_io+0x886/0xb60 fs/f2fs/data.c:351
> __submit_merged_bio+0x256/0x660 fs/f2fs/data.c:540
> __f2fs_submit_merged_write fs/f2fs/data.c:635 [inline]
> __submit_merged_write_cond+0x471/0x530 fs/f2fs/data.c:657
> f2fs_sync_node_pages+0x1479/0x15e0 fs/f2fs/node.c:2166
> block_operations fs/f2fs/checkpoint.c:1276 [inline]
> f2fs_write_checkpoint+0xdd5/0x2430 fs/f2fs/checkpoint.c:1678
> kill_f2fs_super+0x2d2/0x6c0 fs/f2fs/super.c:5448
> deactivate_locked_super+0xbc/0x130 fs/super.c:474
> cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
> task_work_run+0x1d4/0x260 kernel/task_work.c:233
> exit_task_work include/linux/task_work.h:40 [inline]
> do_exit+0x694/0x22f0 kernel/exit.c:971
> do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
> __do_sys_exit_group kernel/exit.c:1123 [inline]
> __se_sys_exit_group kernel/exit.c:1121 [inline]
> __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
> __pfx_syscall_get_nr+0x0/0x10 arch/x86/include/generated/asm/syscalls_64.h:232
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Second to last potentially related work creation:
> kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
> kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
> insert_work+0x3d/0x330 kernel/workqueue.c:2180
> __queue_work+0xcd0/0xf90 kernel/workqueue.c:2335
> queue_work_on+0x106/0x1c0 kernel/workqueue.c:2386
> sanity_check_node_footer fs/f2fs/node.c:1536 [inline]
> __get_node_folio+0xcaf/0x14f0 fs/f2fs/node.c:1581
> do_read_inode fs/f2fs/inode.c:425 [inline]
> f2fs_iget+0x77c/0x5640 fs/f2fs/inode.c:596
> f2fs_nfs_get_inode+0x76/0x110 fs/f2fs/super.c:3723
> generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1498
> exportfs_decode_fh_raw+0x178/0x6e0 fs/exportfs/expfs.c:456
> do_handle_to_path+0xa4/0x1a0 fs/fhandle.c:276
> handle_to_path fs/fhandle.c:400 [inline]
> do_handle_open+0x6a1/0x930 fs/fhandle.c:424
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> The buggy address belongs to the object at ffff88804357c000
> which belongs to the cache kmalloc-8k of size 8192
> The buggy address is located 4464 bytes inside of
> freed 8192-byte region [ffff88804357c000, ffff88804357e000)
>
> The buggy address belongs to the physical page:
> page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x43578
> head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
> flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
> page_type: f5(slab)
> raw: 04fff00000000040 ffff88801a442280 ffffea000046b000 0000000000000002
> raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
> head: 04fff00000000040 ffff88801a442280 ffffea000046b000 0000000000000002
> head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
> head: 04fff00000000003 ffffea00010d5e01 00000000ffffffff 00000000ffffffff
> head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
> page dumped because: kasan: bad access detected
> page_owner tracks the page as allocated
> page last allocated via order 3, migratetype Unmovable, gfp_mask 0x528c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP), pid 5411, tgid 5411 (syz-executor), ts 97414573985, free_ts 95403368329
> set_page_owner include/linux/page_owner.h:32 [inline]
> post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
> prep_new_page mm/page_alloc.c:1854 [inline]
> get_page_from_freelist+0x24e0/0x2580 mm/page_alloc.c:3915
> __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
> alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
> alloc_slab_page mm/slub.c:3075 [inline]
> allocate_slab+0x86/0x3b0 mm/slub.c:3248
> new_slab mm/slub.c:3302 [inline]
> ___slab_alloc+0xe53/0x1820 mm/slub.c:4656
> __slab_alloc+0x65/0x100 mm/slub.c:4779
> __slab_alloc_node mm/slub.c:4855 [inline]
> slab_alloc_node mm/slub.c:5251 [inline]
> __do_kmalloc_node mm/slub.c:5656 [inline]
> __kvmalloc_node_noprof+0x6b6/0x920 mm/slub.c:7136
> kvmalloc_array_node_noprof include/linux/slab.h:1122 [inline]
> __ptr_ring_init_queue_alloc_noprof include/linux/ptr_ring.h:481 [inline]
> ptr_ring_init_noprof include/linux/ptr_ring.h:499 [inline]
> wg_packet_queue_init+0xbc/0x320 drivers/net/wireguard/queueing.c:32
> wg_newlink+0x2f6/0x670 drivers/net/wireguard/device.c:352
> rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3840
> __rtnl_newlink net/core/rtnetlink.c:3957 [inline]
> rtnl_newlink+0x16e7/0x1c90 net/core/rtnetlink.c:4072
> rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
> netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
> netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
> netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
> netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
> page last free pid 4363 tgid 4363 stack trace:
> reset_page_owner include/linux/page_owner.h:25 [inline]
> free_pages_prepare mm/page_alloc.c:1395 [inline]
> __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
> unix_net_exit+0x6b/0xb0 net/unix/af_unix.c:3837
> ops_exit_list net/core/net_namespace.c:199 [inline]
> ops_undo_list+0x49a/0x990 net/core/net_namespace.c:252
> cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696
> process_one_work kernel/workqueue.c:3257 [inline]
> process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
> worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
> kthread+0x711/0x8a0 kernel/kthread.c:463
> ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
>
> Memory state around the buggy address:
> ffff88804357d000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88804357d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ffff88804357d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff88804357d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88804357d200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
^ permalink raw reply [flat|nested] 11+ messages in thread* Forwarded: Re: [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2)
2025-12-22 4:08 [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2) syzbot
2026-01-07 2:04 ` Chao Yu
2026-01-07 6:44 ` Forwarded: " syzbot
@ 2026-01-07 8:49 ` syzbot
2026-01-07 9:50 ` Chao Yu
2026-01-07 10:59 ` Chao Yu
4 siblings, 0 replies; 11+ messages in thread
From: syzbot @ 2026-01-07 8:49 UTC (permalink / raw)
To: linux-kernel
For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.
***
Subject: Re: [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2)
Author: chao@kernel.org
#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git bugfix/syzbot
On 12/22/2025 12:08 PM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 765b233a9b94 Merge tag 'i2c-for-6.19-rc2' of git://git.ker..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=17a56b1a580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=513255d80ab78f2b
> dashboard link: https://syzkaller.appspot.com/bug?extid=b4444e3c972a7a124187
> compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=174b0b58580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=162f8b1a580000
>
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-765b233a.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/f8288fd6c7cc/vmlinux-765b233a.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/2a2ef1044b19/bzImage-765b233a.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/333719a5e15d/mount_1.gz
> fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=17faddb4580000)
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+b4444e3c972a7a124187@syzkaller.appspotmail.com
>
> ==================================================================
> BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline]
> BUG: KASAN: slab-use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
> BUG: KASAN: slab-use-after-free in get_pages fs/f2fs/f2fs.h:2718 [inline]
> BUG: KASAN: slab-use-after-free in f2fs_write_end_io+0x9b9/0xb60 fs/f2fs/data.c:364
> Read of size 4 at addr ffff88804357d170 by task kworker/u4:4/45
>
> CPU: 0 UID: 0 PID: 45 Comm: kworker/u4:4 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
> Workqueue: loop0 loop_workfn
> Call Trace:
> <TASK>
> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
> print_address_description mm/kasan/report.c:378 [inline]
> print_report+0xca/0x240 mm/kasan/report.c:482
> kasan_report+0x118/0x150 mm/kasan/report.c:595
> check_region_inline mm/kasan/generic.c:-1 [inline]
> kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200
> instrument_atomic_read include/linux/instrumented.h:68 [inline]
> atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
> get_pages fs/f2fs/f2fs.h:2718 [inline]
> f2fs_write_end_io+0x9b9/0xb60 fs/f2fs/data.c:364
> blk_update_request+0x57e/0xe60 block/blk-mq.c:1007
> blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1169
> lo_rw_aio_complete drivers/block/loop.c:337 [inline]
> lo_rw_aio+0xcd1/0xef0 drivers/block/loop.c:410
> do_req_filebacked drivers/block/loop.c:-1 [inline]
> loop_handle_cmd drivers/block/loop.c:1926 [inline]
> loop_process_work+0x8fe/0x10b0 drivers/block/loop.c:1961
> process_one_work kernel/workqueue.c:3257 [inline]
> process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
> worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
> kthread+0x711/0x8a0 kernel/kthread.c:463
> ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
> </TASK>
>
> Allocated by task 5484:
> kasan_save_stack mm/kasan/common.c:56 [inline]
> kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
> poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
> __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
> kasan_kmalloc include/linux/kasan.h:262 [inline]
> __kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5776
> kmalloc_noprof include/linux/slab.h:957 [inline]
> kzalloc_noprof include/linux/slab.h:1094 [inline]
> f2fs_fill_super+0x8c/0x6ec0 fs/f2fs/super.c:4895
> get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
> vfs_get_tree+0x92/0x2a0 fs/super.c:1751
> fc_mount fs/namespace.c:1199 [inline]
> do_new_mount_fc fs/namespace.c:3636 [inline]
> do_new_mount+0x302/0xa10 fs/namespace.c:3712
> do_mount fs/namespace.c:4035 [inline]
> __do_sys_mount fs/namespace.c:4224 [inline]
> __se_sys_mount+0x313/0x410 fs/namespace.c:4201
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Freed by task 5484:
> kasan_save_stack mm/kasan/common.c:56 [inline]
> kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
> kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
> poison_slab_object mm/kasan/common.c:252 [inline]
> __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
> kasan_slab_free include/linux/kasan.h:234 [inline]
> slab_free_hook mm/slub.c:2540 [inline]
> slab_free mm/slub.c:6670 [inline]
> kfree+0x1c0/0x660 mm/slub.c:6878
> kill_f2fs_super+0x5b6/0x6c0 fs/f2fs/super.c:5458
> deactivate_locked_super+0xbc/0x130 fs/super.c:474
> cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
> task_work_run+0x1d4/0x260 kernel/task_work.c:233
> exit_task_work include/linux/task_work.h:40 [inline]
> do_exit+0x694/0x22f0 kernel/exit.c:971
> do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
> __do_sys_exit_group kernel/exit.c:1123 [inline]
> __se_sys_exit_group kernel/exit.c:1121 [inline]
> __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
> __pfx_syscall_get_nr+0x0/0x10 arch/x86/include/generated/asm/syscalls_64.h:232
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Last potentially related work creation:
> kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
> kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
> insert_work+0x3d/0x330 kernel/workqueue.c:2180
> __queue_work+0xcd0/0xf90 kernel/workqueue.c:2335
> queue_work_on+0x106/0x1c0 kernel/workqueue.c:2386
> queue_work include/linux/workqueue.h:669 [inline]
> schedule_work include/linux/workqueue.h:730 [inline]
> f2fs_handle_critical_error+0x255/0x540 fs/f2fs/super.c:4624
> f2fs_write_end_io+0x886/0xb60 fs/f2fs/data.c:351
> __submit_merged_bio+0x256/0x660 fs/f2fs/data.c:540
> __f2fs_submit_merged_write fs/f2fs/data.c:635 [inline]
> __submit_merged_write_cond+0x471/0x530 fs/f2fs/data.c:657
> f2fs_sync_node_pages+0x1479/0x15e0 fs/f2fs/node.c:2166
> block_operations fs/f2fs/checkpoint.c:1276 [inline]
> f2fs_write_checkpoint+0xdd5/0x2430 fs/f2fs/checkpoint.c:1678
> kill_f2fs_super+0x2d2/0x6c0 fs/f2fs/super.c:5448
> deactivate_locked_super+0xbc/0x130 fs/super.c:474
> cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
> task_work_run+0x1d4/0x260 kernel/task_work.c:233
> exit_task_work include/linux/task_work.h:40 [inline]
> do_exit+0x694/0x22f0 kernel/exit.c:971
> do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
> __do_sys_exit_group kernel/exit.c:1123 [inline]
> __se_sys_exit_group kernel/exit.c:1121 [inline]
> __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
> __pfx_syscall_get_nr+0x0/0x10 arch/x86/include/generated/asm/syscalls_64.h:232
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Second to last potentially related work creation:
> kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
> kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
> insert_work+0x3d/0x330 kernel/workqueue.c:2180
> __queue_work+0xcd0/0xf90 kernel/workqueue.c:2335
> queue_work_on+0x106/0x1c0 kernel/workqueue.c:2386
> sanity_check_node_footer fs/f2fs/node.c:1536 [inline]
> __get_node_folio+0xcaf/0x14f0 fs/f2fs/node.c:1581
> do_read_inode fs/f2fs/inode.c:425 [inline]
> f2fs_iget+0x77c/0x5640 fs/f2fs/inode.c:596
> f2fs_nfs_get_inode+0x76/0x110 fs/f2fs/super.c:3723
> generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1498
> exportfs_decode_fh_raw+0x178/0x6e0 fs/exportfs/expfs.c:456
> do_handle_to_path+0xa4/0x1a0 fs/fhandle.c:276
> handle_to_path fs/fhandle.c:400 [inline]
> do_handle_open+0x6a1/0x930 fs/fhandle.c:424
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> The buggy address belongs to the object at ffff88804357c000
> which belongs to the cache kmalloc-8k of size 8192
> The buggy address is located 4464 bytes inside of
> freed 8192-byte region [ffff88804357c000, ffff88804357e000)
>
> The buggy address belongs to the physical page:
> page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x43578
> head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
> flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
> page_type: f5(slab)
> raw: 04fff00000000040 ffff88801a442280 ffffea000046b000 0000000000000002
> raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
> head: 04fff00000000040 ffff88801a442280 ffffea000046b000 0000000000000002
> head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
> head: 04fff00000000003 ffffea00010d5e01 00000000ffffffff 00000000ffffffff
> head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
> page dumped because: kasan: bad access detected
> page_owner tracks the page as allocated
> page last allocated via order 3, migratetype Unmovable, gfp_mask 0x528c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP), pid 5411, tgid 5411 (syz-executor), ts 97414573985, free_ts 95403368329
> set_page_owner include/linux/page_owner.h:32 [inline]
> post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
> prep_new_page mm/page_alloc.c:1854 [inline]
> get_page_from_freelist+0x24e0/0x2580 mm/page_alloc.c:3915
> __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
> alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
> alloc_slab_page mm/slub.c:3075 [inline]
> allocate_slab+0x86/0x3b0 mm/slub.c:3248
> new_slab mm/slub.c:3302 [inline]
> ___slab_alloc+0xe53/0x1820 mm/slub.c:4656
> __slab_alloc+0x65/0x100 mm/slub.c:4779
> __slab_alloc_node mm/slub.c:4855 [inline]
> slab_alloc_node mm/slub.c:5251 [inline]
> __do_kmalloc_node mm/slub.c:5656 [inline]
> __kvmalloc_node_noprof+0x6b6/0x920 mm/slub.c:7136
> kvmalloc_array_node_noprof include/linux/slab.h:1122 [inline]
> __ptr_ring_init_queue_alloc_noprof include/linux/ptr_ring.h:481 [inline]
> ptr_ring_init_noprof include/linux/ptr_ring.h:499 [inline]
> wg_packet_queue_init+0xbc/0x320 drivers/net/wireguard/queueing.c:32
> wg_newlink+0x2f6/0x670 drivers/net/wireguard/device.c:352
> rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3840
> __rtnl_newlink net/core/rtnetlink.c:3957 [inline]
> rtnl_newlink+0x16e7/0x1c90 net/core/rtnetlink.c:4072
> rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
> netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
> netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
> netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
> netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
> page last free pid 4363 tgid 4363 stack trace:
> reset_page_owner include/linux/page_owner.h:25 [inline]
> free_pages_prepare mm/page_alloc.c:1395 [inline]
> __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
> unix_net_exit+0x6b/0xb0 net/unix/af_unix.c:3837
> ops_exit_list net/core/net_namespace.c:199 [inline]
> ops_undo_list+0x49a/0x990 net/core/net_namespace.c:252
> cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696
> process_one_work kernel/workqueue.c:3257 [inline]
> process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
> worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
> kthread+0x711/0x8a0 kernel/kthread.c:463
> ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
>
> Memory state around the buggy address:
> ffff88804357d000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88804357d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ffff88804357d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff88804357d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88804357d200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2)
2025-12-22 4:08 [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2) syzbot
` (2 preceding siblings ...)
2026-01-07 8:49 ` syzbot
@ 2026-01-07 9:50 ` Chao Yu
2026-01-07 10:05 ` syzbot
2026-01-07 10:59 ` Chao Yu
4 siblings, 1 reply; 11+ messages in thread
From: Chao Yu @ 2026-01-07 9:50 UTC (permalink / raw)
To: syzbot, linux-f2fs-devel, linux-kernel, syzkaller-bugs; +Cc: chao
#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git bugfix/syzbot
On 12/22/2025 12:08 PM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 765b233a9b94 Merge tag 'i2c-for-6.19-rc2' of git://git.ker..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=17a56b1a580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=513255d80ab78f2b
> dashboard link: https://syzkaller.appspot.com/bug?extid=b4444e3c972a7a124187
> compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=174b0b58580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=162f8b1a580000
>
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-765b233a.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/f8288fd6c7cc/vmlinux-765b233a.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/2a2ef1044b19/bzImage-765b233a.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/333719a5e15d/mount_1.gz
> fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=17faddb4580000)
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+b4444e3c972a7a124187@syzkaller.appspotmail.com
>
> ==================================================================
> BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline]
> BUG: KASAN: slab-use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
> BUG: KASAN: slab-use-after-free in get_pages fs/f2fs/f2fs.h:2718 [inline]
> BUG: KASAN: slab-use-after-free in f2fs_write_end_io+0x9b9/0xb60 fs/f2fs/data.c:364
> Read of size 4 at addr ffff88804357d170 by task kworker/u4:4/45
>
> CPU: 0 UID: 0 PID: 45 Comm: kworker/u4:4 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
> Workqueue: loop0 loop_workfn
> Call Trace:
> <TASK>
> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
> print_address_description mm/kasan/report.c:378 [inline]
> print_report+0xca/0x240 mm/kasan/report.c:482
> kasan_report+0x118/0x150 mm/kasan/report.c:595
> check_region_inline mm/kasan/generic.c:-1 [inline]
> kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200
> instrument_atomic_read include/linux/instrumented.h:68 [inline]
> atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
> get_pages fs/f2fs/f2fs.h:2718 [inline]
> f2fs_write_end_io+0x9b9/0xb60 fs/f2fs/data.c:364
> blk_update_request+0x57e/0xe60 block/blk-mq.c:1007
> blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1169
> lo_rw_aio_complete drivers/block/loop.c:337 [inline]
> lo_rw_aio+0xcd1/0xef0 drivers/block/loop.c:410
> do_req_filebacked drivers/block/loop.c:-1 [inline]
> loop_handle_cmd drivers/block/loop.c:1926 [inline]
> loop_process_work+0x8fe/0x10b0 drivers/block/loop.c:1961
> process_one_work kernel/workqueue.c:3257 [inline]
> process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
> worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
> kthread+0x711/0x8a0 kernel/kthread.c:463
> ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
> </TASK>
>
> Allocated by task 5484:
> kasan_save_stack mm/kasan/common.c:56 [inline]
> kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
> poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
> __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
> kasan_kmalloc include/linux/kasan.h:262 [inline]
> __kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5776
> kmalloc_noprof include/linux/slab.h:957 [inline]
> kzalloc_noprof include/linux/slab.h:1094 [inline]
> f2fs_fill_super+0x8c/0x6ec0 fs/f2fs/super.c:4895
> get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
> vfs_get_tree+0x92/0x2a0 fs/super.c:1751
> fc_mount fs/namespace.c:1199 [inline]
> do_new_mount_fc fs/namespace.c:3636 [inline]
> do_new_mount+0x302/0xa10 fs/namespace.c:3712
> do_mount fs/namespace.c:4035 [inline]
> __do_sys_mount fs/namespace.c:4224 [inline]
> __se_sys_mount+0x313/0x410 fs/namespace.c:4201
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Freed by task 5484:
> kasan_save_stack mm/kasan/common.c:56 [inline]
> kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
> kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
> poison_slab_object mm/kasan/common.c:252 [inline]
> __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
> kasan_slab_free include/linux/kasan.h:234 [inline]
> slab_free_hook mm/slub.c:2540 [inline]
> slab_free mm/slub.c:6670 [inline]
> kfree+0x1c0/0x660 mm/slub.c:6878
> kill_f2fs_super+0x5b6/0x6c0 fs/f2fs/super.c:5458
> deactivate_locked_super+0xbc/0x130 fs/super.c:474
> cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
> task_work_run+0x1d4/0x260 kernel/task_work.c:233
> exit_task_work include/linux/task_work.h:40 [inline]
> do_exit+0x694/0x22f0 kernel/exit.c:971
> do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
> __do_sys_exit_group kernel/exit.c:1123 [inline]
> __se_sys_exit_group kernel/exit.c:1121 [inline]
> __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
> __pfx_syscall_get_nr+0x0/0x10 arch/x86/include/generated/asm/syscalls_64.h:232
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Last potentially related work creation:
> kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
> kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
> insert_work+0x3d/0x330 kernel/workqueue.c:2180
> __queue_work+0xcd0/0xf90 kernel/workqueue.c:2335
> queue_work_on+0x106/0x1c0 kernel/workqueue.c:2386
> queue_work include/linux/workqueue.h:669 [inline]
> schedule_work include/linux/workqueue.h:730 [inline]
> f2fs_handle_critical_error+0x255/0x540 fs/f2fs/super.c:4624
> f2fs_write_end_io+0x886/0xb60 fs/f2fs/data.c:351
> __submit_merged_bio+0x256/0x660 fs/f2fs/data.c:540
> __f2fs_submit_merged_write fs/f2fs/data.c:635 [inline]
> __submit_merged_write_cond+0x471/0x530 fs/f2fs/data.c:657
> f2fs_sync_node_pages+0x1479/0x15e0 fs/f2fs/node.c:2166
> block_operations fs/f2fs/checkpoint.c:1276 [inline]
> f2fs_write_checkpoint+0xdd5/0x2430 fs/f2fs/checkpoint.c:1678
> kill_f2fs_super+0x2d2/0x6c0 fs/f2fs/super.c:5448
> deactivate_locked_super+0xbc/0x130 fs/super.c:474
> cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
> task_work_run+0x1d4/0x260 kernel/task_work.c:233
> exit_task_work include/linux/task_work.h:40 [inline]
> do_exit+0x694/0x22f0 kernel/exit.c:971
> do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
> __do_sys_exit_group kernel/exit.c:1123 [inline]
> __se_sys_exit_group kernel/exit.c:1121 [inline]
> __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
> __pfx_syscall_get_nr+0x0/0x10 arch/x86/include/generated/asm/syscalls_64.h:232
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Second to last potentially related work creation:
> kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
> kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
> insert_work+0x3d/0x330 kernel/workqueue.c:2180
> __queue_work+0xcd0/0xf90 kernel/workqueue.c:2335
> queue_work_on+0x106/0x1c0 kernel/workqueue.c:2386
> sanity_check_node_footer fs/f2fs/node.c:1536 [inline]
> __get_node_folio+0xcaf/0x14f0 fs/f2fs/node.c:1581
> do_read_inode fs/f2fs/inode.c:425 [inline]
> f2fs_iget+0x77c/0x5640 fs/f2fs/inode.c:596
> f2fs_nfs_get_inode+0x76/0x110 fs/f2fs/super.c:3723
> generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1498
> exportfs_decode_fh_raw+0x178/0x6e0 fs/exportfs/expfs.c:456
> do_handle_to_path+0xa4/0x1a0 fs/fhandle.c:276
> handle_to_path fs/fhandle.c:400 [inline]
> do_handle_open+0x6a1/0x930 fs/fhandle.c:424
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> The buggy address belongs to the object at ffff88804357c000
> which belongs to the cache kmalloc-8k of size 8192
> The buggy address is located 4464 bytes inside of
> freed 8192-byte region [ffff88804357c000, ffff88804357e000)
>
> The buggy address belongs to the physical page:
> page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x43578
> head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
> flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
> page_type: f5(slab)
> raw: 04fff00000000040 ffff88801a442280 ffffea000046b000 0000000000000002
> raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
> head: 04fff00000000040 ffff88801a442280 ffffea000046b000 0000000000000002
> head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
> head: 04fff00000000003 ffffea00010d5e01 00000000ffffffff 00000000ffffffff
> head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
> page dumped because: kasan: bad access detected
> page_owner tracks the page as allocated
> page last allocated via order 3, migratetype Unmovable, gfp_mask 0x528c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP), pid 5411, tgid 5411 (syz-executor), ts 97414573985, free_ts 95403368329
> set_page_owner include/linux/page_owner.h:32 [inline]
> post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
> prep_new_page mm/page_alloc.c:1854 [inline]
> get_page_from_freelist+0x24e0/0x2580 mm/page_alloc.c:3915
> __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
> alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
> alloc_slab_page mm/slub.c:3075 [inline]
> allocate_slab+0x86/0x3b0 mm/slub.c:3248
> new_slab mm/slub.c:3302 [inline]
> ___slab_alloc+0xe53/0x1820 mm/slub.c:4656
> __slab_alloc+0x65/0x100 mm/slub.c:4779
> __slab_alloc_node mm/slub.c:4855 [inline]
> slab_alloc_node mm/slub.c:5251 [inline]
> __do_kmalloc_node mm/slub.c:5656 [inline]
> __kvmalloc_node_noprof+0x6b6/0x920 mm/slub.c:7136
> kvmalloc_array_node_noprof include/linux/slab.h:1122 [inline]
> __ptr_ring_init_queue_alloc_noprof include/linux/ptr_ring.h:481 [inline]
> ptr_ring_init_noprof include/linux/ptr_ring.h:499 [inline]
> wg_packet_queue_init+0xbc/0x320 drivers/net/wireguard/queueing.c:32
> wg_newlink+0x2f6/0x670 drivers/net/wireguard/device.c:352
> rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3840
> __rtnl_newlink net/core/rtnetlink.c:3957 [inline]
> rtnl_newlink+0x16e7/0x1c90 net/core/rtnetlink.c:4072
> rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
> netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
> netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
> netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
> netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
> page last free pid 4363 tgid 4363 stack trace:
> reset_page_owner include/linux/page_owner.h:25 [inline]
> free_pages_prepare mm/page_alloc.c:1395 [inline]
> __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
> unix_net_exit+0x6b/0xb0 net/unix/af_unix.c:3837
> ops_exit_list net/core/net_namespace.c:199 [inline]
> ops_undo_list+0x49a/0x990 net/core/net_namespace.c:252
> cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696
> process_one_work kernel/workqueue.c:3257 [inline]
> process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
> worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
> kthread+0x711/0x8a0 kernel/kthread.c:463
> ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
>
> Memory state around the buggy address:
> ffff88804357d000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88804357d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ffff88804357d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff88804357d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88804357d200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2)
2026-01-07 9:50 ` Chao Yu
@ 2026-01-07 10:05 ` syzbot
0 siblings, 0 replies; 11+ messages in thread
From: syzbot @ 2026-01-07 10:05 UTC (permalink / raw)
To: chao, linux-f2fs-devel, linux-kernel, syzkaller-bugs
Hello,
syzbot tried to test the proposed patch but the build/boot failed:
50:50:50
[ 96.324372][ T4608] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 96.383532][ T13] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 96.388909][ T13] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 98.981820][ T4685] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[ 98.986155][ T4685] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[ 98.989980][ T4685] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[ 98.993960][ T4685] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[ 98.997492][ T4685] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[ 101.080148][ T5400] chnl_net:caif_netlink_parms(): no params data found
[ 101.260660][ T5400] bridge0: port 1(bridge_slave_0) entered blocking state
[ 101.271979][ T5400] bridge0: port 1(bridge_slave_0) entered disabled state
[ 101.275128][ T5400] bridge_slave_0: entered allmulticast mode
[ 101.291786][ T5400] bridge_slave_0: entered promiscuous mode
[ 101.298693][ T5400] bridge0: port 2(bridge_slave_1) entered blocking state
[ 101.309121][ T5400] bridge0: port 2(bridge_slave_1) entered disabled state
[ 101.312608][ T5400] bridge_slave_1: entered allmulticast mode
[ 101.321527][ T5400] bridge_slave_1: entered promiscuous mode
[ 101.374348][ T5400] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 101.394422][ T5400] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 101.443124][ T5400] team0: Port device team_slave_0 added
[ 101.452091][ T5400] team0: Port device team_slave_1 added
[ 101.495794][ T5400] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 101.498939][ T5400] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 101.541327][ T5400] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 101.571912][ T5400] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 101.574976][ T5400] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 101.611346][ T5400] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 101.716466][ T5400] hsr_slave_0: entered promiscuous mode
[ 101.720143][ T5400] hsr_slave_1: entered promiscuous mode
[ 102.035333][ T5400] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 102.057801][ T5400] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 102.066664][ T5400] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 102.085706][ T5400] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 102.225047][ T5400] 8021q: adding VLAN 0 to HW filter on device bond0
[ 102.254868][ T5400] 8021q: adding VLAN 0 to HW filter on device team0
[ 102.295073][ T1127] bridge0: port 1(bridge_slave_0) entered blocking state
[ 102.298513][ T1127] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 102.313626][ T1127] bridge0: port 2(bridge_slave_1) entered blocking state
[ 102.316779][ T1127] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 102.538955][ T5400] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 102.576951][ T5400] veth0_vlan: entered promiscuous mode
[ 102.584258][ T5400] veth1_vlan: entered promiscuous mode
[ 102.606836][ T5400] veth0_macvtap: entered promiscuous mode
[ 102.617483][ T5400] veth1_macvtap: entered promiscuous mode
[ 102.631115][ T5400] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 102.644037][ T5400] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 102.656266][ T4637] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[ 102.667017][ T4637] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[ 102.678832][ T4637] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[ 102.699431][ T4637] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[ 102.827338][ T4637] netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 102.874563][ T4637] netdevsim netdevsim0 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 102.916861][ T4637] netdevsim netdevsim0 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 102.955081][ T4637] netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
2026/01/07 10:04:23 executed programs: 0
[ 103.704543][ T47] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[ 103.708655][ T47] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[ 103.713035][ T47] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[ 103.716711][ T47] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[ 103.720706][ T47] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[ 103.874928][ T5441] chnl_net:caif_netlink_parms(): no params data found
[ 104.002432][ T5441] bridge0: port 1(bridge_slave_0) entered blocking state
[ 104.005631][ T5441] bridge0: port 1(bridge_slave_0) entered disabled state
[ 104.009058][ T5441] bridge_slave_0: entered allmulticast mode
[ 104.025056][ T5441] bridge_slave_0: entered promiscuous mode
[ 104.033625][ T5441] bridge0: port 2(bridge_slave_1) entered blocking state
[ 104.037020][ T5441] bridge0: port 2(bridge_slave_1) entered disabled state
[ 104.040130][ T5441] bridge_slave_1: entered allmulticast mode
[ 104.053666][ T5441] bridge_slave_1: entered promiscuous mode
[ 104.115026][ T5441] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 104.136512][ T5441] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 104.178539][ T5441] team0: Port device team_slave_0 added
[ 104.183425][ T5441] team0: Port device team_slave_1 added
[ 104.207708][ T5441] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 104.210805][ T5441] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 104.223299][ T5441] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 104.230664][ T5441] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 104.234253][ T5441] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 104.246544][ T5441] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 104.281972][ T5441] hsr_slave_0: entered promiscuous mode
[ 104.285329][ T5441] hsr_slave_1: entered promiscuous mode
[ 104.288328][ T5441] debugfs: 'hsr0' already exists in 'hsr'
[ 104.290838][ T5441] Cannot create hsr debugfs directory
[ 105.062924][ T4637] bridge_slave_1: left allmulticast mode
[ 105.065283][ T4637] bridge_slave_1: left promiscuous mode
[ 105.072635][ T4637] bridge0: port 2(bridge_slave_1) entered disabled state
[ 105.084121][ T4637] bridge_slave_0: left allmulticast mode
[ 105.086616][ T4637] bridge_slave_0: left promiscuous mode
[ 105.089229][ T4637] bridge0: port 1(bridge_slave_0) entered disabled state
[ 105.434250][ T4637] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
[ 105.441979][ T4637] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
[ 105.446733][ T4637] bond0 (unregistering): Released all slaves
[ 105.546762][ T4637] hsr_slave_0: left promiscuous mode
[ 105.561587][ T4637] hsr_slave_1: left promiscuous mode
[ 105.564672][ T4637] batman_adv: batadv0: Interface deactivated: batadv_slave_0
[ 105.568054][ T4637] batman_adv: batadv0: Removing interface: batadv_slave_0
[ 105.578013][ T4637] batman_adv: batadv0: Interface deactivated: batadv_slave_1
[ 105.581111][ T4637] batman_adv: batadv0: Removing interface: batadv_slave_1
[ 105.608041][ T4637] veth1_macvtap: left promiscuous mode
[ 105.610648][ T4637] veth0_macvtap: left promiscuous mode
[ 105.628271][ T4637] veth1_vlan: left promiscuous mode
[ 105.632462][ T4637] veth0_vlan: left promiscuous mode
[ 105.736315][ T47] Bluetooth: hci0: command tx timeout
[ 106.107211][ T4637] team0 (unregistering): Port device team_slave_1 removed
[ 106.134290][ T4637] team0 (unregistering): Port device team_slave_0 removed
[ 106.578691][ T5441] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 106.599515][ T5441] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 106.616734][ T5441] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 106.630262][ T5441] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 107.173027][ T5441] 8021q: adding VLAN 0 to HW filter on device bond0
[ 107.206957][ T5441] 8021q: adding VLAN 0 to HW filter on device team0
[ 107.255745][ T3440] bridge0: port 1(bridge_slave_0) entered blocking state
[ 107.259102][ T3440] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 107.305836][ T3440] bridge0: port 2(bridge_slave_1) entered blocking state
[ 107.309126][ T3440] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 107.468490][ T5441] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 107.504820][ T5441] veth0_vlan: entered promiscuous mode
[ 107.513636][ T5441] veth1_vlan: entered promiscuous mode
[ 107.533127][ T5441] veth0_macvtap: entered promiscuous mode
[ 107.538225][ T5441] veth1_macvtap: entered promiscuous mode
[ 107.551007][ T5441] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 107.563537][ T5441] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 107.573370][ T13] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[ 107.583446][ T13] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[ 107.587551][ T13] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[ 107.620236][ T13] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[ 107.687153][ T3440] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 107.690521][ T3440] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 107.739992][ T13] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 107.744091][ T13] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 107.821622][ T47] Bluetooth: hci0: command tx timeout
SYZFAIL: failed to recv rpc
fd=3 want=4 recv=0 n=0 (errno 9: Bad file descriptor)
[ 109.064804][ T3440] netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 110.112799][ T3440] netdevsim netdevsim0 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 110.530922][ T3440] netdevsim netdevsim0 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 110.573006][ T3440] netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 110.696901][ T3440] bridge_slave_1: left allmulticast mode
[ 110.699371][ T3440] bridge_slave_1: left promiscuous mode
[ 110.712675][ T3440] bridge0: port 2(bridge_slave_1) entered disabled state
[ 110.717544][ T3440] bridge_slave_0: left allmulticast mode
[ 110.720008][ T3440] bridge_slave_0: left promiscuous mode
[ 110.724098][ T3440] bridge0: port 1(bridge_slave_0) entered disabled state
[ 111.067299][ T3440] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
[ 111.073241][ T3440] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
[ 111.077962][ T3440] bond0 (unregistering): Released all slaves
[ 111.288410][ T3440] hsr_slave_0: left promiscuous mode
[ 111.290938][ T3440] hsr_slave_1: left promiscuous mode
[ 111.302397][ T3440] batman_adv: batadv0: Interface deactivated: batadv_slave_0
[ 111.305777][ T3440] batman_adv: batadv0: Removing interface: batadv_slave_0
[ 111.326508][ T3440] batman_adv: batadv0: Interface deactivated: batadv_slave_1
[ 111.329929][ T3440] batman_adv: batadv0: Removing interface: batadv_slave_1
[ 111.348723][ T3440] veth1_macvtap: left promiscuous mode
[ 111.362446][ T3440] veth0_macvtap: left promiscuous mode
[ 111.365101][ T3440] veth1_vlan: left promiscuous mode
[ 111.367513][ T3440] veth0_vlan: left promiscuous mode
[ 111.699085][ T3440] team0 (unregistering): Port device team_slave_1 removed
[ 111.720608][ T3440] team0 (unregistering): Port device team_slave_0 removed
syzkaller build log:
go env (err=<nil>)
AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE='auto'
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/syzkaller/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/syzkaller/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build1275535676=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOMODCACHE='/syzkaller/jobs/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs/linux/gopath'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/syzkaller/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.24.4'
GOWORK=''
PKG_CONFIG='pkg-config'
git status (err=<nil>)
HEAD detached at d1b870e1003b
nothing to commit, working tree clean
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
go list -f '{{.Stale}}' -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d1b870e1003b52891d2196c1e2ee42fe905010ba -X github.com/google/syzkaller/prog.gitRevisionDate=20251128-125159" ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d1b870e1003b52891d2196c1e2ee42fe905010ba -X github.com/google/syzkaller/prog.gitRevisionDate=20251128-125159" ./sys/syz-sysgen
make .descriptions
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
bin/syz-sysgen
touch .descriptions
GOOS=linux GOARCH=amd64 go build -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d1b870e1003b52891d2196c1e2ee42fe905010ba -X github.com/google/syzkaller/prog.gitRevisionDate=20251128-125159" -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
mkdir -p ./bin/linux_amd64
g++ -o ./bin/linux_amd64/syz-executor executor/executor.cc \
-m64 -O2 -pthread -Wall -Werror -Wparentheses -Wunused-const-variable -Wframe-larger-than=16384 -Wno-stringop-overflow -Wno-array-bounds -Wno-format-overflow -Wno-unused-but-set-variable -Wno-unused-command-line-argument -static-pie -std=c++17 -I. -Iexecutor/_include -DGOOS_linux=1 -DGOARCH_amd64=1 \
-DHOSTGOOS_linux=1 -DGIT_REVISION=\"d1b870e1003b52891d2196c1e2ee42fe905010ba\"
/usr/bin/ld: /tmp/cc4qdZbn.o: in function `Connection::Connect(char const*, char const*)':
executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x104): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
./tools/check-syzos.sh 2>/dev/null
Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=15dbee9a580000
Tested on:
commit: 1860d530 f2fs: fix to avoid UAF in f2fs_write_end_io()
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git bugfix/syzbot
kernel config: https://syzkaller.appspot.com/x/.config?x=513255d80ab78f2b
dashboard link: https://syzkaller.appspot.com/bug?extid=b4444e3c972a7a124187
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Note: no patches were applied.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2)
2025-12-22 4:08 [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2) syzbot
` (3 preceding siblings ...)
2026-01-07 9:50 ` Chao Yu
@ 2026-01-07 10:59 ` Chao Yu
2026-01-07 11:14 ` syzbot
4 siblings, 1 reply; 11+ messages in thread
From: Chao Yu @ 2026-01-07 10:59 UTC (permalink / raw)
To: syzbot, linux-kernel, syzkaller-bugs; +Cc: chao
#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git bugfix/syzbot
On 12/22/2025 12:08 PM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 765b233a9b94 Merge tag 'i2c-for-6.19-rc2' of git://git.ker..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=17a56b1a580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=513255d80ab78f2b
> dashboard link: https://syzkaller.appspot.com/bug?extid=b4444e3c972a7a124187
> compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=174b0b58580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=162f8b1a580000
>
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-765b233a.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/f8288fd6c7cc/vmlinux-765b233a.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/2a2ef1044b19/bzImage-765b233a.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/333719a5e15d/mount_1.gz
> fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=17faddb4580000)
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+b4444e3c972a7a124187@syzkaller.appspotmail.com
>
> ==================================================================
> BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline]
> BUG: KASAN: slab-use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
> BUG: KASAN: slab-use-after-free in get_pages fs/f2fs/f2fs.h:2718 [inline]
> BUG: KASAN: slab-use-after-free in f2fs_write_end_io+0x9b9/0xb60 fs/f2fs/data.c:364
> Read of size 4 at addr ffff88804357d170 by task kworker/u4:4/45
>
> CPU: 0 UID: 0 PID: 45 Comm: kworker/u4:4 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
> Workqueue: loop0 loop_workfn
> Call Trace:
> <TASK>
> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
> print_address_description mm/kasan/report.c:378 [inline]
> print_report+0xca/0x240 mm/kasan/report.c:482
> kasan_report+0x118/0x150 mm/kasan/report.c:595
> check_region_inline mm/kasan/generic.c:-1 [inline]
> kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200
> instrument_atomic_read include/linux/instrumented.h:68 [inline]
> atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
> get_pages fs/f2fs/f2fs.h:2718 [inline]
> f2fs_write_end_io+0x9b9/0xb60 fs/f2fs/data.c:364
> blk_update_request+0x57e/0xe60 block/blk-mq.c:1007
> blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1169
> lo_rw_aio_complete drivers/block/loop.c:337 [inline]
> lo_rw_aio+0xcd1/0xef0 drivers/block/loop.c:410
> do_req_filebacked drivers/block/loop.c:-1 [inline]
> loop_handle_cmd drivers/block/loop.c:1926 [inline]
> loop_process_work+0x8fe/0x10b0 drivers/block/loop.c:1961
> process_one_work kernel/workqueue.c:3257 [inline]
> process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
> worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
> kthread+0x711/0x8a0 kernel/kthread.c:463
> ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
> </TASK>
>
> Allocated by task 5484:
> kasan_save_stack mm/kasan/common.c:56 [inline]
> kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
> poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
> __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
> kasan_kmalloc include/linux/kasan.h:262 [inline]
> __kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5776
> kmalloc_noprof include/linux/slab.h:957 [inline]
> kzalloc_noprof include/linux/slab.h:1094 [inline]
> f2fs_fill_super+0x8c/0x6ec0 fs/f2fs/super.c:4895
> get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
> vfs_get_tree+0x92/0x2a0 fs/super.c:1751
> fc_mount fs/namespace.c:1199 [inline]
> do_new_mount_fc fs/namespace.c:3636 [inline]
> do_new_mount+0x302/0xa10 fs/namespace.c:3712
> do_mount fs/namespace.c:4035 [inline]
> __do_sys_mount fs/namespace.c:4224 [inline]
> __se_sys_mount+0x313/0x410 fs/namespace.c:4201
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Freed by task 5484:
> kasan_save_stack mm/kasan/common.c:56 [inline]
> kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
> kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
> poison_slab_object mm/kasan/common.c:252 [inline]
> __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
> kasan_slab_free include/linux/kasan.h:234 [inline]
> slab_free_hook mm/slub.c:2540 [inline]
> slab_free mm/slub.c:6670 [inline]
> kfree+0x1c0/0x660 mm/slub.c:6878
> kill_f2fs_super+0x5b6/0x6c0 fs/f2fs/super.c:5458
> deactivate_locked_super+0xbc/0x130 fs/super.c:474
> cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
> task_work_run+0x1d4/0x260 kernel/task_work.c:233
> exit_task_work include/linux/task_work.h:40 [inline]
> do_exit+0x694/0x22f0 kernel/exit.c:971
> do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
> __do_sys_exit_group kernel/exit.c:1123 [inline]
> __se_sys_exit_group kernel/exit.c:1121 [inline]
> __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
> __pfx_syscall_get_nr+0x0/0x10 arch/x86/include/generated/asm/syscalls_64.h:232
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Last potentially related work creation:
> kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
> kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
> insert_work+0x3d/0x330 kernel/workqueue.c:2180
> __queue_work+0xcd0/0xf90 kernel/workqueue.c:2335
> queue_work_on+0x106/0x1c0 kernel/workqueue.c:2386
> queue_work include/linux/workqueue.h:669 [inline]
> schedule_work include/linux/workqueue.h:730 [inline]
> f2fs_handle_critical_error+0x255/0x540 fs/f2fs/super.c:4624
> f2fs_write_end_io+0x886/0xb60 fs/f2fs/data.c:351
> __submit_merged_bio+0x256/0x660 fs/f2fs/data.c:540
> __f2fs_submit_merged_write fs/f2fs/data.c:635 [inline]
> __submit_merged_write_cond+0x471/0x530 fs/f2fs/data.c:657
> f2fs_sync_node_pages+0x1479/0x15e0 fs/f2fs/node.c:2166
> block_operations fs/f2fs/checkpoint.c:1276 [inline]
> f2fs_write_checkpoint+0xdd5/0x2430 fs/f2fs/checkpoint.c:1678
> kill_f2fs_super+0x2d2/0x6c0 fs/f2fs/super.c:5448
> deactivate_locked_super+0xbc/0x130 fs/super.c:474
> cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
> task_work_run+0x1d4/0x260 kernel/task_work.c:233
> exit_task_work include/linux/task_work.h:40 [inline]
> do_exit+0x694/0x22f0 kernel/exit.c:971
> do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
> __do_sys_exit_group kernel/exit.c:1123 [inline]
> __se_sys_exit_group kernel/exit.c:1121 [inline]
> __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
> __pfx_syscall_get_nr+0x0/0x10 arch/x86/include/generated/asm/syscalls_64.h:232
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Second to last potentially related work creation:
> kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
> kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
> insert_work+0x3d/0x330 kernel/workqueue.c:2180
> __queue_work+0xcd0/0xf90 kernel/workqueue.c:2335
> queue_work_on+0x106/0x1c0 kernel/workqueue.c:2386
> sanity_check_node_footer fs/f2fs/node.c:1536 [inline]
> __get_node_folio+0xcaf/0x14f0 fs/f2fs/node.c:1581
> do_read_inode fs/f2fs/inode.c:425 [inline]
> f2fs_iget+0x77c/0x5640 fs/f2fs/inode.c:596
> f2fs_nfs_get_inode+0x76/0x110 fs/f2fs/super.c:3723
> generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1498
> exportfs_decode_fh_raw+0x178/0x6e0 fs/exportfs/expfs.c:456
> do_handle_to_path+0xa4/0x1a0 fs/fhandle.c:276
> handle_to_path fs/fhandle.c:400 [inline]
> do_handle_open+0x6a1/0x930 fs/fhandle.c:424
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> The buggy address belongs to the object at ffff88804357c000
> which belongs to the cache kmalloc-8k of size 8192
> The buggy address is located 4464 bytes inside of
> freed 8192-byte region [ffff88804357c000, ffff88804357e000)
>
> The buggy address belongs to the physical page:
> page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x43578
> head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
> flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
> page_type: f5(slab)
> raw: 04fff00000000040 ffff88801a442280 ffffea000046b000 0000000000000002
> raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
> head: 04fff00000000040 ffff88801a442280 ffffea000046b000 0000000000000002
> head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
> head: 04fff00000000003 ffffea00010d5e01 00000000ffffffff 00000000ffffffff
> head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
> page dumped because: kasan: bad access detected
> page_owner tracks the page as allocated
> page last allocated via order 3, migratetype Unmovable, gfp_mask 0x528c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP), pid 5411, tgid 5411 (syz-executor), ts 97414573985, free_ts 95403368329
> set_page_owner include/linux/page_owner.h:32 [inline]
> post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
> prep_new_page mm/page_alloc.c:1854 [inline]
> get_page_from_freelist+0x24e0/0x2580 mm/page_alloc.c:3915
> __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
> alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
> alloc_slab_page mm/slub.c:3075 [inline]
> allocate_slab+0x86/0x3b0 mm/slub.c:3248
> new_slab mm/slub.c:3302 [inline]
> ___slab_alloc+0xe53/0x1820 mm/slub.c:4656
> __slab_alloc+0x65/0x100 mm/slub.c:4779
> __slab_alloc_node mm/slub.c:4855 [inline]
> slab_alloc_node mm/slub.c:5251 [inline]
> __do_kmalloc_node mm/slub.c:5656 [inline]
> __kvmalloc_node_noprof+0x6b6/0x920 mm/slub.c:7136
> kvmalloc_array_node_noprof include/linux/slab.h:1122 [inline]
> __ptr_ring_init_queue_alloc_noprof include/linux/ptr_ring.h:481 [inline]
> ptr_ring_init_noprof include/linux/ptr_ring.h:499 [inline]
> wg_packet_queue_init+0xbc/0x320 drivers/net/wireguard/queueing.c:32
> wg_newlink+0x2f6/0x670 drivers/net/wireguard/device.c:352
> rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3840
> __rtnl_newlink net/core/rtnetlink.c:3957 [inline]
> rtnl_newlink+0x16e7/0x1c90 net/core/rtnetlink.c:4072
> rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
> netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
> netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
> netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
> netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
> page last free pid 4363 tgid 4363 stack trace:
> reset_page_owner include/linux/page_owner.h:25 [inline]
> free_pages_prepare mm/page_alloc.c:1395 [inline]
> __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
> unix_net_exit+0x6b/0xb0 net/unix/af_unix.c:3837
> ops_exit_list net/core/net_namespace.c:199 [inline]
> ops_undo_list+0x49a/0x990 net/core/net_namespace.c:252
> cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696
> process_one_work kernel/workqueue.c:3257 [inline]
> process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
> worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
> kthread+0x711/0x8a0 kernel/kthread.c:463
> ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
>
> Memory state around the buggy address:
> ffff88804357d000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88804357d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ffff88804357d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff88804357d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88804357d200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [syzbot] [f2fs?] KASAN: use-after-free Read in f2fs_write_end_io (2)
2026-01-07 10:59 ` Chao Yu
@ 2026-01-07 11:14 ` syzbot
0 siblings, 0 replies; 11+ messages in thread
From: syzbot @ 2026-01-07 11:14 UTC (permalink / raw)
To: chao, linux-kernel, syzkaller-bugs
Hello,
syzbot tried to test the proposed patch but the build/boot failed:
nfigured BSSID 50:50:50:50:50:50
[ 100.257856][ T2781] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 101.371932][ T5396] chnl_net:caif_netlink_parms(): no params data found
[ 101.453583][ T5396] bridge0: port 1(bridge_slave_0) entered blocking state
[ 101.457639][ T5396] bridge0: port 1(bridge_slave_0) entered disabled state
[ 101.460714][ T5396] bridge_slave_0: entered allmulticast mode
[ 101.464837][ T5396] bridge_slave_0: entered promiscuous mode
[ 101.470155][ T5396] bridge0: port 2(bridge_slave_1) entered blocking state
[ 101.473256][ T5396] bridge0: port 2(bridge_slave_1) entered disabled state
[ 101.476836][ T5396] bridge_slave_1: entered allmulticast mode
[ 101.481154][ T5396] bridge_slave_1: entered promiscuous mode
[ 101.505814][ T5396] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 101.511793][ T5396] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 101.536111][ T5396] team0: Port device team_slave_0 added
[ 101.540599][ T5396] team0: Port device team_slave_1 added
[ 101.560790][ T5396] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 101.563830][ T5396] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 101.575130][ T5396] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 101.581701][ T5396] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 101.585906][ T5396] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 101.597285][ T5396] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 101.636014][ T5396] hsr_slave_0: entered promiscuous mode
[ 101.639181][ T5396] hsr_slave_1: entered promiscuous mode
[ 101.876756][ T5396] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 101.896280][ T5396] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 101.909331][ T5396] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 101.925590][ T5396] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 101.954391][ T5396] bridge0: port 2(bridge_slave_1) entered blocking state
[ 101.957643][ T5396] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 101.961577][ T5396] bridge0: port 1(bridge_slave_0) entered blocking state
[ 101.964901][ T5396] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 102.021878][ T5396] 8021q: adding VLAN 0 to HW filter on device bond0
[ 102.048170][ T13] bridge0: port 1(bridge_slave_0) entered disabled state
[ 102.052429][ T13] bridge0: port 2(bridge_slave_1) entered disabled state
[ 102.070087][ T5396] 8021q: adding VLAN 0 to HW filter on device team0
[ 102.090173][ T925] bridge0: port 1(bridge_slave_0) entered blocking state
[ 102.093477][ T925] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 102.110722][ T925] bridge0: port 2(bridge_slave_1) entered blocking state
[ 102.114037][ T925] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 102.178432][ T5396] hsr0: Slave B (hsr_slave_1) is not up; please bring it up to get a fully working HSR network
[ 102.428330][ T5396] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 102.500294][ T5396] veth0_vlan: entered promiscuous mode
[ 102.517479][ T5396] veth1_vlan: entered promiscuous mode
[ 102.561025][ T5396] veth0_macvtap: entered promiscuous mode
[ 102.577107][ T5396] veth1_macvtap: entered promiscuous mode
[ 102.602516][ T5396] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 102.626118][ T5396] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 102.647297][ T2642] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[ 102.656894][ T2642] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[ 102.677082][ T2642] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[ 102.689424][ T2642] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[ 102.892345][ T2642] netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 102.956394][ T2642] netdevsim netdevsim0 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 103.026740][ T2642] netdevsim netdevsim0 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 103.136107][ T2642] netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
2026/01/07 11:13:24 executed programs: 0
[ 104.751420][ T46] Bluetooth: hci0: unexpected cc 0x0c03 length: 249 > 1
[ 104.758077][ T46] Bluetooth: hci0: unexpected cc 0x1003 length: 249 > 9
[ 104.761677][ T46] Bluetooth: hci0: unexpected cc 0x1001 length: 249 > 9
[ 104.765876][ T46] Bluetooth: hci0: unexpected cc 0x0c23 length: 249 > 4
[ 104.769685][ T46] Bluetooth: hci0: unexpected cc 0x0c38 length: 249 > 2
[ 104.912412][ T5436] chnl_net:caif_netlink_parms(): no params data found
[ 105.001561][ T5436] bridge0: port 1(bridge_slave_0) entered blocking state
[ 105.005158][ T5436] bridge0: port 1(bridge_slave_0) entered disabled state
[ 105.008448][ T5436] bridge_slave_0: entered allmulticast mode
[ 105.012249][ T5436] bridge_slave_0: entered promiscuous mode
[ 105.018886][ T5436] bridge0: port 2(bridge_slave_1) entered blocking state
[ 105.022146][ T5436] bridge0: port 2(bridge_slave_1) entered disabled state
[ 105.025711][ T5436] bridge_slave_1: entered allmulticast mode
[ 105.029956][ T5436] bridge_slave_1: entered promiscuous mode
[ 105.053264][ T5436] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 105.059670][ T5436] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 105.108629][ T5436] team0: Port device team_slave_0 added
[ 105.126216][ T5436] team0: Port device team_slave_1 added
[ 105.161624][ T5436] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 105.165010][ T5436] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 105.177590][ T5436] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 105.183670][ T5436] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 105.187495][ T5436] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
[ 105.200266][ T5436] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 105.275262][ T5436] hsr_slave_0: entered promiscuous mode
[ 105.284607][ T5436] hsr_slave_1: entered promiscuous mode
[ 105.292649][ T5436] debugfs: 'hsr0' already exists in 'hsr'
[ 105.296130][ T5436] Cannot create hsr debugfs directory
[ 105.475509][ T2642] bridge_slave_1: left allmulticast mode
[ 105.478241][ T2642] bridge_slave_1: left promiscuous mode
[ 105.481543][ T2642] bridge0: port 2(bridge_slave_1) entered disabled state
[ 105.506238][ T2642] bridge_slave_0: left allmulticast mode
[ 105.508773][ T2642] bridge_slave_0: left promiscuous mode
[ 105.511341][ T2642] bridge0: port 1(bridge_slave_0) entered disabled state
[ 105.886322][ T2642] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
[ 105.892992][ T2642] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
[ 105.905613][ T2642] bond0 (unregistering): Released all slaves
[ 105.999430][ T2642] hsr_slave_0: left promiscuous mode
[ 106.004715][ T2642] hsr_slave_1: left promiscuous mode
[ 106.014745][ T2642] batman_adv: batadv0: Interface deactivated: batadv_slave_0
[ 106.018213][ T2642] batman_adv: batadv0: Removing interface: batadv_slave_0
[ 106.033799][ T2642] batman_adv: batadv0: Interface deactivated: batadv_slave_1
[ 106.038368][ T2642] batman_adv: batadv0: Removing interface: batadv_slave_1
[ 106.061634][ T2642] veth1_macvtap: left promiscuous mode
[ 106.071837][ T2642] veth0_macvtap: left promiscuous mode
[ 106.084326][ T2642] veth1_vlan: left promiscuous mode
[ 106.088805][ T2642] veth0_vlan: left promiscuous mode
[ 106.548267][ T2642] team0 (unregistering): Port device team_slave_1 removed
[ 106.570601][ T2642] team0 (unregistering): Port device team_slave_0 removed
[ 106.855281][ T46] Bluetooth: hci0: command tx timeout
[ 107.536913][ T5436] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 107.568089][ T5436] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 107.587709][ T5436] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 107.611328][ T5436] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 107.796353][ T5436] 8021q: adding VLAN 0 to HW filter on device bond0
[ 107.835009][ T5436] 8021q: adding VLAN 0 to HW filter on device team0
[ 107.848925][ T54] bridge0: port 1(bridge_slave_0) entered blocking state
[ 107.852072][ T54] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 107.879697][ T2642] bridge0: port 2(bridge_slave_1) entered blocking state
[ 107.883224][ T2642] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 108.180796][ T5436] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 108.253047][ T5436] veth0_vlan: entered promiscuous mode
[ 108.274611][ T5436] veth1_vlan: entered promiscuous mode
[ 108.326270][ T5436] veth0_macvtap: entered promiscuous mode
[ 108.337072][ T5436] veth1_macvtap: entered promiscuous mode
[ 108.369184][ T5436] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 108.385640][ T5436] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 108.420449][ T2781] netdevsim netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
[ 108.436622][ T2781] netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
[ 108.443441][ T2781] netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
[ 108.477472][ T2781] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
[ 108.552223][ T13] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 108.569980][ T13] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 108.614658][ T13] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 108.618211][ T13] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
SYZFAIL: failed to recv rpc
fd=3 want=4 recv=0 n=0 (errno 9: Bad file descriptor)
[ 109.867503][ T13] netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 110.876798][ T13] netdevsim netdevsim0 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 111.584719][ T13] netdevsim netdevsim0 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 111.621395][ T13] netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
[ 111.727091][ T13] bridge_slave_1: left allmulticast mode
[ 111.729509][ T13] bridge_slave_1: left promiscuous mode
[ 111.732075][ T13] bridge0: port 2(bridge_slave_1) entered disabled state
[ 111.746340][ T13] bridge_slave_0: left allmulticast mode
[ 111.748648][ T13] bridge_slave_0: left promiscuous mode
[ 111.751051][ T13] bridge0: port 1(bridge_slave_0) entered disabled state
[ 112.145800][ T13] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
[ 112.153209][ T13] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
[ 112.158719][ T13] bond0 (unregistering): Released all slaves
[ 112.365086][ T13] hsr_slave_0: left promiscuous mode
[ 112.384247][ T13] hsr_slave_1: left promiscuous mode
[ 112.387287][ T13] batman_adv: batadv0: Interface deactivated: batadv_slave_0
[ 112.390626][ T13] batman_adv: batadv0: Removing interface: batadv_slave_0
[ 112.407206][ T13] batman_adv: batadv0: Interface deactivated: batadv_slave_1
[ 112.410705][ T13] batman_adv: batadv0: Removing interface: batadv_slave_1
[ 112.432088][ T13] veth1_macvtap: left promiscuous mode
[ 112.446121][ T13] veth0_macvtap: left promiscuous mode
[ 112.448802][ T13] veth1_vlan: left promiscuous mode
[ 112.451149][ T13] veth0_vlan: left promiscuous mode
[ 112.840491][ T13] team0 (unregistering): Port device team_slave_1 removed
[ 112.867103][ T13] team0 (unregistering): Port device team_slave_0 removed
syzkaller build log:
go env (err=<nil>)
AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE='auto'
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/syzkaller/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/syzkaller/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build3375025284=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOMODCACHE='/syzkaller/jobs/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs/linux/gopath'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/syzkaller/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.24.4'
GOWORK=''
PKG_CONFIG='pkg-config'
git status (err=<nil>)
HEAD detached at d1b870e1003b
nothing to commit, working tree clean
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
go list -f '{{.Stale}}' -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d1b870e1003b52891d2196c1e2ee42fe905010ba -X github.com/google/syzkaller/prog.gitRevisionDate=20251128-125159" ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d1b870e1003b52891d2196c1e2ee42fe905010ba -X github.com/google/syzkaller/prog.gitRevisionDate=20251128-125159" ./sys/syz-sysgen
make .descriptions
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
bin/syz-sysgen
touch .descriptions
GOOS=linux GOARCH=amd64 go build -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=d1b870e1003b52891d2196c1e2ee42fe905010ba -X github.com/google/syzkaller/prog.gitRevisionDate=20251128-125159" -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
mkdir -p ./bin/linux_amd64
g++ -o ./bin/linux_amd64/syz-executor executor/executor.cc \
-m64 -O2 -pthread -Wall -Werror -Wparentheses -Wunused-const-variable -Wframe-larger-than=16384 -Wno-stringop-overflow -Wno-array-bounds -Wno-format-overflow -Wno-unused-but-set-variable -Wno-unused-command-line-argument -static-pie -std=c++17 -I. -Iexecutor/_include -DGOOS_linux=1 -DGOARCH_amd64=1 \
-DHOSTGOOS_linux=1 -DGIT_REVISION=\"d1b870e1003b52891d2196c1e2ee42fe905010ba\"
/usr/bin/ld: /tmp/ccX6FRY7.o: in function `Connection::Connect(char const*, char const*)':
executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x104): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
./tools/check-syzos.sh 2>/dev/null
Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=1106ef92580000
Tested on:
commit: 1860d530 f2fs: fix to avoid UAF in f2fs_write_end_io()
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git bugfix/syzbot
kernel config: https://syzkaller.appspot.com/x/.config?x=513255d80ab78f2b
dashboard link: https://syzkaller.appspot.com/bug?extid=b4444e3c972a7a124187
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Note: no patches were applied.
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