Re: [syzbot] [net?] KASAN: slab-use-after-free Read in handle_tx (2)

syzbot
2025-01-14T01:26:24Z

syzbot has found a reproducer for the following issue on:

HEAD commit: c45323b7560e Merge tag 'mm-hotfixes-stable-2025-01-13-00-0..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10565cb0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=d1cb4a1f148c0861
dashboard link: https://syzkaller.appspot.com/bug?extid=827272712bd6d12c79a4
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14565cb0580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-c45323b7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d162460a6713/vmlinux-c45323b7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f905e34cb8b4/bzImage-c45323b7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+827272712bd6d12c79a4@syzkaller.appspotmail.com

ieee802154 phy0 wpan0: encryption failed: -22
ieee802154 phy1 wpan1: encryption failed: -22
==================================================================
BUG: KASAN: slab-use-after-free in handle_tx+0x5a5/0x630 drivers/net/caif/caif_serial.c:236
Read of size 8 at addr ffff88804b550020 by task aoe_tx0/1417

CPU: 2 UID: 0 PID: 1417 Comm: aoe_tx0 Not tainted 6.13.0-rc7-syzkaller-00019-gc45323b7560e #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xc3/0x620 mm/kasan/report.c:489
kasan_report+0xd9/0x110 mm/kasan/report.c:602
handle_tx+0x5a5/0x630 drivers/net/caif/caif_serial.c:236
__netdev_start_xmit include/linux/netdevice.h:5002 [inline]
netdev_start_xmit include/linux/netdevice.h:5011 [inline]
xmit_one net/core/dev.c:3620 [inline]
dev_hard_start_xmit+0x9a/0x7b0 net/core/dev.c:3636
__dev_queue_xmit+0x7f0/0x43e0 net/core/dev.c:4466
dev_queue_xmit include/linux/netdevice.h:3168 [inline]
tx+0xcc/0x190 drivers/block/aoe/aoenet.c:62
kthread+0x1e7/0x3c0 drivers/block/aoe/aoecmd.c:1237
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>

Allocated by task 6243:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
kmalloc_noprof include/linux/slab.h:901 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
alloc_tty_struct+0x98/0x8d0 drivers/tty/tty_io.c:3116
tty_init_dev.part.0+0x1e/0x660 drivers/tty/tty_io.c:1409
tty_init_dev include/linux/err.h:67 [inline]
tty_open_by_driver drivers/tty/tty_io.c:2082 [inline]
tty_open+0xac1/0xf80 drivers/tty/tty_io.c:2129
chrdev_open+0x237/0x6a0 fs/char_dev.c:414
do_dentry_open+0xf59/0x1ea0 fs/open.c:945
vfs_open+0x82/0x3f0 fs/open.c:1075
do_open fs/namei.c:3828 [inline]
path_openat+0x1e6a/0x2d60 fs/namei.c:3987
do_filp_open+0x20c/0x470 fs/namei.c:4014
do_sys_openat2+0x17a/0x1e0 fs/open.c:1402
do_sys_open fs/open.c:1417 [inline]
__do_sys_openat fs/open.c:1433 [inline]
__se_sys_openat fs/open.c:1428 [inline]
__x64_sys_openat+0x175/0x210 fs/open.c:1428
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 9:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2353 [inline]
slab_free mm/slub.c:4613 [inline]
kfree+0x14f/0x4b0 mm/slub.c:4761
process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3317 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Last potentially related work creation:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
__kasan_record_aux_stack+0xba/0xd0 mm/kasan/generic.c:544
insert_work+0x36/0x230 kernel/workqueue.c:2183
__queue_work+0x97e/0x1080 kernel/workqueue.c:2339
queue_work_on+0x11a/0x140 kernel/workqueue.c:2390
kref_put include/linux/kref.h:65 [inline]
tty_kref_put drivers/tty/tty_io.c:1566 [inline]
tty_kref_put drivers/tty/tty_io.c:1563 [inline]
release_tty+0x4de/0x5d0 drivers/tty/tty_io.c:1602
tty_release_struct+0xb7/0xe0 drivers/tty/tty_io.c:1701
tty_release+0xe25/0x1410 drivers/tty/tty_io.c:1861
__fput+0x3f8/0xb60 fs/file_table.c:450
task_work_run+0x14e/0x250 kernel/task_work.c:239
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88804b550000
which belongs to the cache kmalloc-cg-2k of size 2048
The buggy address is located 32 bytes inside of
freed 2048-byte region [ffff88804b550000, ffff88804b550800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88804b554000 pfn:0x4b550
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8880247d5b81
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88801b050140 ffffea0000d3b210 ffff88801b04e708
raw: ffff88804b554000 0000000000080005 00000001f5000000 ffff8880247d5b81
head: 00fff00000000240 ffff88801b050140 ffffea0000d3b210 ffff88801b04e708
head: ffff88804b554000 0000000000080005 00000001f5000000 ffff8880247d5b81
head: 00fff00000000003 ffffea00012d5401 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6034, tgid 6034 (syz-executor), ts 81856364049, free_ts 80251618977
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1558
prep_new_page mm/page_alloc.c:1566 [inline]
get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3476
__alloc_pages_noprof+0x223/0x25b0 mm/page_alloc.c:4753
alloc_pages_mpol_noprof+0x2c8/0x620 mm/mempolicy.c:2269
alloc_slab_page mm/slub.c:2423 [inline]
allocate_slab mm/slub.c:2589 [inline]
new_slab+0x2c9/0x410 mm/slub.c:2642
___slab_alloc+0xd7d/0x17a0 mm/slub.c:3830
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3920
__slab_alloc_node mm/slub.c:3995 [inline]
slab_alloc_node mm/slub.c:4156 [inline]
__do_kmalloc_node mm/slub.c:4297 [inline]
__kmalloc_noprof+0x2ec/0x510 mm/slub.c:4310
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
__register_sysctl_table+0xb4/0x1910 fs/proc/proc_sysctl.c:1375
__devinet_sysctl_register+0x1b5/0x360 net/ipv4/devinet.c:2630
devinet_sysctl_register net/ipv4/devinet.c:2670 [inline]
devinet_sysctl_register+0x17b/0x200 net/ipv4/devinet.c:2660
inetdev_init+0x2b8/0x5a0 net/ipv4/devinet.c:299
inetdev_event+0xc61/0x18a0 net/ipv4/devinet.c:1598
notifier_call_chain+0xb7/0x410 kernel/notifier.c:85
call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2026
call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
call_netdevice_notifiers net/core/dev.c:2078 [inline]
register_netdevice+0x17a0/0x1e90 net/core/dev.c:10651
page last free pid 5917 tgid 5917 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1127 [inline]
free_unref_page+0x661/0x1080 mm/page_alloc.c:2659
kasan_depopulate_vmalloc_pte+0x63/0x80 mm/kasan/shadow.c:408
apply_to_pte_range mm/memory.c:2831 [inline]
apply_to_pmd_range mm/memory.c:2875 [inline]
apply_to_pud_range mm/memory.c:2911 [inline]
apply_to_p4d_range mm/memory.c:2947 [inline]
__apply_to_page_range+0x5fd/0xd30 mm/memory.c:2981
kasan_release_vmalloc+0xd1/0xe0 mm/kasan/shadow.c:529
kasan_release_vmalloc_node mm/vmalloc.c:2196 [inline]
purge_vmap_node+0x1d1/0xa40 mm/vmalloc.c:2213
__purge_vmap_area_lazy+0x9bf/0xc10 mm/vmalloc.c:2304
drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2338
process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3317 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
ffff88804b54ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88804b54ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88804b550000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88804b550080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88804b550100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

---
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