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* [syzbot] [block?] general protection fault in blk_update_request
@ 2024-11-02  0:15 syzbot
  2025-12-08  5:49 ` syzbot
                   ` (2 more replies)
  0 siblings, 3 replies; 7+ messages in thread
From: syzbot @ 2024-11-02  0:15 UTC (permalink / raw)
  To: axboe, linux-block, linux-kernel, syzkaller-bugs

Hello,

syzbot found the following issue on:

HEAD commit:    819837584309 Linux 6.12-rc5
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14ec6ca7980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4aec7739e14231a7
dashboard link: https://syzkaller.appspot.com/bug?extid=1d38eedcb25a3b5686a7
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7eaadcc9db59/disk-81983758.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9ffd56091c79/vmlinux-81983758.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c49f66756e3e/bzImage-81983758.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1d38eedcb25a3b5686a7@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xe01ffbf110170c7f: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: maybe wild-memory-access in range [0x00ffff8880b863f8-0x00ffff8880b863ff]
CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:__lock_acquire+0x69/0x2050 kernel/locking/lockdep.c:5065
Code: b6 04 30 84 c0 0f 85 9b 16 00 00 45 31 f6 83 3d c8 e8 ac 0e 00 0f 84 b6 13 00 00 89 54 24 54 89 5c 24 68 4c 89 f8 48 c1 e8 03 <80> 3c 30 00 74 12 4c 89 ff e8 79 48 8e 00 48 be 00 00 00 00 00 fc
RSP: 0018:ffffc90000157610 EFLAGS: 00010013
RAX: 001ffff110170c7f RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 00ffff8880b863fe
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff203a066 R12: ffff88801d2bda00
R13: 0000000000000001 R14: 0000000000000000 R15: 00ffff8880b863fe
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3091aff8 CR3: 000000000e734000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 __queue_work+0x759/0xf50
 queue_work_on+0x1c2/0x380 kernel/workqueue.c:2390
 blk_update_request+0x5e5/0x1160 block/blk-mq.c:923
 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1051
 blk_flush_complete_seq+0x6b7/0xce0 block/blk-flush.c:191
 flush_end_io+0xab1/0xdc0 block/blk-flush.c:250
 __blk_mq_end_request+0x4a5/0x620 block/blk-mq.c:1041
 blk_complete_reqs block/blk-mq.c:1126 [inline]
 blk_done_softirq+0x102/0x150 block/blk-mq.c:1131
 handle_softirqs+0x2c7/0x980 kernel/softirq.c:554
 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927
 smpboot_thread_fn+0x546/0xa30 kernel/smpboot.c:164
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__lock_acquire+0x69/0x2050 kernel/locking/lockdep.c:5065
Code: b6 04 30 84 c0 0f 85 9b 16 00 00 45 31 f6 83 3d c8 e8 ac 0e 00 0f 84 b6 13 00 00 89 54 24 54 89 5c 24 68 4c 89 f8 48 c1 e8 03 <80> 3c 30 00 74 12 4c 89 ff e8 79 48 8e 00 48 be 00 00 00 00 00 fc
RSP: 0018:ffffc90000157610 EFLAGS: 00010013
RAX: 001ffff110170c7f RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 00ffff8880b863fe
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff203a066 R12: ffff88801d2bda00
R13: 0000000000000001 R14: 0000000000000000 R15: 00ffff8880b863fe
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3091aff8 CR3: 000000000e734000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
   0:	b6 04                	mov    $0x4,%dh
   2:	30 84 c0 0f 85 9b 16 	xor    %al,0x169b850f(%rax,%rax,8)
   9:	00 00                	add    %al,(%rax)
   b:	45 31 f6             	xor    %r14d,%r14d
   e:	83 3d c8 e8 ac 0e 00 	cmpl   $0x0,0xeace8c8(%rip)        # 0xeace8dd
  15:	0f 84 b6 13 00 00    	je     0x13d1
  1b:	89 54 24 54          	mov    %edx,0x54(%rsp)
  1f:	89 5c 24 68          	mov    %ebx,0x68(%rsp)
  23:	4c 89 f8             	mov    %r15,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	80 3c 30 00          	cmpb   $0x0,(%rax,%rsi,1) <-- trapping instruction
  2e:	74 12                	je     0x42
  30:	4c 89 ff             	mov    %r15,%rdi
  33:	e8 79 48 8e 00       	call   0x8e48b1
  38:	48                   	rex.W
  39:	be 00 00 00 00       	mov    $0x0,%esi
  3e:	00 fc                	add    %bh,%ah


---
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 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] 7+ messages in thread

* Re: [syzbot] [block?] general protection fault in blk_update_request
  2024-11-02  0:15 [syzbot] [block?] general protection fault in blk_update_request syzbot
@ 2025-12-08  5:49 ` syzbot
  2025-12-09  2:34 ` Jens Axboe
  2025-12-14 12:50 ` [syzbot] [jfs] " syzbot
  2 siblings, 0 replies; 7+ messages in thread
From: syzbot @ 2025-12-08  5:49 UTC (permalink / raw)
  To: axboe, linux-block, linux-kernel, syzkaller-bugs

syzbot has found a reproducer for the following issue on:

HEAD commit:    ba65a4e7120a Merge tag 'clk-for-linus' of git://git.kernel..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10c6aeb4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8750900a7c493a0b
dashboard link: https://syzkaller.appspot.com/bug?extid=1d38eedcb25a3b5686a7
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=1584321a580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0a7549a1a1ed/disk-ba65a4e7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e00dd3537134/vmlinux-ba65a4e7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/30616aa8fe95/bzImage-ba65a4e7.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/9cdaa4551a87/mount_0.gz
  fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=10570a1a580000)
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/cf44fc97da6f/mount_1.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1d38eedcb25a3b5686a7@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in rt_spin_lock+0x88/0x3e0 kernel/locking/spinlock_rt.c:56
Read of size 1 at addr ffff88802d4f0ca8 by task ksoftirqd/0/15

CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 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
 __kasan_check_byte+0x2a/0x40 mm/kasan/common.c:573
 kasan_check_byte include/linux/kasan.h:401 [inline]
 lock_acquire+0x84/0x340 kernel/locking/lockdep.c:5842
 rt_spin_lock+0x88/0x3e0 kernel/locking/spinlock_rt.c:56
 spin_lock include/linux/spinlock_rt.h:44 [inline]
 __wake_up_common_lock+0x2f/0x1e0 kernel/sched/wait.c:124
 blk_update_request+0x57e/0xe60 block/blk-mq.c:1006
 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1168
 blk_complete_reqs block/blk-mq.c:1243 [inline]
 blk_done_softirq+0x10a/0x160 block/blk-mq.c:1248
 handle_softirqs+0x226/0x6d0 kernel/softirq.c:622
 run_ksoftirqd+0xac/0x210 kernel/softirq.c:1063
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Allocated by task 6143:
 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+0x1fb/0x6d0 mm/slub.c:5771
 kmalloc_noprof include/linux/slab.h:957 [inline]
 lbmLogInit fs/jfs/jfs_logmgr.c:1821 [inline]
 lmLogInit+0x3d0/0x19e0 fs/jfs/jfs_logmgr.c:1269
 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
 lmLogOpen+0x4e1/0xfa0 fs/jfs/jfs_logmgr.c:1069
 jfs_mount_rw+0xe9/0x670 fs/jfs/jfs_mount.c:257
 jfs_fill_super+0x754/0xd80 fs/jfs/super.c:532
 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+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6143:
 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:6663 [inline]
 kfree+0x1bd/0x900 mm/slub.c:6871
 lbmLogShutdown fs/jfs/jfs_logmgr.c:1864 [inline]
 lmLogInit+0x1137/0x19e0 fs/jfs/jfs_logmgr.c:1415
 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
 lmLogOpen+0x4e1/0xfa0 fs/jfs/jfs_logmgr.c:1069
 jfs_mount_rw+0xe9/0x670 fs/jfs/jfs_mount.c:257
 jfs_fill_super+0x754/0xd80 fs/jfs/super.c:532
 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+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802d4f0c00
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 168 bytes inside of
 freed 256-byte region [ffff88802d4f0c00, ffff88802d4f0d00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2d4f0
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff88813ff26b40 ffffea00009c2900 dead000000000004
raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 0080000000000040 ffff88813ff26b40 ffffea00009c2900 dead000000000004
head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 0080000000000001 ffffea0000b53c01 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 16081569570, free_ts 0
 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+0x28c0/0x2960 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_pages_mpol+0xd1/0x380 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+0xb10/0x1400 mm/slub.c:4651
 __slab_alloc+0xc6/0x1f0 mm/slub.c:4774
 __slab_alloc_node mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:5246 [inline]
 __do_kmalloc_node mm/slub.c:5651 [inline]
 __kvmalloc_node_noprof+0x327/0x940 mm/slub.c:7129
 v4l2_ctrl_new+0x9d5/0x1790 drivers/media/v4l2-core/v4l2-ctrls-core.c:2112
 v4l2_ctrl_new_std+0x24d/0x2f0 drivers/media/v4l2-core/v4l2-ctrls-core.c:2266
 handler_new_ref+0x153/0x9c0 drivers/media/v4l2-core/v4l2-ctrls-core.c:1853
 v4l2_ctrl_add_handler+0x19f/0x290 drivers/media/v4l2-core/v4l2-ctrls-core.c:2416
 vivid_create_controls+0x2f57/0x3a60 drivers/media/test-drivers/vivid/vivid-ctrls.c:2051
 vivid_create_instance drivers/media/test-drivers/vivid/vivid-core.c:1933 [inline]
 vivid_probe+0x41b5/0x7150 drivers/media/test-drivers/vivid/vivid-core.c:2095
 platform_probe+0xf9/0x190 drivers/base/platform.c:1446
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x26d/0xad0 drivers/base/dd.c:659
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802d4f0b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802d4f0c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802d4f0c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88802d4f0d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802d4f0d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
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.

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [syzbot] [block?] general protection fault in blk_update_request
  2024-11-02  0:15 [syzbot] [block?] general protection fault in blk_update_request syzbot
  2025-12-08  5:49 ` syzbot
@ 2025-12-09  2:34 ` Jens Axboe
  2025-12-14 12:50 ` [syzbot] [jfs] " syzbot
  2 siblings, 0 replies; 7+ messages in thread
From: Jens Axboe @ 2025-12-09  2:34 UTC (permalink / raw)
  To: syzbot, linux-block, linux-kernel, syzkaller-bugs

#syz set subsystems: jfs

-- 
Jens Axboe


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [syzbot] [jfs] general protection fault in blk_update_request
  2024-11-02  0:15 [syzbot] [block?] general protection fault in blk_update_request syzbot
  2025-12-08  5:49 ` syzbot
  2025-12-09  2:34 ` Jens Axboe
@ 2025-12-14 12:50 ` syzbot
  2025-12-16  3:23   ` [PATCH] jfs: Extend the done of the window period Edward Adam Davis
  2 siblings, 1 reply; 7+ messages in thread
From: syzbot @ 2025-12-14 12:50 UTC (permalink / raw)
  To: axboe, jfs-discussion, linux-block, linux-kernel, shaggy,
	syzkaller-bugs

syzbot has found a reproducer for the following issue on:

HEAD commit:    8f0b4cce4481 Linux 6.19-rc1
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12b5911a580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1f2b6fe1fdf1a00b
dashboard link: https://syzkaller.appspot.com/bug?extid=1d38eedcb25a3b5686a7
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=133919c2580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13da09b4580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ea3b19e4d883/disk-8f0b4cce.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bd7c115820ba/vmlinux-8f0b4cce.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e5813cc1963f/bzImage-8f0b4cce.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/c0e5f2b9d745/mount_0.gz
  fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=153919c2580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1d38eedcb25a3b5686a7@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in rt_spin_lock+0x88/0x3e0 kernel/locking/spinlock_rt.c:56
Read of size 1 at addr ffff888038671ca8 by task ksoftirqd/0/15

CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trac[  124.734676][    C0] Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 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
 __kasan_check_byte+0x2a/0x40 mm/kasan/common.c:573
 kasan_check_byte include/linux/kasan.h:401 [inline]
 lock_acquire+0x84/0x340 kernel/locking/lockdep.c:5842
 rt_spin_lock+0x88/0x3e0 kernel/locking/spinlock_rt.c:56
 spin_lock include/linux/spinlock_rt.h:44 [inline]
 __wake_up_common_lock+0x2f/0x1e0 kernel/sched/wait.c:124
 blk_update_request+0x57e/0xe60 block/blk-mq.c:1007
 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1169
 blk_complete_reqs block/blk-mq.c:1244 [inline]
 blk_done_softirq+0x10a/0x160 block/blk-mq.c:1249
 handle_softirqs+0x226/0x6d0 kernel/softirq.c:622
 run_ksoftirqd+0xac/0x210 kernel/softirq.c:1063
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Allocated by task 6101:
 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+0x1fb/0x6d0 mm/slub.c:5776
 kmalloc_noprof include/linux/slab.h:957 [inline]
 lbmLogInit fs/jfs/jfs_logmgr.c:1821 [inline]
 lmLogInit+0x3d0/0x19e0 fs/jfs/jfs_logmgr.c:1269
 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
 lmLogOpen+0x4e1/0xfa0 fs/jfs/jfs_logmgr.c:1069
 jfs_mount_rw+0xe9/0x670 fs/jfs/jfs_mount.c:257
 jfs_fill_super+0x754/0xd80 fs/jfs/super.c:532
 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+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6101:
 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:6668 [inline]
 kfree+0x1bd/0x900 mm/slub.c:6876
 lbmLogShutdown fs/jfs/jfs_logmgr.c:1864 [inline]
 lmLogInit+0x1137/0x19e0 fs/jfs/jfs_logmgr.c:1415
 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
 lmLogOpen+0x4e1/0xfa0 fs/jfs/jfs_logmgr.c:1069
 jfs_mount_rw+0xe9/0x670 fs/jfs/jfs_mount.c:257
 jfs_fill_super+0x754/0xd80 fs/jfs/super.c:532
 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+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888038671c00
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 168 bytes inside of
 freed 256-byte region [ffff888038671c00, ffff888038671d00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x38670
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff88813ff26b40 ffffea0000e13f00 dead000000000002
raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 0080000000000040 ffff88813ff26b40 ffffea0000e13f00 dead000000000002
head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 0080000000000001 ffffea0000e19c01 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 5883, tgid 5883 (syz-executor), ts 92687559576, free_ts 92184229989
 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+0x28c0/0x2960 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_slab_page mm/slub.c:3077 [inline]
 allocate_slab+0x7a/0x3b0 mm/slub.c:3248
 new_slab mm/slub.c:3302 [inline]
 ___slab_alloc+0xb10/0x1400 mm/slub.c:4656
 __slab_alloc+0xc6/0x1f0 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]
 __kmalloc_node_noprof+0x2c4/0x820 mm/slub.c:5663
 kmalloc_array_node_noprof include/linux/slab.h:1075 [inline]
 alloc_slab_obj_exts+0x3e/0x100 mm/slub.c:2123
 account_slab mm/slub.c:3202 [inline]
 allocate_slab+0x1cc/0x3b0 mm/slub.c:3267
 new_slab mm/slub.c:3302 [inline]
 ___slab_alloc+0xb10/0x1400 mm/slub.c:4656
 __slab_alloc+0xc6/0x1f0 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+0x327/0x940 mm/slub.c:7134
 allocate_hook_entries_size net/netfilter/core.c:58 [inline]
 nf_hook_entries_grow+0x281/0x720 net/netfilter/core.c:137
 __nf_register_net_hook+0x2c9/0x930 net/netfilter/core.c:432
 nf_register_net_hook+0xb2/0x190 net/netfilter/core.c:575
 nf_register_net_hooks+0x44/0x1b0 net/netfilter/core.c:591
page last free pid 5173 tgid 5173 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xfe1/0x1170 mm/page_alloc.c:2943
 discard_slab mm/slub.c:3346 [inline]
 __put_partials+0x149/0x170 mm/slub.c:3886
 __slab_free+0x139/0x210 mm/slub.c:5952
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 __do_kmalloc_node mm/slub.c:5656 [inline]
 __kmalloc_noprof+0x1ec/0x7e0 mm/slub.c:5669
 kmalloc_noprof include/linux/slab.h:961 [inline]
 tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:822
 security_inode_getattr+0x12f/0x330 security/security.c:1869
 vfs_getattr fs/stat.c:259 [inline]
 vfs_fstat fs/stat.c:281 [inline]
 __do_sys_newfstat fs/stat.c:555 [inline]
 __se_sys_newfstat fs/stat.c:550 [inline]
 __x64_sys_newfstat+0xfc/0x200 fs/stat.c:550
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888038671b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888038671c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888038671c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888038671d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888038671d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
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.

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [PATCH] jfs: Extend the done of the window period
  2025-12-14 12:50 ` [syzbot] [jfs] " syzbot
@ 2025-12-16  3:23   ` Edward Adam Davis
  2025-12-16 13:27     ` [syzbot ci] " syzbot ci
  0 siblings, 1 reply; 7+ messages in thread
From: Edward Adam Davis @ 2025-12-16  3:23 UTC (permalink / raw)
  To: syzbot+1d38eedcb25a3b5686a7
  Cc: axboe, jfs-discussion, linux-block, linux-kernel, shaggy,
	syzkaller-bugs

In lbmRead(), the I/O event waited for by wait_event() finishes before
it goes to sleep, and the lbmIODone() prematurely sets the flag to
lbmDONE, thus ending the wait. This causes wait_event() to return before
lbmREAD is cleared (because lbmDONE was set first), the premature return
of wait_event() leads to the release of lbuf before lbmIODone() returns,
thus triggering the use-after-free vulnerability reported in [1].

Moving the operation of setting the lbmDONE flag to after clearing lbmREAD
in lbmIODone() avoids the use-after-free vulnerability reported in [1].

[1]
BUG: KASAN: slab-use-after-free in rt_spin_lock+0x88/0x3e0 kernel/locking/spinlock_rt.c:56
Call Trace:
 blk_update_request+0x57e/0xe60 block/blk-mq.c:1007
 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1169
 blk_complete_reqs block/blk-mq.c:1244 [inline]
 blk_done_softirq+0x10a/0x160 block/blk-mq.c:1249

Allocated by task 6101:
 lbmLogInit fs/jfs/jfs_logmgr.c:1821 [inline]
 lmLogInit+0x3d0/0x19e0 fs/jfs/jfs_logmgr.c:1269
 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
 lmLogOpen+0x4e1/0xfa0 fs/jfs/jfs_logmgr.c:1069
 jfs_mount_rw+0xe9/0x670 fs/jfs/jfs_mount.c:257
 jfs_fill_super+0x754/0xd80 fs/jfs/super.c:532

Freed by task 6101:
 kfree+0x1bd/0x900 mm/slub.c:6876
 lbmLogShutdown fs/jfs/jfs_logmgr.c:1864 [inline]
 lmLogInit+0x1137/0x19e0 fs/jfs/jfs_logmgr.c:1415
 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
 lmLogOpen+0x4e1/0xfa0 fs/jfs/jfs_logmgr.c:1069
 jfs_mount_rw+0xe9/0x670 fs/jfs/jfs_mount.c:257
 jfs_fill_super+0x754/0xd80 fs/jfs/super.c:532

Reported-by: syzbot+1d38eedcb25a3b5686a7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=1d38eedcb25a3b5686a7
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
 fs/jfs/jfs_logmgr.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index b343c5ea1159..dda9ffa8eaf5 100644
--- a/fs/jfs/jfs_logmgr.c
+++ b/fs/jfs/jfs_logmgr.c
@@ -2180,8 +2180,6 @@ static void lbmIODone(struct bio *bio)
 
 	LCACHE_LOCK(flags);		/* disable+lock */
 
-	bp->l_flag |= lbmDONE;
-
 	if (bio->bi_status) {
 		bp->l_flag |= lbmERROR;
 
@@ -2196,12 +2194,10 @@ static void lbmIODone(struct bio *bio)
 	if (bp->l_flag & lbmREAD) {
 		bp->l_flag &= ~lbmREAD;
 
-		LCACHE_UNLOCK(flags);	/* unlock+enable */
-
 		/* wakeup I/O initiator */
 		LCACHE_WAKEUP(&bp->l_ioevent);
 
-		return;
+		goto out;
 	}
 
 	/*
@@ -2225,8 +2221,7 @@ static void lbmIODone(struct bio *bio)
 
 	if (bp->l_flag & lbmDIRECT) {
 		LCACHE_WAKEUP(&bp->l_ioevent);
-		LCACHE_UNLOCK(flags);
-		return;
+		goto out;
 	}
 
 	tail = log->wqueue;
@@ -2278,8 +2273,6 @@ static void lbmIODone(struct bio *bio)
 	 * leave buffer for i/o initiator to dispose
 	 */
 	if (bp->l_flag & lbmSYNC) {
-		LCACHE_UNLOCK(flags);	/* unlock+enable */
-
 		/* wakeup I/O initiator */
 		LCACHE_WAKEUP(&bp->l_ioevent);
 	}
@@ -2288,7 +2281,6 @@ static void lbmIODone(struct bio *bio)
 	 *	Group Commit pageout:
 	 */
 	else if (bp->l_flag & lbmGC) {
-		LCACHE_UNLOCK(flags);
 		lmPostGC(bp);
 	}
 
@@ -2302,9 +2294,11 @@ static void lbmIODone(struct bio *bio)
 		assert(bp->l_flag & lbmRELEASE);
 		assert(bp->l_flag & lbmFREE);
 		lbmfree(bp);
-
-		LCACHE_UNLOCK(flags);	/* unlock+enable */
 	}
+
+out:
+	bp->l_flag |= lbmDONE;
+	LCACHE_UNLOCK(flags);
 }
 
 int jfsIOWait(void *arg)
-- 
2.43.0


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* [syzbot ci] Re: jfs: Extend the done of the window period
  2025-12-16  3:23   ` [PATCH] jfs: Extend the done of the window period Edward Adam Davis
@ 2025-12-16 13:27     ` syzbot ci
  2025-12-16 13:57       ` [PATCH v2] " Edward Adam Davis
  0 siblings, 1 reply; 7+ messages in thread
From: syzbot ci @ 2025-12-16 13:27 UTC (permalink / raw)
  To: axboe, eadavis, jfs-discussion, linux-block, linux-kernel, shaggy,
	syzbot, syzkaller-bugs
  Cc: syzbot, syzkaller-bugs

syzbot ci has tested the following series

[v1] jfs: Extend the done of the window period
https://lore.kernel.org/all/tencent_2AC2ECAACC587B4E6C342D096F909424E90A@qq.com
* [PATCH] jfs: Extend the done of the window period

and found the following issue:
possible deadlock in lbmIODone

Full report is available here:
https://ci.syzbot.org/series/49387e77-608d-493c-9978-8d1e9ab79507

***

possible deadlock in lbmIODone

tree:      torvalds
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
base:      d358e5254674b70f34c847715ca509e46eb81e6f
arch:      amd64
compiler:  Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
config:    https://ci.syzbot.org/builds/802e00bf-1926-4ea9-a853-4f01d10a4a6e/config
C repro:   https://ci.syzbot.org/findings/784b824b-3582-4c98-a807-ff28792ecaac/c_repro
syz repro: https://ci.syzbot.org/findings/784b824b-3582-4c98-a807-ff28792ecaac/syz_repro

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
ksoftirqd/0/15 is trying to acquire lock:
ffff888112c1f9e8 (&(log)->gclock){..-.}-{3:3}, at: lmPostGC fs/jfs/jfs_logmgr.c:810 [inline]
ffff888112c1f9e8 (&(log)->gclock){..-.}-{3:3}, at: lbmIODone+0x681/0x17b0 fs/jfs/jfs_logmgr.c:2284

but task is already holding lock:
ffffffff8e396158 (jfsLCacheLock){..-.}-{3:3}, at: lbmIODone+0x92/0x17b0 fs/jfs/jfs_logmgr.c:2181

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (jfsLCacheLock){..-.}-{3:3}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
       lbmWrite+0x115/0x490 fs/jfs/jfs_logmgr.c:2022
       lmGCwrite fs/jfs/jfs_logmgr.c:-1 [inline]
       lmGroupCommit+0x570/0xb30 fs/jfs/jfs_logmgr.c:687
       txCommit+0x4940/0x5430 fs/jfs/jfs_txnmgr.c:1305
       diNewIAG fs/jfs/jfs_imap.c:2592 [inline]
       diAllocExt fs/jfs/jfs_imap.c:1905 [inline]
       diAllocAG+0x1770/0x1df0 fs/jfs/jfs_imap.c:1669
       diAlloc+0x1d5/0x1680 fs/jfs/jfs_imap.c:1590
       ialloc+0x8c/0x8f0 fs/jfs/jfs_inode.c:56
       jfs_mkdir+0x193/0xa70 fs/jfs/namei.c:225
       vfs_mkdir+0x512/0x5b0 fs/namei.c:5130
       do_mkdirat+0x276/0x4b0 fs/namei.c:5164
       __do_sys_mkdirat fs/namei.c:5186 [inline]
       __se_sys_mkdirat fs/namei.c:5184 [inline]
       __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5184
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&(log)->gclock){..-.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
       lmPostGC fs/jfs/jfs_logmgr.c:810 [inline]
       lbmIODone+0x681/0x17b0 fs/jfs/jfs_logmgr.c:2284
       blk_update_request+0x57e/0xe60 block/blk-mq.c:1007
       blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1169
       blk_complete_reqs block/blk-mq.c:1244 [inline]
       blk_done_softirq+0x10a/0x160 block/blk-mq.c:1249
       handle_softirqs+0x27d/0x850 kernel/softirq.c:622
       run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063
       smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
       kthread+0x711/0x8a0 kernel/kthread.c:463
       ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(jfsLCacheLock);
                               lock(&(log)->gclock);
                               lock(jfsLCacheLock);
  lock(&(log)->gclock);

 *** DEADLOCK ***

1 lock held by ksoftirqd/0/15:
 #0: ffffffff8e396158 (jfsLCacheLock){..-.}-{3:3}, at: lbmIODone+0x92/0x17b0 fs/jfs/jfs_logmgr.c:2181

stack backtrace:
CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
 lmPostGC fs/jfs/jfs_logmgr.c:810 [inline]
 lbmIODone+0x681/0x17b0 fs/jfs/jfs_logmgr.c:2284
 blk_update_request+0x57e/0xe60 block/blk-mq.c:1007
 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1169
 blk_complete_reqs block/blk-mq.c:1244 [inline]
 blk_done_softirq+0x10a/0x160 block/blk-mq.c:1249
 handle_softirqs+0x27d/0x850 kernel/softirq.c:622
 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
  Tested-by: syzbot@syzkaller.appspotmail.com

---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [PATCH v2] jfs: Extend the done of the window period
  2025-12-16 13:27     ` [syzbot ci] " syzbot ci
@ 2025-12-16 13:57       ` Edward Adam Davis
  0 siblings, 0 replies; 7+ messages in thread
From: Edward Adam Davis @ 2025-12-16 13:57 UTC (permalink / raw)
  To: syzbot+ci1f1a4e9c887bc6ea
  Cc: axboe, eadavis, jfs-discussion, linux-block, linux-kernel, shaggy,
	syzbot, syzbot, syzkaller-bugs

In lbmRead(), the I/O event waited for by wait_event() finishes before
it goes to sleep, and the lbmIODone() prematurely sets the flag to
lbmDONE, thus ending the wait. This causes wait_event() to return before
lbmREAD is cleared (because lbmDONE was set first), the premature return
of wait_event() leads to the release of lbuf before lbmIODone() returns,
thus triggering the use-after-free vulnerability reported in [1].

Moving the operation of setting the lbmDONE flag to after clearing lbmREAD
in lbmIODone() avoids the use-after-free vulnerability reported in [1].

[1]
BUG: KASAN: slab-use-after-free in rt_spin_lock+0x88/0x3e0 kernel/locking/spinlock_rt.c:56
Call Trace:
 blk_update_request+0x57e/0xe60 block/blk-mq.c:1007
 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1169
 blk_complete_reqs block/blk-mq.c:1244 [inline]
 blk_done_softirq+0x10a/0x160 block/blk-mq.c:1249

Allocated by task 6101:
 lbmLogInit fs/jfs/jfs_logmgr.c:1821 [inline]
 lmLogInit+0x3d0/0x19e0 fs/jfs/jfs_logmgr.c:1269
 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
 lmLogOpen+0x4e1/0xfa0 fs/jfs/jfs_logmgr.c:1069
 jfs_mount_rw+0xe9/0x670 fs/jfs/jfs_mount.c:257
 jfs_fill_super+0x754/0xd80 fs/jfs/super.c:532

Freed by task 6101:
 kfree+0x1bd/0x900 mm/slub.c:6876
 lbmLogShutdown fs/jfs/jfs_logmgr.c:1864 [inline]
 lmLogInit+0x1137/0x19e0 fs/jfs/jfs_logmgr.c:1415
 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
 lmLogOpen+0x4e1/0xfa0 fs/jfs/jfs_logmgr.c:1069
 jfs_mount_rw+0xe9/0x670 fs/jfs/jfs_mount.c:257
 jfs_fill_super+0x754/0xd80 fs/jfs/super.c:532

Reported-by: syzbot+1d38eedcb25a3b5686a7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=1d38eedcb25a3b5686a7
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
v1 -> v2: fix potential deadlock

 fs/jfs/jfs_logmgr.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index b343c5ea1159..0db4bc9f2d6c 100644
--- a/fs/jfs/jfs_logmgr.c
+++ b/fs/jfs/jfs_logmgr.c
@@ -2180,8 +2180,6 @@ static void lbmIODone(struct bio *bio)
 
 	LCACHE_LOCK(flags);		/* disable+lock */
 
-	bp->l_flag |= lbmDONE;
-
 	if (bio->bi_status) {
 		bp->l_flag |= lbmERROR;
 
@@ -2196,12 +2194,10 @@ static void lbmIODone(struct bio *bio)
 	if (bp->l_flag & lbmREAD) {
 		bp->l_flag &= ~lbmREAD;
 
-		LCACHE_UNLOCK(flags);	/* unlock+enable */
-
 		/* wakeup I/O initiator */
 		LCACHE_WAKEUP(&bp->l_ioevent);
 
-		return;
+		goto out;
 	}
 
 	/*
@@ -2225,8 +2221,7 @@ static void lbmIODone(struct bio *bio)
 
 	if (bp->l_flag & lbmDIRECT) {
 		LCACHE_WAKEUP(&bp->l_ioevent);
-		LCACHE_UNLOCK(flags);
-		return;
+		goto out;
 	}
 
 	tail = log->wqueue;
@@ -2278,8 +2273,6 @@ static void lbmIODone(struct bio *bio)
 	 * leave buffer for i/o initiator to dispose
 	 */
 	if (bp->l_flag & lbmSYNC) {
-		LCACHE_UNLOCK(flags);	/* unlock+enable */
-
 		/* wakeup I/O initiator */
 		LCACHE_WAKEUP(&bp->l_ioevent);
 	}
@@ -2290,6 +2283,7 @@ static void lbmIODone(struct bio *bio)
 	else if (bp->l_flag & lbmGC) {
 		LCACHE_UNLOCK(flags);
 		lmPostGC(bp);
+		LCACHE_LOCK(flags);		/* disable+lock */
 	}
 
 	/*
@@ -2302,9 +2296,11 @@ static void lbmIODone(struct bio *bio)
 		assert(bp->l_flag & lbmRELEASE);
 		assert(bp->l_flag & lbmFREE);
 		lbmfree(bp);
-
-		LCACHE_UNLOCK(flags);	/* unlock+enable */
 	}
+
+out:
+	bp->l_flag |= lbmDONE;
+	LCACHE_UNLOCK(flags);
 }
 
 int jfsIOWait(void *arg)
-- 
2.43.0


^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2025-12-16 13:57 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-11-02  0:15 [syzbot] [block?] general protection fault in blk_update_request syzbot
2025-12-08  5:49 ` syzbot
2025-12-09  2:34 ` Jens Axboe
2025-12-14 12:50 ` [syzbot] [jfs] " syzbot
2025-12-16  3:23   ` [PATCH] jfs: Extend the done of the window period Edward Adam Davis
2025-12-16 13:27     ` [syzbot ci] " syzbot ci
2025-12-16 13:57       ` [PATCH v2] " Edward Adam Davis

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