syzbot


KASAN: slab-use-after-free Read in lbmIODone

Status: upstream: reported C repro on 2025/09/29 13:20
Subsystems: jfs
[Documentation on labels]
Reported-by: syzbot+ecf51a7ccb6b1394e90c@syzkaller.appspotmail.com
First crash: 204d, last: now
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
f9a8fa2f-c45a-4c7b-a5fd-b897e02c7691 repro KASAN: slab-use-after-free Read in lbmIODone 2026/03/07 07:40 2026/03/07 07:40 2026/03/07 07:50 31e9c887f7dc24e04b3ca70d0d54fc34141844b0
Cause bisection: failed (error log, bisect log)
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [jfs?] KASAN: slab-use-after-free Read in lbmIODone 0 (3) 2026/04/15 09:06
Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in lbmIODone (2) jfs 19 syz 117 665d 1142d 0/29 auto-obsoleted due to no activity on 2024/08/29 23:10
linux-5.15 KASAN: use-after-free Read in lbmIODone (4) 19 1 223d 223d 0/3 auto-obsoleted due to no activity on 2025/12/14 20:18
linux-5.15 KASAN: use-after-free Read in lbmIODone (3) 19 1 340d 340d 0/3 auto-obsoleted due to no activity on 2025/08/20 03:33
linux-4.19 KASAN: use-after-free Read in lbmIODone jfs 19 C 150 1158d 2002d 0/1 upstream: reported C repro on 2020/10/22 09:37
linux-6.1 KASAN: use-after-free Read in lbmIODone 19 1 740d 740d 0/3 auto-obsoleted due to no activity on 2024/07/15 22:58
upstream KASAN: use-after-free Read in lbmIODone jfs 19 syz inconclusive unreliable 20 1494d 2033d 0/29 auto-obsoleted due to no activity on 2023/01/13 19:58
linux-5.15 KASAN: use-after-free Read in lbmIODone (2) 19 1 476d 476d 0/3 auto-obsoleted due to no activity on 2025/04/06 05:07
linux-4.14 KASAN: use-after-free Read in lbmIODone jfs 19 C 68 1159d 2032d 0/1 upstream: reported C repro on 2020/09/23 00:55
linux-5.15 KASAN: use-after-free Read in lbmIODone 19 1 702d 702d 0/3 auto-obsoleted due to no activity on 2024/08/22 10:14

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in lbmIODone+0x1312/0x16c0 fs/jfs/jfs_logmgr.c:2192
Read of size 4 at addr ffff888029052c08 by task rcuc/0/20

CPU: 0 UID: 0 PID: 20 Comm: rcuc/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 lbmIODone+0x1312/0x16c0 fs/jfs/jfs_logmgr.c:2192
 blk_update_request+0x57e/0xe60 block/blk-mq.c:1016
 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1178
 blk_complete_reqs block/blk-mq.c:1253 [inline]
 blk_done_softirq+0x10a/0x160 block/blk-mq.c:1258
 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 __local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_do_batch kernel/rcu/tree.c:2636 [inline]
 rcu_core kernel/rcu/tree.c:2869 [inline]
 rcu_cpu_kthread+0x9e8/0x1470 kernel/rcu/tree.c:2957
 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 6108:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x3a6/0x690 mm/slub.c:5415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 lbmLogInit fs/jfs/jfs_logmgr.c:1819 [inline]
 lmLogInit+0x3e5/0x1a00 fs/jfs/jfs_logmgr.c:1267
 open_inline_log fs/jfs/jfs_logmgr.c:1173 [inline]
 lmLogOpen+0x4e1/0xfa0 fs/jfs/jfs_logmgr.c:1067
 jfs_mount_rw+0xee/0x670 fs/jfs/jfs_mount.c:257
 jfs_fill_super+0x754/0xd80 fs/jfs/super.c:532
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3758 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3834
 do_mount fs/namespace.c:4167 [inline]
 __do_sys_mount fs/namespace.c:4383 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4360
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5920:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6246 [inline]
 kfree+0x1c5/0x6c0 mm/slub.c:6561
 lbmLogShutdown fs/jfs/jfs_logmgr.c:1862 [inline]
 lmLogShutdown+0x456/0x850 fs/jfs/jfs_logmgr.c:1681
 lmLogClose+0x28a/0x520 fs/jfs/jfs_logmgr.c:1457
 jfs_umount+0x2fb/0x3d0 fs/jfs/jfs_umount.c:124
 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646
 kill_block_super+0x44/0x90 fs/super.c:1725
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline]
 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888029052c00
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 8 bytes inside of
 freed 256-byte region [ffff888029052c00, ffff888029052d00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x29052
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 ffff88801a01db40 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 0080000000000040 ffff88801a01db40 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 0080000000000001 ffffffffffffff81 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 0xd2000(__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 175, tgid 175 (kworker/u8:7), ts 9976145796, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1860
 prep_new_page mm/page_alloc.c:1868 [inline]
 get_page_from_freelist+0x27c8/0x2840 mm/page_alloc.c:3948
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5228
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3467
 new_slab mm/slub.c:3525 [inline]
 refill_objects+0x33c/0x3d0 mm/slub.c:7251
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 __kmalloc_cache_node_noprof+0x4f2/0x6c0 mm/slub.c:5423
 kmalloc_node_noprof include/linux/slab.h:1077 [inline]
 blk_alloc_flush_queue+0x7f/0x240 block/blk-flush.c:485
 blk_mq_init_hctx block/blk-mq.c:4019 [inline]
 blk_mq_alloc_and_init_hctx+0x7bd/0xc70 block/blk-mq.c:4558
 __blk_mq_realloc_hw_ctxs+0x2bd/0x670 block/blk-mq.c:4605
 blk_mq_realloc_hw_ctxs block/blk-mq.c:4642 [inline]
 blk_mq_init_allocated_queue+0x36a/0x1420 block/blk-mq.c:4672
 blk_mq_alloc_queue+0x1ba/0x2e0 block/blk-mq.c:4454
 scsi_alloc_sdev+0x7c8/0xc90 drivers/scsi/scsi_scan.c:339
 scsi_probe_and_add_lun+0x200/0x4830 drivers/scsi/scsi_scan.c:1215
 __scsi_scan_target+0x1f0/0xe10 drivers/scsi/scsi_scan.c:1786
 scsi_scan_channel drivers/scsi/scsi_scan.c:1874 [inline]
 scsi_scan_host_selected+0x375/0x690 drivers/scsi/scsi_scan.c:1903
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888029052b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888029052b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888029052c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff888029052c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888029052d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (578):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/17 06:43 upstream 3cd8b194bf34 de0a551d .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/17 05:17 upstream 3cd8b194bf34 de0a551d .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/17 05:02 upstream 3cd8b194bf34 de0a551d .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/15 09:06 linux-next e6efabc0afca e2e976a8 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/15 06:59 linux-next e6efabc0afca e2e976a8 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/17 06:37 upstream 3cd8b194bf34 de0a551d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/17 06:29 upstream 3cd8b194bf34 de0a551d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/17 05:27 upstream 3cd8b194bf34 de0a551d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/17 04:10 upstream 3cd8b194bf34 de0a551d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/17 03:18 upstream 3cd8b194bf34 de0a551d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/17 02:40 upstream 3cd8b194bf34 de0a551d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/17 02:18 upstream 3cd8b194bf34 de0a551d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/17 01:52 upstream 3cd8b194bf34 de0a551d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/17 01:47 upstream 3cd8b194bf34 de0a551d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 22:51 upstream 1d51b370a0f8 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 22:17 upstream 1d51b370a0f8 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 21:17 upstream 1d51b370a0f8 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 21:01 upstream 1d51b370a0f8 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 19:58 upstream 1d51b370a0f8 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 18:52 upstream 1d51b370a0f8 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 18:04 upstream 1d51b370a0f8 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 17:02 upstream 1d51b370a0f8 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 16:52 upstream 1d51b370a0f8 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 15:33 upstream 1d51b370a0f8 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 15:10 upstream 1d51b370a0f8 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 14:30 upstream 1d51b370a0f8 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 13:54 upstream 1d51b370a0f8 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 13:40 upstream 1d51b370a0f8 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2025/12/16 17:21 upstream 40fbbd64bba6 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 19:16 linux-next 452c3b1ea875 321ae225 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 07:35 linux-next e6efabc0afca df15c5f3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 05:55 linux-next e6efabc0afca df15c5f3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 04:19 linux-next e6efabc0afca df15c5f3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 02:12 linux-next e6efabc0afca df15c5f3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/16 01:37 linux-next e6efabc0afca df15c5f3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/15 20:45 linux-next e6efabc0afca c441f497 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/15 17:23 linux-next e6efabc0afca c441f497 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/15 14:45 linux-next e6efabc0afca c441f497 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/15 12:31 linux-next e6efabc0afca c441f497 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/15 12:06 linux-next e6efabc0afca c441f497 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/15 08:07 linux-next e6efabc0afca e2e976a8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/15 05:18 linux-next e6efabc0afca e2e976a8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/15 02:41 linux-next e6efabc0afca e2e976a8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/15 00:59 linux-next e6efabc0afca e2e976a8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/15 00:14 linux-next e6efabc0afca e2e976a8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/14 23:09 linux-next e6efabc0afca 362d1323 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/14 20:58 linux-next e6efabc0afca 362d1323 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/14 19:54 linux-next e6efabc0afca 362d1323 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/04/14 18:46 linux-next e6efabc0afca 362d1323 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: slab-use-after-free Read in lbmIODone
2026/01/28 09:20 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 59e4d31a0470 3029c699 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: slab-use-after-free Read in lbmIODone
2025/09/24 23:55 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 0f3be52b8e37 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: slab-use-after-free Read in lbmIODone
* Struck through repros no longer work on HEAD.