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

Status: upstream: reported C repro on 2025/06/18 00:01
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+abbdf51b9e61595e687d@syzkaller.appspotmail.com
First crash: 309d, last: 14h58m
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2025/06/22 upstream (ToT) 739a6c93cc75 C [report] KASAN: slab-use-after-free Read in jfs_lazycommit
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in jfs_lazycommit jfs 19 C error 3983 16h08m 1299d 0/29 upstream: reported C repro on 2022/10/01 13:43
linux-4.19 KASAN: use-after-free Read in jfs_lazycommit jfs 19 C error 5 1170d 1287d 0/1 upstream: reported C repro on 2022/10/13 08:33
linux-6.1 KASAN: use-after-free Read in jfs_lazycommit origin:upstream missing-backport 19 C inconclusive 379 20h24m 1081d 0/3 upstream: reported C repro on 2023/05/07 23:35
linux-5.15 KASAN: use-after-free Read in jfs_lazycommit origin:upstream 19 C error 410 9d13h 1082d 0/3 upstream: reported C repro on 2023/05/06 12:04
linux-4.14 KASAN: use-after-free Read in jfs_lazycommit jfs 19 C 6 1147d 1289d 0/1 upstream: reported C repro on 2022/10/11 20:09

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x753/0xa60 fs/jfs/jfs_txnmgr.c:2735
Read of size 4 at addr ffff88802fea6494 by task jfsCommit/114

CPU: 1 PID: 114 Comm: jfsCommit Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xac/0x220 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 jfs_lazycommit+0x753/0xa60 fs/jfs/jfs_txnmgr.c:2735
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>

Allocated by task 6027:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 jfs_fill_super+0xd6/0xac0 fs/jfs/super.c:495
 mount_bdev+0x22b/0x2d0 fs/super.c:1643
 legacy_get_tree+0xea/0x180 fs/fs_context.c:662
 vfs_get_tree+0x8c/0x280 fs/super.c:1764
 do_new_mount+0x24b/0xa40 fs/namespace.c:3386
 do_mount fs/namespace.c:3726 [inline]
 __do_sys_mount fs/namespace.c:3935 [inline]
 __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3912
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 5910:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843
 generic_shutdown_super+0x134/0x2b0 fs/super.c:693
 kill_block_super+0x44/0x90 fs/super.c:1660
 deactivate_locked_super+0x97/0x100 fs/super.c:481
 cleanup_mnt+0x429/0x4c0 fs/namespace.c:1259
 task_work_run+0x1ce/0x250 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88802fea6400
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 148 bytes inside of
 freed 256-byte region [ffff88802fea6400, ffff88802fea6500)

The buggy address belongs to the physical page:
page:ffffea0000bfa980 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802fea7000 pfn:0x2fea6
head:ffffea0000bfa980 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017841b40 ffff888017840708 ffffea000181a190
raw: ffff88802fea7000 000000000010000b 00000001ffffffff 0000000000000000
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 20049347437, free_ts 0
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2120
 alloc_slab_page+0x5d/0x170 mm/slub.c:1881
 allocate_slab mm/slub.c:2028 [inline]
 new_slab+0x87/0x2e0 mm/slub.c:2081
 ___slab_alloc+0xc6d/0x1300 mm/slub.c:3253
 __slab_alloc mm/slub.c:3339 [inline]
 __slab_alloc_node mm/slub.c:3392 [inline]
 slab_alloc_node mm/slub.c:3485 [inline]
 __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3534
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027
 __do_krealloc mm/slab_common.c:1402 [inline]
 krealloc+0x86/0x120 mm/slab_common.c:1435
 add_sysfs_param+0xe8/0x950 kernel/params.c:652
 kernel_add_sysfs_param+0xaf/0x120 kernel/params.c:813
 param_sysfs_builtin+0x1e0/0x280 kernel/params.c:852
 param_sysfs_builtin_init+0x2d/0x30 kernel/params.c:988
 do_one_initcall+0x1fd/0x750 init/main.c:1250
 do_initcall_level+0x137/0x1f0 init/main.c:1312
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802fea6380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802fea6400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802fea6480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff88802fea6500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802fea6580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (127):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/08 03:21 linux-6.6.y 0a805b6ea8cd 4e1406b4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/09/28 19:29 linux-6.6.y 147338df3487 001c9061 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/06/20 07:33 linux-6.6.y 6282921b6825 ed3e87f7 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/22 12:45 linux-6.6.y 9760bf04666d 4595e353 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/21 19:48 linux-6.6.y 9760bf04666d 0b6ab7ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/18 09:41 linux-6.6.y 8cee53b8eaeb 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/16 13:21 linux-6.6.y 8cee53b8eaeb 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/15 06:06 linux-6.6.y 8cee53b8eaeb e2e976a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/15 03:00 linux-6.6.y 8cee53b8eaeb e2e976a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/12 18:16 linux-6.6.y 8cee53b8eaeb 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/12 08:44 linux-6.6.y 8cee53b8eaeb 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/11 11:48 linux-6.6.y 80de0a958133 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/06 13:01 linux-6.6.y 80de0a958133 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/06 09:10 linux-6.6.y 80de0a958133 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/03 01:47 linux-6.6.y c09fbcd31ae6 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/02 14:15 linux-6.6.y c09fbcd31ae6 91bc79b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/01 05:41 linux-6.6.y c09fbcd31ae6 fb8b2c26 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/27 23:58 linux-6.6.y c09fbcd31ae6 74a13a23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/27 18:22 linux-6.6.y c09fbcd31ae6 74a13a23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/27 08:40 linux-6.6.y c09fbcd31ae6 766b6434 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/23 06:29 linux-6.6.y 4fc00fe35d46 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/23 00:48 linux-6.6.y 4fc00fe35d46 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/23 00:42 linux-6.6.y 4fc00fe35d46 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/12 21:40 linux-6.6.y 4fc00fe35d46 4efadf07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/11 22:53 linux-6.6.y 4fc00fe35d46 2d88ab01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/11 20:09 linux-6.6.y 4fc00fe35d46 2d88ab01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/11 05:25 linux-6.6.y 4fc00fe35d46 86914af9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/10 16:50 linux-6.6.y 4fc00fe35d46 4683d576 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/08 22:05 linux-6.6.y 4fc00fe35d46 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/08 01:10 linux-6.6.y 4fc00fe35d46 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/07 09:15 linux-6.6.y 4fc00fe35d46 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/07 03:16 linux-6.6.y 4fc00fe35d46 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/06 02:23 linux-6.6.y 4fc00fe35d46 31e9c887 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/05 02:45 linux-6.6.y 682d8e2f892b a9fe5c9e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/03/04 20:46 linux-6.6.y 682d8e2f892b e6b6b96b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/02/26 14:10 linux-6.6.y 7a137e9bfa0e ffa54287 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/02/24 16:18 linux-6.6.y 7a137e9bfa0e 96b1aa46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/02/24 14:02 linux-6.6.y 7a137e9bfa0e 96b1aa46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/02/24 01:55 linux-6.6.y 7a137e9bfa0e 41d2fa6a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/02/22 05:26 linux-6.6.y 7a137e9bfa0e 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/02/21 12:43 linux-6.6.y 7a137e9bfa0e 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/02/20 20:11 linux-6.6.y 7a137e9bfa0e 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/02/20 09:31 linux-6.6.y 7a137e9bfa0e 17d780d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/02/19 06:34 linux-6.6.y 56865d9b7074 746545b8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/02/19 01:36 linux-6.6.y 56865d9b7074 77d4d919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/02/11 17:29 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/06/17 23:15 linux-6.6.y c2603c511feb e77fae15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2026/04/21 18:42 linux-6.6.y 9760bf04666d 0b6ab7ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in jfs_lazycommit
2026/04/20 16:50 linux-6.6.y 9760bf04666d e65da4ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in jfs_lazycommit
2026/04/08 01:36 linux-6.6.y 80de0a958133 2c961e87 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in jfs_lazycommit
2026/04/02 20:20 linux-6.6.y c09fbcd31ae6 91bc79b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in jfs_lazycommit
* Struck through repros no longer work on HEAD.