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UBSAN: array-index-out-of-bounds in dtSplitPage

Status: upstream: reported C repro on 2024/12/29 06:57
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+63c40a3ef45fce944739@syzkaller.appspotmail.com
First crash: 397d, last: 4d22h
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2025/10/17 upstream (ToT) 6f3b6e91f720 C [report] KASAN: slab-out-of-bounds Read in dtSplitPage
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 UBSAN: array-index-out-of-bounds in dtSplitPage origin:upstream 24 C 134 3d08h 223d 0/2 upstream: reported C repro on 2025/06/20 22:01
upstream KASAN: slab-use-after-free Write in dtSplitPage jfs 24 C inconclusive 6568 now 410d 0/29 upstream: reported C repro on 2024/12/15 23:15
linux-6.1 UBSAN: array-index-out-of-bounds in dtSplitPage origin:upstream 24 C 250 2d06h 396d 0/3 upstream: reported C repro on 2024/12/30 07:45
▶ ▼ Last patch testing requests (4)
Created Duration User Patch Repo Result
2025/10/27 08:49 10m retest repro linux-5.15.y report log
2025/10/11 10:33 39m retest repro linux-5.15.y report log
2025/10/08 15:37 16m retest repro linux-5.15.y OK log
2025/04/10 17:57 26m retest repro linux-5.15.y report log

Sample crash report:
loop0: detected capacity change from 0 to 32768
 ... Log Wrap ... Log Wrap ... Log Wrap ...
read_mapping_page failed!
ERROR: (device loop0): txCommit: 
read_mapping_page failed!
ERROR: (device loop0): txCommit: 
==================================================================
BUG: KASAN: slab-out-of-bounds in dtSplitPage+0x1066/0x3200 fs/jfs/jfs_dtree.c:-1
Read of size 1 at addr ffff88805cc4b775 by task syz.0.17/4321

CPU: 0 PID: 4321 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 dtSplitPage+0x1066/0x3200 fs/jfs/jfs_dtree.c:-1
 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
 dtInsert+0xff4/0x5830 fs/jfs/jfs_dtree.c:871
 jfs_create+0x730/0xad0 fs/jfs/namei.c:137
 lookup_open fs/namei.c:3470 [inline]
 open_last_lookups fs/namei.c:3540 [inline]
 path_openat+0x11db/0x2fa0 fs/namei.c:3747
 do_filp_open+0x1e2/0x410 fs/namei.c:3777
 do_sys_openat2+0x150/0x4b0 fs/open.c:1255
 do_sys_open fs/open.c:1271 [inline]
 __do_sys_openat fs/open.c:1287 [inline]
 __se_sys_openat fs/open.c:1282 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1282
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fced636acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc3c6d62e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fced65e5fa0 RCX: 00007fced636acb9
RDX: 0000000000183341 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007fced63d8bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000050 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fced65e5fac R14: 00007fced65e5fa0 R15: 00007fced65e5fa0
 </TASK>

Allocated by task 4321:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
 jfs_alloc_inode+0x17/0x50 fs/jfs/super.c:105
 alloc_inode fs/inode.c:261 [inline]
 iget_locked+0x191/0x820 fs/inode.c:1308
 jfs_iget+0x20/0x3f0 fs/jfs/inode.c:29
 jfs_lookup+0x21d/0x420 fs/jfs/namei.c:1467
 __lookup_slow+0x29d/0x410 fs/namei.c:1671
 lookup_slow+0x53/0x70 fs/namei.c:1688
 walk_component+0x319/0x460 fs/namei.c:1984
 lookup_last fs/namei.c:2439 [inline]
 path_lookupat+0x169/0x440 fs/namei.c:2463
 filename_lookup+0x214/0x540 fs/namei.c:2492
 user_path_at_empty+0x40/0x190 fs/namei.c:2891
 user_path_at include/linux/namei.h:57 [inline]
 __do_sys_chdir fs/open.c:490 [inline]
 __se_sys_chdir+0x98/0x280 fs/open.c:484
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff88805cc4ae40
 which belongs to the cache jfs_ip of size 2240
The buggy address is located 117 bytes to the right of
 2240-byte region [ffff88805cc4ae40, ffff88805cc4b700)
The buggy address belongs to the page:
page:ffffea0001731200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5cc48
head:ffffea0001731200 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff88807e654e01
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888146111dc0
raw: 0000000000000000 00000000800d000d 00000001ffffffff ffff88807e654e01
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0x1d2050(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 4321, ts 71441211355, free_ts 60812170520
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5487
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x195/0x290 mm/slub.c:3238
 jfs_alloc_inode+0x17/0x50 fs/jfs/super.c:105
 alloc_inode fs/inode.c:261 [inline]
 new_inode_pseudo+0x5f/0x210 fs/inode.c:1001
 new_inode+0x25/0x1c0 fs/inode.c:1030
 diReadSpecial+0x4e/0x700 fs/jfs/jfs_imap.c:426
 jfs_mount+0x6f/0x860 fs/jfs/jfs_mount.c:87
 jfs_fill_super+0x511/0xb00 fs/jfs/super.c:561
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
 __vunmap+0x8b9/0xa50 mm/vmalloc.c:2628
 kcov_put kernel/kcov.c:417 [inline]
 kcov_close+0x27/0x50 kernel/kcov.c:519
 __fput+0x234/0x930 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x626/0x20c0 kernel/exit.c:883
 do_group_exit+0x12e/0x300 kernel/exit.c:997
 get_signal+0x6ca/0x12c0 kernel/signal.c:2900
 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff88805cc4b600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805cc4b680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805cc4b700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                             ^
 ffff88805cc4b780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805cc4b800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (125):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/23 07:41 linux-5.15.y 9eec9a14ee10 82c9c083 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/10/12 21:35 linux-5.15.y 29e53a5b1c4f ff1712fe .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/06/24 11:37 linux-5.15.y 1c700860e8bc e2f27c35 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/04/18 01:47 linux-5.15.y f7347f400572 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: array-index-out-of-bounds in dtSplitPage
2025/03/16 10:26 linux-5.15.y 0c935c049b5c e2826670 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan UBSAN: array-index-out-of-bounds in dtSplitPage
2024/12/29 06:56 linux-5.15.y 91786f140358 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: array-index-out-of-bounds in dtSplitPage
2026/01/25 16:59 linux-5.15.y 9eec9a14ee10 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/23 03:35 linux-5.15.y 9eec9a14ee10 82c9c083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/15 14:46 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/15 08:42 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/15 06:02 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/13 03:57 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/09 21:18 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/09 13:04 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/07 03:26 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/06 23:21 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/02 06:38 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/01 12:07 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/30 23:33 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/28 08:26 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/21 05:04 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/15 05:04 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/11 02:34 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/11/28 02:11 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/11/26 21:35 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in dtSplitPage
2025/11/12 04:33 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/11/12 00:09 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/11/10 02:57 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/11/09 14:24 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/11/02 07:03 linux-5.15.y cc5ec8769306 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/10/12 21:07 linux-5.15.y 29e53a5b1c4f ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/09/23 10:07 linux-5.15.y 43bb85222e53 0ac7291c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/09/19 22:04 linux-5.15.y 43bb85222e53 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/09/19 22:04 linux-5.15.y 43bb85222e53 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/09/19 08:06 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/09/18 10:37 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/09/17 23:46 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/09/17 14:22 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/09/17 10:33 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/09/16 07:40 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/09/13 22:26 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/08/27 02:41 linux-5.15.y c79648372d02 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/08/26 05:39 linux-5.15.y c79648372d02 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/08/24 22:20 linux-5.15.y c79648372d02 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/08/12 09:23 linux-5.15.y c79648372d02 c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/08/10 14:01 linux-5.15.y c79648372d02 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/08/04 15:32 linux-5.15.y c79648372d02 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/07/29 01:51 linux-5.15.y c79648372d02 6654ea9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/06/11 22:52 linux-5.15.y 1c700860e8bc 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Write in dtSplitPage
2025/07/31 12:22 linux-5.15.y c79648372d02 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/07/28 07:29 linux-5.15.y c79648372d02 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/07/28 03:49 linux-5.15.y c79648372d02 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
* Struck through repros no longer work on HEAD.