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

Status: upstream: reported C repro on 2024/12/30 07:45
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+a0acccd8e6068831fd3b@syzkaller.appspotmail.com
First crash: 378d, last: 1d13h
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2025/05/19 upstream (ToT) a5806cd506af C [report] KASAN: use-after-free Write 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 130 2d17h 205d 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 6114 8m 392d 0/29 upstream: reported C repro on 2024/12/15 23:15
linux-5.15 UBSAN: array-index-out-of-bounds in dtSplitPage origin:upstream 24 C 116 2d10h 379d 0/3 upstream: reported C repro on 2024/12/29 06:57

Sample crash report:
read_mapping_page failed!
ERROR: (device loop0): txCommit: 
read_mapping_page failed!
ERROR: (device loop0): txCommit: 
==================================================================
BUG: KASAN: slab-out-of-bounds in dtSplitPage+0x10d4/0x31d0 fs/jfs/jfs_dtree.c:-1
Read of size 1 at addr ffff888068f78935 by task syz.0.17/4419

CPU: 1 PID: 4419 Comm: syz.0.17 Not tainted 6.1.148-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:420
 kasan_report+0x10b/0x140 mm/kasan/report.c:524
 dtSplitPage+0x10d4/0x31d0 fs/jfs/jfs_dtree.c:-1
 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
 dtInsert+0xfbd/0x58a0 fs/jfs/jfs_dtree.c:871
 jfs_symlink+0x70f/0xe60 fs/jfs/namei.c:1019
 vfs_symlink+0x247/0x3d0 fs/namei.c:4471
 do_symlinkat+0x1ae/0x3f0 fs/namei.c:4500
 __do_sys_symlink fs/namei.c:4522 [inline]
 __se_sys_symlink fs/namei.c:4520 [inline]
 __x64_sys_symlink+0x7a/0x90 fs/namei.c:4520
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f58c298ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffeb9bbb4c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007f58c2bb5fa0 RCX: 00007f58c298ebe9
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000200000000080
RBP: 00007f58c2a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f58c2bb5fa0 R14: 00007f58c2bb5fa0 R15: 0000000000000002
 </TASK>

Allocated by task 4419:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737
 slab_alloc_node mm/slub.c:3398 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc_lru+0x11a/0x2e0 mm/slub.c:3429
 alloc_inode_sb include/linux/fs.h:3245 [inline]
 jfs_alloc_inode+0x24/0x60 fs/jfs/super.c:105
 alloc_inode fs/inode.c:261 [inline]
 iget_locked+0x1a9/0x830 fs/inode.c:1373
 jfs_iget+0x20/0x3c0 fs/jfs/inode.c:29
 jfs_lookup+0x1c2/0x380 fs/jfs/namei.c:1467
 __lookup_slow+0x27d/0x3a0 fs/namei.c:1690
 lookup_slow+0x53/0x70 fs/namei.c:1707
 walk_component+0x2be/0x3f0 fs/namei.c:1998
 lookup_last fs/namei.c:2455 [inline]
 path_lookupat+0x169/0x440 fs/namei.c:2479
 filename_lookup+0x1f0/0x500 fs/namei.c:2508
 user_path_at_empty+0x3e/0x60 fs/namei.c:2905
 user_path_at include/linux/namei.h:57 [inline]
 __do_sys_chdir fs/open.c:514 [inline]
 __se_sys_chdir+0x91/0x280 fs/open.c:508
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff888068f78000
 which belongs to the cache jfs_ip of size 2240
The buggy address is located 117 bytes to the right of
 2240-byte region [ffff888068f78000, ffff888068f788c0)

The buggy address belongs to the physical page:
page:ffffea0001a3de00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x68f78
head:ffffea0001a3de00 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff88807db8af01
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888019b94a00
raw: 0000000000000000 00000000800d000d 00000001ffffffff ffff88807db8af01
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 4419, tgid 4419 (syz.0.17), ts 77540655498, free_ts 14346604557
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532
 prep_new_page mm/page_alloc.c:2539 [inline]
 get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328
 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614
 alloc_slab_page+0x5d/0x160 mm/slub.c:1794
 allocate_slab mm/slub.c:1939 [inline]
 new_slab+0x87/0x2c0 mm/slub.c:1992
 ___slab_alloc+0xbc6/0x1220 mm/slub.c:3180
 __slab_alloc mm/slub.c:3279 [inline]
 slab_alloc_node mm/slub.c:3364 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc_lru+0x1ae/0x2e0 mm/slub.c:3429
 alloc_inode_sb include/linux/fs.h:3245 [inline]
 jfs_alloc_inode+0x24/0x60 fs/jfs/super.c:105
 alloc_inode fs/inode.c:261 [inline]
 iget_locked+0x1a9/0x830 fs/inode.c:1373
 jfs_iget+0x20/0x3c0 fs/jfs/inode.c:29
 jfs_lookup+0x1c2/0x380 fs/jfs/namei.c:1467
 __lookup_slow+0x27d/0x3a0 fs/namei.c:1690
 lookup_slow+0x53/0x70 fs/namei.c:1707
 walk_component+0x2be/0x3f0 fs/namei.c:1998
 lookup_last fs/namei.c:2455 [inline]
 path_lookupat+0x169/0x440 fs/namei.c:2479
 filename_lookup+0x1f0/0x500 fs/namei.c:2508
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1459 [inline]
 free_pcp_prepare mm/page_alloc.c:1509 [inline]
 free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384
 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479
 free_contig_range+0x9d/0x150 mm/page_alloc.c:9574
 destroy_args+0xef/0x8bf mm/debug_vm_pgtable.c:1031
 debug_vm_pgtable+0x32a/0x37e mm/debug_vm_pgtable.c:1354
 do_one_initcall+0x214/0x7a0 init/main.c:1298
 do_initcall_level+0x137/0x1e4 init/main.c:1371
 do_initcalls+0x4b/0x8a init/main.c:1387
 kernel_init_freeable+0x3fa/0x5ac init/main.c:1626
 kernel_init+0x19/0x1b0 init/main.c:1514
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Memory state around the buggy address:
 ffff888068f78800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888068f78880: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff888068f78900: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
                                     ^
 ffff888068f78980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888068f78a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (234):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/23 05:37 linux-6.1.y 0bc96de781b4 bf27483f .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/05/12 10:04 linux-6.1.y 02b72ccb5f9d 77908e5f .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan KASAN: use-after-free Write in dtSplitPage
2025/12/01 20:51 linux-6.1.y f6e38ae624cf d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/04/21 19:27 linux-6.1.y 420102835862 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan UBSAN: array-index-out-of-bounds in dtSplitPage
2024/12/30 07:45 linux-6.1.y 563edd786f0a d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan UBSAN: array-index-out-of-bounds in dtSplitPage
2026/01/09 12:32 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/07 00:24 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/02 02:54 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/30 23:37 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/30 23:28 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/27 17:34 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/23 03:37 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Read in dtSplitPage
2025/09/05 02:09 linux-6.1.y 28c695c365e1 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Write in dtSplitPage
2025/07/08 10:52 linux-6.1.y 04d1ccaa9c28 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Write in dtSplitPage
2026/01/10 18:28 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/10 17:03 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/09 10:22 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/08 13:05 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/07 21:33 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/07 03:37 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/07 03:24 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/06 22:23 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/06 19:23 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/06 12:02 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/05 07:23 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/04 19:17 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/04 09:40 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/04 03:22 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/03 23:04 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2026/01/03 00:25 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/28 07:25 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/27 19:20 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/27 08:43 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/27 00:10 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/26 18:11 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/25 18:51 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/25 12:56 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/25 11:25 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/25 08:47 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/25 01:19 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/24 16:52 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/24 14:12 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/23 14:12 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/23 12:05 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/22 22:37 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/22 17:15 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/21 06:03 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/20 23:34 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/20 20:22 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/20 09:42 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/18 20:13 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/12/17 19:58 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: slab-out-of-bounds Read in dtSplitPage
2025/11/01 07:54 linux-6.1.y f6e38ae624cf 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: use-after-free Read in dtSplitPage
* Struck through repros no longer work on HEAD.