syzbot


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

Status: upstream: reported C repro on 2024/04/28 12:32
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+77ed0aca57849509422b@syzkaller.appspotmail.com
First crash: 815d, last: 3d05h
Fix bisection: failed (error log, bisect log)
  
Bug presence (1)
Date Name Commit Repro Result
2025/04/30 upstream (ToT) 7a13c14ee59d C [report] KASAN: slab-out-of-bounds Read in dtReadFirst
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 UBSAN: array-index-out-of-bounds in dtReadFirst origin:lts-only 19 C error 25 142d 604d 0/3 upstream: reported C repro on 2024/11/25 10:09
upstream UBSAN: array-index-out-of-bounds in dtReadFirst jfs 19 C error 200 585d 812d 28/29 fixed on 2024/12/16 09:50
upstream UBSAN: array-index-out-of-bounds in dtReadFirst (2) jfs 19 C error 119 450d 578d 28/29 fixed on 2025/06/10 16:19
upstream KASAN: slab-out-of-bounds Read in dtReadFirst prio:high jfs 19 C error error 69 101d 378d 0/29 upstream: reported C repro on 2025/07/09 11:02
linux-6.6 KASAN: slab-out-of-bounds Read in dtReadFirst origin:upstream missing-backport 17 C error 2 46d 209d 0/2 upstream: reported C repro on 2025/12/25 14:42
Last patch testing requests (7)
Created Duration User Patch Repo Result
2026/05/27 21:07 17m retest repro linux-5.15.y report log
2026/03/14 20:12 51m retest repro linux-5.15.y error
2026/01/03 18:53 15m retest repro linux-5.15.y report log
2025/10/15 01:04 11m retest repro linux-5.15.y report log
2025/07/23 00:54 12m retest repro linux-5.15.y report log
2025/05/11 12:10 11m retest repro linux-5.15.y report log
2025/04/26 12:40 19m retest repro linux-5.15.y OK log

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in addressPXD fs/jfs/jfs_types.h:80 [inline]
BUG: KASAN: slab-out-of-bounds in dtReadFirst+0x4f7/0x900 fs/jfs/jfs_dtree.c:3418
Read of size 4 at addr ffff88805eacc050 by task syz-executor/4300

CPU: 1 PID: 4300 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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
 addressPXD fs/jfs/jfs_types.h:80 [inline]
 dtReadFirst+0x4f7/0x900 fs/jfs/jfs_dtree.c:3418
 jfs_readdir+0x88b/0x3d40 fs/jfs/jfs_dtree.c:3130
 iterate_dir+0x213/0x550 fs/readdir.c:-1
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64+0xf2/0x270 fs/readdir.c:354
 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: 0033:0x7ff85a390833
Code: c7 c0 e8 ff ff ff 64 c7 00 16 00 00 00 31 c0 eb 9e e8 81 9b fd ff 90 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 e8 ff ff ff f7 d8
RSP: 002b:00007ffe387dad08 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 0000555595489a40 RCX: 00007ff85a390833
RDX: 0000000000008000 RSI: 0000555595489a70 RDI: 0000000000000005
RBP: 0000555595489a70 R08: 00000000000285d1 R09: 0000000000000001
R10: 00007ff85a5bae20 R11: 0000000000000293 R12: 0000555595489a44
R13: ffffffffffffffe8 R14: 0000000000000010 R15: 00007ffe387dcfb0
 </TASK>

Allocated by task 4315:
 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+0x92/0xc0 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+0x15d/0x280 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+0x25/0x1d0 fs/inode.c:1030
 ialloc+0x49/0x920 fs/jfs/jfs_inode.c:48
 jfs_create+0x1d5/0xae0 fs/jfs/namei.c:92
 lookup_open fs/namei.c:3470 [inline]
 open_last_lookups fs/namei.c:3540 [inline]
 path_openat+0x120a/0x2fb0 fs/namei.c:3747
 do_filp_open+0x1df/0x400 fs/namei.c:3777
 do_sys_openat2+0x14b/0x500 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

The buggy address belongs to the object at ffff88805eacb780
 which belongs to the cache jfs_ip of size 2240
The buggy address is located 16 bytes to the right of
 2240-byte region [ffff88805eacb780, ffff88805eacc040)
The buggy address belongs to the page:
page:ffffea00017ab200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5eac8
head:ffffea00017ab200 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff88807c17c901
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff88801ded7000
raw: 0000000000000000 00000000800d000d 00000001ffffffff ffff88807c17c901
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 4315, ts 80815210630, free_ts 70199720125
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 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+0x807/0xdd0 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+0xf0/0x280 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+0x25/0x1d0 fs/inode.c:1030
 jfs_fill_super+0x37b/0xad0 fs/jfs/super.c:549
 mount_bdev+0x28a/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+0x247/0xa40 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
 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
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_list+0x119/0x830 mm/page_alloc.c:3433
 release_pages+0x185f/0x1bd0 mm/swap.c:963
 tlb_batch_pages_flush mm/mmu_gather.c:50 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:241 [inline]
 tlb_flush_mmu mm/mmu_gather.c:248 [inline]
 tlb_finish_mmu+0x1b4/0x370 mm/mmu_gather.c:371
 unmap_region+0x344/0x3b0 mm/mmap.c:2669
 __do_munmap+0xa29/0xe10 mm/mmap.c:2899
 __vm_munmap+0x13f/0x240 mm/mmap.c:2952
 __do_sys_munmap mm/mmap.c:2978 [inline]
 __se_sys_munmap mm/mmap.c:2974 [inline]
 __x64_sys_munmap+0x67/0x70 mm/mmap.c:2974
 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

Memory state around the buggy address:
 ffff88805eacbf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805eacbf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805eacc000: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                                 ^
 ffff88805eacc080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88805eacc100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (36):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/19 22:35 linux-5.15.y c86c4726e7f0 72524a66 .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 dtReadFirst
2025/04/27 10:45 linux-5.15.y f7347f400572 c6b4fb39 .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 dtReadFirst
2025/04/09 06:17 linux-5.15.y 0c935c049b5c a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: array-index-out-of-bounds in dtReadFirst
2025/04/09 06:17 linux-5.15.y 0c935c049b5c a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: array-index-out-of-bounds in dtReadFirst
2025/02/23 11:51 linux-5.15.y c16c81c81336 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: array-index-out-of-bounds in dtReadFirst
2025/02/16 19:01 linux-5.15.y c16c81c81336 40a34ec9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: array-index-out-of-bounds in dtReadFirst
2025/02/16 19:01 linux-5.15.y c16c81c81336 40a34ec9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: array-index-out-of-bounds in dtReadFirst
2025/01/20 03:34 linux-5.15.y 4735586da88e f2cb035c .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan UBSAN: array-index-out-of-bounds in dtReadFirst
2025/01/20 03:09 linux-5.15.y 4735586da88e f2cb035c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: array-index-out-of-bounds in dtReadFirst
2024/12/01 23:23 linux-5.15.y 0a51d2d4527b 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: array-index-out-of-bounds in dtReadFirst
2024/12/01 23:21 linux-5.15.y 0a51d2d4527b 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: array-index-out-of-bounds in dtReadFirst
2024/11/26 05:26 linux-5.15.y 0a51d2d4527b 11dbc254 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan UBSAN: array-index-out-of-bounds in dtReadFirst
2025/04/09 03:39 linux-5.15.y 0c935c049b5c a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2025/04/09 03:39 linux-5.15.y 0c935c049b5c a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2025/03/30 10:06 linux-5.15.y 0c935c049b5c d3999433 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2025/03/02 11:23 linux-5.15.y c16c81c81336 c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2025/02/28 07:19 linux-5.15.y c16c81c81336 6a8fcbc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2025/02/17 00:31 linux-5.15.y c16c81c81336 40a34ec9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2024/12/01 23:13 linux-5.15.y 0a51d2d4527b 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2024/12/01 23:11 linux-5.15.y 0a51d2d4527b 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2024/11/26 03:48 linux-5.15.y 0a51d2d4527b 11dbc254 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2024/11/26 03:48 linux-5.15.y 0a51d2d4527b 11dbc254 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2024/10/05 21:53 linux-5.15.y 3a5928702e71 d7906eff .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2024/10/05 21:22 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2024/05/27 23:22 linux-5.15.y c61bd26ae81a 761766e6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2024/05/27 22:08 linux-5.15.y c61bd26ae81a 761766e6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2024/05/12 13:01 linux-5.15.y 284087d4f7d5 9026e142 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2024/04/28 13:09 linux-5.15.y b925f60c6ee7 07b455f9 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2024/04/28 12:31 linux-5.15.y b925f60c6ee7 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 UBSAN: array-index-out-of-bounds in dtReadFirst
2026/07/19 21:36 linux-5.15.y c86c4726e7f0 72524a66 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtReadFirst
2025/12/19 15:53 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 dtReadFirst
2025/10/01 00:21 linux-5.15.y 43bb85222e53 65a0eece .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtReadFirst
2025/02/05 10:19 linux-5.15.y c16c81c81336 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtReadFirst
2025/02/05 03:49 linux-5.15.y c16c81c81336 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in dtReadFirst
2025/04/27 10:14 linux-5.15.y f7347f400572 c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: slab-out-of-bounds Read in dtReadFirst
2025/02/16 23:52 linux-5.15.y c16c81c81336 40a34ec9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: slab-out-of-bounds Read in dtReadFirst
* Struck through repros no longer work on HEAD.