KASAN: slab-out-of-bounds Read in xlog_cksum

Status: fixed on 2026/05/06 16:40
Subsystems: xfs
[Documentation on labels]
Reported-by: syzbot+9f6d080dece587cfdd4c@syzkaller.appspotmail.com
Fix commit: 44b9553c3dd0 xfs: validate log record version against superblock log version
First crash: 565d, last: 210d
Cause bisection: failed (error log, bisect log)
  
▶ ▼ Discussions (8)
Title Replies (including bot) Last reply
[PATCH v6] xfs: validate log record version against superblock log version 3 (3) 2026/01/30 09:52
[syzbot] Monthly xfs report (Dec 2025) 0 (1) 2025/12/30 09:53
[PATCH] xfs: ensure log recovery buffer is resized to avoid OOB 16 (16) 2025/11/25 17:06
[syzbot] [xfs?] KASAN: slab-out-of-bounds Read in xlog_cksum 5 (16) 2025/11/24 00:39
[syzbot] Monthly xfs report (Oct 2025) 0 (1) 2025/10/29 09:50
[syzbot] Monthly xfs report (Sep 2025) 0 (1) 2025/09/27 20:43
[syzbot] Monthly crypto report (Sep 2025) 0 (1) 2025/09/12 12:50
[syzbot] Monthly crypto report (Jul 2025) 0 (1) 2025/07/31 12:52
▶ ▼ Last patch testing requests (19)
Created Duration User Patch Repo Result
2026/01/14 18:06 14m retest repro upstream report log
2025/12/26 03:02 14m retest repro upstream report log
2025/12/26 03:02 15m retest repro upstream report log
2025/12/26 03:02 15m retest repro upstream report log
2025/12/26 03:02 14m retest repro upstream report log
2025/11/24 00:39 25m rpthibeault@gmail.com patch upstream OK log
2025/11/19 01:45 22m rpthibeault@gmail.com patch upstream OK log
2025/11/13 03:49 23m rpthibeault@gmail.com patch upstream OK log
2025/11/12 17:27 22m rpthibeault@gmail.com patch upstream OK log
2025/11/12 16:38 27m rpthibeault@gmail.com patch upstream OK log
2025/11/12 01:09 24m rpthibeault@gmail.com patch upstream OK log
2025/11/06 04:40 14m retest repro upstream report log
2025/10/21 20:25 14m retest repro upstream report log
2025/10/07 19:08 14m retest repro upstream report log
2025/10/07 19:08 14m retest repro upstream report log
2025/10/07 19:08 14m retest repro upstream report log
2025/03/13 04:12 15m sunjunchao2870@gmail.com upstream report log
2025/03/05 12:08 18m eadavis@qq.com patch upstream report log
2025/03/05 01:53 19m eadavis@qq.com patch upstream report log
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2025/12/07 09:00 2h04m bisect fix upstream OK (0) job log log

Sample crash report:
         and is ignored by this kernel. Remove the mand
         option from the mount to silence this warning.
=======================================================
XFS (loop0): Mounting V5 Filesystem bfdc47fc-10d8-4eed-a562-11a831b3f791
=========[  128.969313][ T6105] ==================================================================
BUG: KASAN: slab-out-of-bounds in crc32c_arch lib/crc/x86/crc32.h:90 [inline]
BUG: KASAN: slab-out-of-bounds in crc32c+0xd0/0x460 lib/crc/crc32-main.c:86
Read of size 8 at addr ffff888031d9e200 by task syz.0.17/6105

CPU: 1 UID: 0 PID: 6105 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 crc32c_arch lib/crc/x86/crc32.h:90 [inline]
 crc32c+0xd0/0x460 lib/crc/crc32-main.c:86
 xlog_cksum+0x92/0xf0 fs/xfs/xfs_log.c:1589
 xlog_recover_process+0x7a/0x1f0 fs/xfs/xfs_log_recover.c:2900
 xlog_do_recovery_pass+0x9cd/0xc30 fs/xfs/xfs_log_recover.c:3235
 xlog_verify_head+0x136/0x440 fs/xfs/xfs_log_recover.c:1058
 xlog_find_tail+0x5b4/0x830 fs/xfs/xfs_log_recover.c:1315
 xlog_recover+0x4b/0x3e0 fs/xfs/xfs_log_recover.c:3419
 xfs_log_mount+0x253/0x3e0 fs/xfs/xfs_log.c:667
 xfs_mountfs+0xe5e/0x2330 fs/xfs/xfs_mount.c:1031
 xfs_fs_fill_super+0x1185/0x15d0 fs/xfs/xfs_super.c:1965
 get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1692
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4324
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f57963d034a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007ffcf0f9a1a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffcf0f9a230 RCX: 00007f57963d034a
RDX: 0000200000000500 RSI: 0000200000000200 RDI: 00007ffcf0f9a1f0
RBP: 0000200000000500 R08: 00007ffcf0f9a230 R09: 0000000002218a5d
R10: 0000000002218a5d R11: 0000000000000246 R12: 0000200000000200
R13: 00007ffcf0f9a1f0 R14: 00000000000096bf R15: 0000200000000380
 </TASK>

Allocated by task 6105:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4376 [inline]
 __kvmalloc_node_noprof+0x28d/0x550 mm/slub.c:5067
 xlog_do_recovery_pass+0x106/0xc30 fs/xfs/xfs_log_recover.c:3016
 xlog_verify_head+0x136/0x440 fs/xfs/xfs_log_recover.c:1058
 xlog_find_tail+0x5b4/0x830 fs/xfs/xfs_log_recover.c:1315
 xlog_recover+0x4b/0x3e0 fs/xfs/xfs_log_recover.c:3419
 xfs_log_mount+0x253/0x3e0 fs/xfs/xfs_log.c:667
 xfs_mountfs+0xe5e/0x2330 fs/xfs/xfs_mount.c:1031
 xfs_fs_fill_super+0x1185/0x15d0 fs/xfs/xfs_super.c:1965
 get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1692
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4324
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888031d9e000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes to the right of
 allocated 512-byte region [ffff888031d9e000, ffff888031d9e200)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x31d9c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff888019841c80 ffffea0000c35e00 dead000000000002
raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 0080000000000040 ffff888019841c80 ffffea0000c35e00 dead000000000002
head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 0080000000000002 ffffea0000c76701 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5219, tgid 5219 (udevadm), ts 36841202363, free_ts 36747491034
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x2119/0x21b0 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148
 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:2492 [inline]
 allocate_slab+0x8a/0x370 mm/slub.c:2660
 new_slab mm/slub.c:2714 [inline]
 ___slab_alloc+0x8d1/0xdc0 mm/slub.c:3901
 __slab_alloc mm/slub.c:3992 [inline]
 __slab_alloc_node mm/slub.c:4067 [inline]
 slab_alloc_node mm/slub.c:4228 [inline]
 __kmalloc_cache_noprof+0xe6/0x320 mm/slub.c:4402
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 kernfs_fop_open+0x3f0/0xdd0 fs/kernfs/file.c:623
 do_dentry_open+0x9b1/0x1350 fs/open.c:965
 vfs_open+0x3b/0x350 fs/open.c:1095
 do_open fs/namei.c:3887 [inline]
 path_openat+0x2ef1/0x3840 fs/namei.c:4046
 do_filp_open+0x1fa/0x410 fs/namei.c:4073
 do_sys_openat2+0x121/0x1c0 fs/open.c:1435
 do_sys_open fs/open.c:1450 [inline]
 __do_sys_openat fs/open.c:1466 [inline]
 __se_sys_openat fs/open.c:1461 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1461
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5218 tgid 5218 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xb59/0xce0 mm/page_alloc.c:2895
 discard_slab mm/slub.c:2758 [inline]
 __put_partials+0x159/0x1a0 mm/slub.c:3223
 __slab_free+0x2b3/0x390 mm/slub.c:4565
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4191 [inline]
 slab_alloc_node mm/slub.c:4240 [inline]
 kmem_cache_alloc_lru_noprof+0x14c/0x310 mm/slub.c:4259
 alloc_inode+0xb8/0x1b0 fs/inode.c:348
 iget_locked+0xf0/0x570 fs/inode.c:1438
 kernfs_get_inode+0x4f/0x780 fs/kernfs/inode.c:253
 kernfs_iop_lookup+0x1f6/0x320 fs/kernfs/dir.c:1236
 lookup_open fs/namei.c:3686 [inline]
 open_last_lookups fs/namei.c:3807 [inline]
 path_openat+0x110a/0x3840 fs/namei.c:4043
 do_filp_open+0x1fa/0x410 fs/namei.c:4073
 do_sys_openat2+0x121/0x1c0 fs/open.c:1435
 do_sys_open fs/open.c:1450 [inline]
 __do_sys_openat fs/open.c:1466 [inline]
 __se_sys_openat fs/open.c:1461 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1461
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94

Memory state around the buggy address:
 ffff888031d9e100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888031d9e180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888031d9e200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff888031d9e280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888031d9e300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (15):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/12 14:31 upstream 320475fbd590 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs KASAN: slab-out-of-bounds Read in xlog_cksum
2025/12/12 02:47 upstream d358e5254674 d1b870e1 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in xlog_cksum
2025/09/23 19:06 upstream cec1e6e5d1ab e667a34f .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in xlog_cksum
2025/09/23 18:36 upstream cec1e6e5d1ab e667a34f .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in xlog_cksum
2025/09/12 12:23 upstream 320475fbd590 e2beed91 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in xlog_cksum
2025/03/04 16:14 upstream 99fa936e8e4f c3901742 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in xlog_cksum
2025/12/31 17:14 upstream c8ebd433459b d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in xlog_cksum
2025/09/15 07:44 upstream 79e8447ec662 e2beed91 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in xlog_cksum
2025/09/15 07:12 upstream 79e8447ec662 e2beed91 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in xlog_cksum
2025/09/12 13:45 upstream 320475fbd590 e2beed91 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in xlog_cksum
2025/09/12 12:36 upstream 320475fbd590 e2beed91 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in xlog_cksum
2025/09/12 12:11 upstream 320475fbd590 e2beed91 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in xlog_cksum
2025/03/04 15:54 upstream 99fa936e8e4f c3901742 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in xlog_cksum
2025/01/24 09:14 upstream e0b1f5914274 521b0ce3 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in xlog_cksum
2025/01/24 08:59 upstream e0b1f5914274 521b0ce3 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-out-of-bounds Read in xlog_cksum
* Struck through repros no longer work on HEAD.