UBSAN: shift-out-of-bounds in dbSplit (3)

Status: fixed on 2026/05/21 07:50
Subsystems: jfs
[Documentation on labels]
Reported-by: syzbot+4c1966e88c28fa96e053@syzkaller.appspotmail.com
Fix commit: cce219b203c4 jfs: add dmapctl integrity check to prevent invalid operations
First crash: 552d, last: 234d
▶ ▼ Discussions (4)
Title Replies (including bot) Last reply
[PATCH AUTOSEL 7.0-5.10] jfs: add dmapctl integrity check to prevent invalid operations 1 (1) 2026/04/20 13:08
[PATCH v2] jfs: add dmapctl integrity check to prevent invalid operations 5 (5) 2026/03/16 21:12
[PATCH] jfs: add dmapctl integrity check to prevent invalid operations 2 (2) 2025/11/24 11:42
[syzbot] [jfs?] UBSAN: shift-out-of-bounds in dbSplit (3) 0 (3) 2025/11/19 02:55
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 UBSAN: shift-out-of-bounds in dbSplit (2) origin:upstream -1 syz, C error 1 533d 600d 0/3 upstream: reported C repro on 2025/03/09 22:23
linux-6.1 UBSAN: shift-out-of-bounds in dbSplit -1 syz, C done 18 711d 928d 3/3 fixed on 2025/01/09 09:39
upstream UBSAN: shift-out-of-bounds in dbSplit (2) jfs -1 syz, C error 403 697d 942d 28/29 fixed on 2024/12/16 09:50
upstream UBSAN: shift-out-of-bounds in dbSplit jfs -1 syz, C error done 7 1034d 1488d 25/29 fixed on 2024/02/09 18:10
linux-5.15 UBSAN: shift-out-of-bounds in dbSplit origin:upstream -1 syz, C error 36 46d 928d 0/3 upstream: reported C repro on 2024/04/15 22:09
▶ ▼ Last patch testing requests (12)
Created Duration User Patch Repo Result
2026/03/06 05:20 17m retest repro upstream report log
2026/02/15 22:11 14m retest repro upstream log
2025/12/26 04:59 14m retest repro upstream report log
2025/12/26 04:59 14m retest repro upstream report log
2025/12/07 21:10 14m retest repro upstream report log
2025/11/19 02:55 20m yun.zhou@windriver.com patch upstream report log
2025/10/12 20:15 14m retest repro upstream report log
2025/10/12 20:15 14m retest repro upstream report log
2025/09/28 19:59 13m xandfury@gmail.com upstream report log
2025/07/26 03:00 11m retest repro upstream report log
2025/07/26 03:00 29m retest repro upstream report log
2025/07/26 03:00 14m retest repro upstream report log

Sample crash report:
loop0: detected capacity change from 0 to 32768
------------[ cut here ]------------
UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:2629:11
shift exponent 110 is too large for 32-bit type 'int'
CPU: 0 UID: 0 PID: 5303 Comm: syz-executor956 Not tainted 6.15.0-rc3-syzkaller-00283-gf1a3944c860b #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 ubsan_epilogue+0xa/0x40 lib/ubsan.c:231
 __ubsan_handle_shift_out_of_bounds+0x386/0x410 lib/ubsan.c:492
 dbSplit+0x1f8/0x200 fs/jfs/jfs_dmap.c:2629
 dbAdjCtl+0x34c/0xa20 fs/jfs/jfs_dmap.c:2521
 dbAllocDmap fs/jfs/jfs_dmap.c:2032 [inline]
 dbAllocNear+0x2ee/0x3d0 fs/jfs/jfs_dmap.c:1243
 dbAlloc+0x933/0xba0 fs/jfs/jfs_dmap.c:828
 ea_write+0x374/0xdd0 fs/jfs/xattr.c:232
 ea_put fs/jfs/xattr.c:619 [inline]
 __jfs_setxattr+0xa01/0x1120 fs/jfs/xattr.c:792
 __jfs_xattr_set+0xda/0x170 fs/jfs/xattr.c:941
 __vfs_setxattr+0x439/0x480 fs/xattr.c:200
 __vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:234
 vfs_setxattr+0x16b/0x2f0 fs/xattr.c:321
 do_setxattr fs/xattr.c:636 [inline]
 filename_setxattr+0x274/0x600 fs/xattr.c:665
 path_setxattrat+0x364/0x3a0 fs/xattr.c:713
 __do_sys_lsetxattr fs/xattr.c:754 [inline]
 __se_sys_lsetxattr fs/xattr.c:750 [inline]
 __x64_sys_lsetxattr+0xbf/0xe0 fs/xattr.c:750
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdaa19996b9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffe3d43d28 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 0000200000000200 RCX: 00007fdaa19996b9
RDX: 0000000000000000 RSI: 0000200000000200 RDI: 0000200000000040
RBP: 00002000000000c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000040
R13: 0031656c69662f2e R14: 0000000000000001 R15: 0000000000000001
 </TASK>
---[ end trace ]---

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/26 23:10 upstream f1a3944c860b c6b4fb39 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-snapshot-upstream-root UBSAN: shift-out-of-bounds in dbSplit
2025/04/26 22:30 upstream f1a3944c860b c6b4fb39 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-snapshot-upstream-root UBSAN: shift-out-of-bounds in dbSplit
2025/04/26 21:50 upstream f1a3944c860b c6b4fb39 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-snapshot-upstream-root UBSAN: shift-out-of-bounds in dbSplit
2026/03/11 07:16 upstream b4f0dd314b39 86914af9 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root UBSAN: shift-out-of-bounds in dbSplit
2025/12/12 04:38 upstream d358e5254674 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root UBSAN: shift-out-of-bounds in dbSplit
2025/11/06 09:15 upstream dc77806cf3b4 a6c9c731 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root UBSAN: shift-out-of-bounds in dbSplit
2025/09/07 10:28 upstream b236920731dd d291dd2d .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root UBSAN: shift-out-of-bounds in dbSplit
2025/04/26 21:06 upstream f1a3944c860b c6b4fb39 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root UBSAN: shift-out-of-bounds in dbSplit
* Struck through repros no longer work on HEAD.