syzbot


kernel BUG in dbFindLeaf

Status: upstream: reported C repro on 2025/12/19 23:48
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+b215f932b51a9ee989eb@syzkaller.appspotmail.com
First crash: 45d, last: 23d
Bug presence (1)
Date Name Commit Repro Result
2025/12/20 upstream (ToT) dd9b004b7ff3 C [report] kernel BUG in dbFindLeaf
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel BUG in dbFindLeaf jfs -1 C inconclusive 6384 1h59m 1225d 0/29 upstream: reported C repro on 2022/09/26 11:46
linux-4.19 kernel BUG in dbFindLeaf -1 1 1548d 1548d 0/1 auto-closed as invalid on 2022/03/07 18:32
linux-4.14 kernel BUG in dbFindLeaf -1 C 3 1077d 1219d 0/1 upstream: reported C repro on 2022/10/02 18:35
linux-6.1 kernel BUG in dbFindLeaf origin:upstream -1 C error 40 23d 913d 0/3 upstream: reported C repro on 2023/08/05 07:19
linux-5.15 kernel BUG in dbFindLeaf origin:upstream -1 C error 25 1d13h 940d 0/3 upstream: reported C repro on 2023/07/08 22:09
linux-4.19 kernel BUG in dbFindLeaf (2) -1 C error 6 1181d 1220d 0/1 upstream: reported C repro on 2022/10/02 04:21

Sample crash report:
syz.0.17[5926]: memfd_create() called without MFD_EXEC or MFD_NOEXEC_SEAL set
loop0: detected capacity change from 0 to 32768
BUG at fs/jfs/jfs_dmap.c:2983 assert(n < 4)
------------[ cut here ]------------
kernel BUG at fs/jfs/jfs_dmap.c:2983!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 5926 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:dbFindLeaf+0x517/0x520 fs/jfs/jfs_dmap.c:2983
Code: fe e9 51 ff ff ff e8 68 ea 87 fe 48 c7 c7 a0 cd e3 8a 48 c7 c6 e0 ca e3 8a ba a7 0b 00 00 48 c7 c1 80 d8 e3 8a e8 e9 84 5e 07 <0f> 0b 0f 1f 80 00 00 00 00 55 41 57 41 56 41 55 41 54 53 48 83 ec
RSP: 0018:ffffc900043afac0 EFLAGS: 00010246
RAX: 000000000000002b RBX: 00000000ffffffff RCX: d3219f4b2e11bc00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffc900043af7c7 R09: 1ffff92000875ef8
R10: dffffc0000000000 R11: fffff52000875ef9 R12: 0000000000000008
R13: 0000000000000060 R14: 000000000000005d R15: 0000000000000155
FS:  000055555edfd500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34463fff CR3: 000000002f5fe000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 dbAllocDmapLev+0x61/0x3c0 fs/jfs/jfs_dmap.c:1969
 dbAllocCtl+0x148/0x9b0 fs/jfs/jfs_dmap.c:1825
 dbAllocAG+0x1e7/0xfe0 fs/jfs/jfs_dmap.c:1353
 dbDiscardAG+0x2ce/0x8f0 fs/jfs/jfs_dmap.c:1608
 jfs_ioc_trim+0x42f/0x660 fs/jfs/jfs_discard.c:105
 jfs_ioctl+0x2b9/0x3d0 fs/jfs/ioctl.c:131
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7f8ef8f749
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:00007ffdf0517898 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f7f8f1e5fa0 RCX: 00007f7f8ef8f749
RDX: 0000200000000080 RSI: 00000000c0185879 RDI: 0000000000000004
RBP: 00007f7f8f013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7f8f1e5fa0 R14: 00007f7f8f1e5fa0 R15: 0000000000000003
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dbFindLeaf+0x517/0x520 fs/jfs/jfs_dmap.c:2983
Code: fe e9 51 ff ff ff e8 68 ea 87 fe 48 c7 c7 a0 cd e3 8a 48 c7 c6 e0 ca e3 8a ba a7 0b 00 00 48 c7 c1 80 d8 e3 8a e8 e9 84 5e 07 <0f> 0b 0f 1f 80 00 00 00 00 55 41 57 41 56 41 55 41 54 53 48 83 ec
RSP: 0018:ffffc900043afac0 EFLAGS: 00010246
RAX: 000000000000002b RBX: 00000000ffffffff RCX: d3219f4b2e11bc00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffc900043af7c7 R09: 1ffff92000875ef8
R10: dffffc0000000000 R11: fffff52000875ef9 R12: 0000000000000008
R13: 0000000000000060 R14: 000000000000005d R15: 0000000000000155
FS:  000055555edfd500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34463fff CR3: 000000002f5fe000 CR4: 00000000003506e0

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/20 05:49 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan kernel BUG in dbFindLeaf
2025/12/20 02:31 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan kernel BUG in dbFindLeaf
2025/12/20 01:45 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan kernel BUG in dbFindLeaf
2025/12/20 00:45 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan kernel BUG in dbFindLeaf
2026/01/11 06:11 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in dbFindLeaf
2026/01/06 10:40 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in dbFindLeaf
2026/01/04 17:03 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in dbFindLeaf
2025/12/28 13:47 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in dbFindLeaf
2025/12/19 23:48 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in dbFindLeaf
* Struck through repros no longer work on HEAD.