syzbot
UBSAN: shift-out-of-bounds in dbAllocAG (3)
Status:
upstream: reported C repro on 2025/10/17 04:35
Subsystems:
jfs
[Documentation on labels]
Reported-by: syzbot+4b717071f1eecb2972df@syzkaller.appspotmail.com
First crash: 285d, last: 192d
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✨ AI Jobs (6)
| ID |
Workflow |
Result |
Correct |
Bug |
Created |
Started |
Finished |
Revision |
Error |
| fd8b404a |
assessment-security |
|
💥 |
UBSAN: shift-out-of-bounds in dbAllocAG (3) |
2026/07/05 08:30 |
2026/07/05 08:30 |
2026/07/05 08:32 |
93f57954 |
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/ab0d0f43a7a9febdf5...
truncated to first 200 bytes; open job for full error
|
| 04fc7288 |
assessment-security |
|
💥 |
UBSAN: shift-out-of-bounds in dbAllocAG (3) |
2026/06/18 08:06 |
2026/06/18 08:06 |
2026/06/18 08:07 |
b62b3ded |
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/ab0d0f43a7a9febdf5...
truncated to first 200 bytes; open job for full error
|
| 09dcff7d |
assessment-security |
|
💥 |
UBSAN: shift-out-of-bounds in dbAllocAG (3) |
2026/06/10 03:54 |
2026/06/10 03:54 |
2026/06/10 03:57 |
c36c07f6 |
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/ab0d0f43a7a9febdf5...
truncated to first 200 bytes; open job for full error
|
| cc34fce1 |
assessment-security |
|
💥 |
UBSAN: shift-out-of-bounds in dbAllocAG (3) |
2026/06/04 06:54 |
2026/06/04 06:54 |
2026/06/04 06:56 |
62fe1528 |
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/ab0d0f43a7a9febdf5...
truncated to first 200 bytes; open job for full error
|
| b819b6f0 |
assessment-security |
|
💥 |
UBSAN: shift-out-of-bounds in dbAllocAG (3) |
2026/06/02 03:52 |
2026/06/02 03:52 |
2026/06/02 03:54 |
386cc6da |
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/ab0d0f43a7a9febdf5...
truncated to first 200 bytes; open job for full error
|
| c0f56205 |
assessment-security |
|
💥 |
UBSAN: shift-out-of-bounds in dbAllocAG (3) |
2026/05/21 15:45 |
2026/05/21 15:45 |
2026/05/21 15:48 |
d5742584 |
failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/ab0d0f43a7a9febdf5...
truncated to first 200 bytes; open job for full error
|
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Last patch testing requests (15)
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Fix bisection attempts (3)
Sample crash report:
------------[ cut here ]------------
UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:1440:48
shift exponent -1 is negative
CPU: 0 UID: 0 PID: 6076 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
ubsan_epilogue+0xa/0x40 lib/ubsan.c:233
__ubsan_handle_shift_out_of_bounds+0x386/0x410 lib/ubsan.c:494
dbAllocAG+0xfc0/0xff0 fs/jfs/jfs_dmap.c:1440
dbAlloc+0x5a8/0xba0 fs/jfs/jfs_dmap.c:877
extBalloc fs/jfs/jfs_extent.c:336 [inline]
extAlloc+0x54a/0xfb0 fs/jfs/jfs_extent.c:127
jfs_get_block+0x346/0xab0 fs/jfs/inode.c:254
__block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
block_write_begin+0x8a/0x120 fs/buffer.c:2256
jfs_write_begin+0x35/0x80 fs/jfs/inode.c:306
generic_perform_write+0x29d/0x8c0 mm/filemap.c:4242
generic_file_write_iter+0x118/0x550 mm/filemap.c:4385
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5d5/0xb40 fs/read_write.c:686
ksys_write+0x14b/0x260 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa99272eec9
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:00007fffa62c1048 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa992985fa0 RCX: 00007fa99272eec9
RDX: 0000000000000014 RSI: 0000200000000380 RDI: 0000000000000005
RBP: 00007fa9927b1f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa992985fa0 R14: 00007fa992985fa0 R15: 0000000000000003
</TASK>
---[ end trace ]---
Struck through repros no longer work on HEAD.