UBSAN: shift-out-of-bounds in dbDiscardAG (2)

Status: fixed on 2024/09/23 09:27
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+05b9907eabf0d95e5e80@syzkaller.appspotmail.com
Fix commit: 7063b80268e2 jfs: Fix shift-out-of-bounds in dbDiscardAG
First crash: 709d, last: 704d
Fix bisection: fixed by (bisect log) :
commit bd04a149e3a29e7f71b7956ed41dba34e42d539e
Author: Pei Li <peili.dev@gmail.com>
Date: Tue Jun 25 16:42:05 2024 +0000

  jfs: Fix shift-out-of-bounds in dbDiscardAG

  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2024/08/18 linux-6.1.y (ToT) 117ac406ba90 C [report] UBSAN: shift-out-of-bounds in dbDiscardAG
2024/08/18 upstream (ToT) ccdbf91fdf5a C Didn't crash
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 UBSAN: shift-out-of-bounds in dbDiscardAG origin:lts-only -1 C error 102 458d 711d 0/3 auto-obsoleted due to no activity on 2025/06/30 08:52
linux-6.1 UBSAN: shift-out-of-bounds in dbDiscardAG -1 1 1211d 1211d 0/3 auto-obsoleted due to no activity on 2023/07/28 02:34
upstream UBSAN: shift-out-of-bounds in dbDiscardAG jfs -1 C unreliable 5 747d 762d 27/29 fixed on 2024/08/14 03:44

Sample crash report:
loop0: detected capacity change from 0 to 32768
================================================================================
UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:1629:18
shift exponent -1 is negative
CPU: 1 PID: 3629 Comm: syz-executor368 Not tainted 6.1.105-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 ubsan_epilogue lib/ubsan.c:151 [inline]
 __ubsan_handle_shift_out_of_bounds+0x3bf/0x420 lib/ubsan.c:321
 dbDiscardAG+0x5a3/0xa10 fs/jfs/jfs_dmap.c:1629
 jfs_ioc_trim+0x42f/0x660 fs/jfs/jfs_discard.c:100
 jfs_ioctl+0x2cc/0x3e0 fs/jfs/ioctl.c:131
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6097013a79
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:00007ffddfb6c078 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f609705c05e RCX: 00007f6097013a79
RDX: 0000000020000180 RSI: 00000000c0185879 RDI: 0000000000000004
RBP: 00007f609708c610 R08: 0000000000000000 R09: 00007ffddfb6c248
R10: 0000000000006289 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffddfb6c238 R14: 0000000000000001 R15: 0000000000000001
 </TASK>
================================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/18 16:33 linux-6.1.y 117ac406ba90 dbc93b08 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan UBSAN: shift-out-of-bounds in dbDiscardAG
2024/08/13 23:54 linux-6.1.y 36790ef5e00b f21a18ca .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan UBSAN: shift-out-of-bounds in dbDiscardAG
2024/08/13 23:53 linux-6.1.y 36790ef5e00b f21a18ca .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan UBSAN: shift-out-of-bounds in dbDiscardAG
2024/08/13 22:03 linux-6.1.y 36790ef5e00b f21a18ca .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan UBSAN: shift-out-of-bounds in dbDiscardAG
2024/08/13 22:03 linux-6.1.y 36790ef5e00b f21a18ca .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan UBSAN: shift-out-of-bounds in dbDiscardAG
* Struck through repros no longer work on HEAD.