UBSAN: array-index-out-of-bounds in dbAllocBits

Status: upstream: reported C repro on 2023/05/19 04:28
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+fc68ece19701d9c7f9d4@syzkaller.appspotmail.com
First crash: 1272d, last: 304d
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2024/07/01 upstream (ToT) 22a40d14b572 C [report] UBSAN: array-index-out-of-bounds in dbAllocBits
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream UBSAN: array-index-out-of-bounds in dbAllocBits jfs 19 syz, C inconclusive error 234 1048d 1499d 0/29 auto-obsoleted due to no activity on 2024/03/07 21:48
linux-5.15 UBSAN: array-index-out-of-bounds in dbAllocBits origin:upstream 15 syz, C error 5 35d 1272d 0/3 upstream: reported C repro on 2023/05/19 07:30
upstream KASAN: slab-out-of-bounds Read in dbAllocBits jfs prio:high 17 syz, C error error 315 2d13h 916d 0/29 upstream: reported C repro on 2024/05/09 13:18
linux-6.6 UBSAN: array-index-out-of-bounds in dbAllocBits origin:upstream 15 syz, C error 1 248d 248d 0/2 upstream: reported C repro on 2026/03/08 09:25
linux-4.19 KASAN: use-after-free Read in dbAllocBits 19 syz, C error 2 1480d 1502d 0/1 upstream: reported C repro on 2022/10/01 12:57
▶ ▼ Fix bisection attempts (14)
Created Duration User Patch Repo Result
2024/10/15 02:28 0m bisect fix linux-6.1.y error job log
2024/09/13 13:14 1h08m bisect fix linux-6.1.y OK (0) job log log
2024/08/12 13:56 2h00m bisect fix linux-6.1.y OK (0) job log log
2024/07/01 04:01 1h07m bisect fix linux-6.1.y OK (0) job log log
2024/05/23 00:30 1h14m bisect fix linux-6.1.y OK (0) job log log
2024/04/18 22:34 2h21m bisect fix linux-6.1.y OK (0) job log log
2024/03/16 08:15 1h41m bisect fix linux-6.1.y OK (0) job log log
2024/02/10 21:34 1h49m bisect fix linux-6.1.y OK (0) job log log
2024/01/04 02:05 1h22m bisect fix linux-6.1.y OK (0) job log log
2023/12/04 23:44 1h16m bisect fix linux-6.1.y OK (0) job log log
2023/11/04 11:51 1h35m bisect fix linux-6.1.y OK (0) job log log
2023/10/04 00:47 1h23m bisect fix linux-6.1.y OK (0) job log log
2023/08/09 13:36 4h05m bisect fix linux-6.1.y OK (0) job log log
2023/06/19 03:48 58m bisect fix linux-6.1.y OK (0) job log log

Sample crash report:
loop0: detected capacity change from 0 to 32768
================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:2238:2
index 2000 is out of range for type 's64[128]' (aka 'long long[128]')
CPU: 1 PID: 3542 Comm: syz-executor191 Not tainted 6.1.34-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
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_out_of_bounds+0x118/0x140 lib/ubsan.c:282
 dbAllocBits+0x961/0x990 fs/jfs/jfs_dmap.c:2238
 dbAllocDmap fs/jfs/jfs_dmap.c:2015 [inline]
 dbAllocNear+0x262/0x390 fs/jfs/jfs_dmap.c:1244
 dbAlloc+0xa1f/0xc90 fs/jfs/jfs_dmap.c:829
 ea_get+0x9b5/0x1280 fs/jfs/xattr.c:514
 __jfs_setxattr+0x4b6/0x11d0 fs/jfs/xattr.c:718
 __jfs_set_acl+0x12a/0x1b0 fs/jfs/acl.c:87
 jfs_set_acl+0x2a9/0x550 fs/jfs/acl.c:114
 set_posix_acl fs/posix_acl.c:1160 [inline]
 posix_acl_xattr_set+0x37b/0x3e0 fs/posix_acl.c:1189
 __vfs_setxattr+0x3e7/0x420 fs/xattr.c:182
 __vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216
 vfs_setxattr+0x21d/0x420 fs/xattr.c:309
 do_setxattr fs/xattr.c:594 [inline]
 setxattr+0x250/0x2b0 fs/xattr.c:617
 path_setxattr+0x1bc/0x2a0 fs/xattr.c:636
 __do_sys_lsetxattr fs/xattr.c:659 [inline]
 __se_sys_lsetxattr fs/xattr.c:655 [inline]
 __x64_sys_lsetxattr+0xb4/0xd0 fs/xattr.c:655
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f0b26dcd849
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe4c4871d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f0b26dcd849
RDX: 0000000020000180 RSI: 0000000020000040 RDI: 0000000020000000
RBP: 00007f0b26d8d0e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000024 R11: 0000000000000246 R12: 00007f0b26d8d170
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
================================================================================

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/06/19 12:10 linux-6.1.y ca87e77a2ef8 f3921d4d .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan UBSAN: array-index-out-of-bounds in dbAllocBits
2023/05/19 04:28 linux-6.1.y fa74641fb6b9 3bb7af1d .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 UBSAN: array-index-out-of-bounds in dbAllocBits
2026/01/04 01:48 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan UBSAN: array-index-out-of-bounds in dbAllocBits
2026/01/11 02:15 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: array-index-out-of-bounds in dbAllocBits
* Struck through repros no longer work on HEAD.