UBSAN: shift-out-of-bounds in dbSplit

Status: fixed on 2025/01/09 09:39
Reported-by: syzbot+dde611e78c1b7981727a@syzkaller.appspotmail.com
Fix commit: a5f5e4698f8a jfs: fix shift-out-of-bounds in dbSplit
First crash: 833d, last: 616d
Fix bisection: fixed by (bisect log) :
commit 51a203470f502a64a3da8dcea51c4748e8267a6c
Author: Ghanshyam Agrawal <ghanshyam1898@gmail.com>
Date: Mon Sep 30 08:12:18 2024 +0000

  jfs: fix shift-out-of-bounds in dbSplit

  
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2024/12/19 upstream (ToT) eabcdba3ad40 C Didn't crash
▶ ▼ 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 C error 1 438d 505d 0/3 upstream: reported C repro on 2025/03/09 22:23
upstream UBSAN: shift-out-of-bounds in dbSplit (2) jfs -1 C error 403 601d 847d 28/29 fixed on 2024/12/16 09:50
upstream UBSAN: shift-out-of-bounds in dbSplit jfs -1 C error done 7 938d 1392d 25/29 fixed on 2024/02/09 18:10
upstream UBSAN: shift-out-of-bounds in dbSplit (3) jfs -1 C 8 138d 453d 29/29 fixed on 2026/05/21 07:50
linux-5.15 UBSAN: shift-out-of-bounds in dbSplit origin:upstream -1 C error 36 65d 833d 0/3 upstream: reported C repro on 2024/04/15 22:09
▶ ▼ Fix bisection attempts (6)
Created Duration User Patch Repo Result
2025/01/05 17:11 6h52m bisect fix linux-6.1.y OK (1) job log
2024/11/18 17:34 1h19m bisect fix linux-6.1.y OK (0) job log log
2024/10/14 18:41 1h49m bisect fix linux-6.1.y OK (0) job log log
2024/08/28 01:11 2h05m bisect fix linux-6.1.y OK (0) job log log
2024/07/20 18:32 1h55m bisect fix linux-6.1.y OK (0) job log log
2024/06/04 11:31 1h29m bisect fix linux-6.1.y OK (0) job log log

Sample crash report:
loop3: detected capacity change from 0 to 32768
================================================================================
UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:2639:11
shift exponent 80 is too large for 32-bit type 'int'
CPU: 1 PID: 7433 Comm: syz-executor.3 Not tainted 6.1.89-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
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
 dbSplit+0x21a/0x220 fs/jfs/jfs_dmap.c:2639
 dbAllocBits+0x4e5/0x9a0 fs/jfs/jfs_dmap.c:2191
 dbAllocDmap fs/jfs/jfs_dmap.c:2032 [inline]
 dbAllocDmapLev+0x24c/0x490 fs/jfs/jfs_dmap.c:1986
 dbAllocCtl+0x113/0x920 fs/jfs/jfs_dmap.c:1823
 dbAllocAG+0x28b/0x10b0 fs/jfs/jfs_dmap.c:1364
 dbAlloc+0x654/0xc90 fs/jfs/jfs_dmap.c:888
 dtSplitUp fs/jfs/jfs_dtree.c:979 [inline]
 dtInsert+0xda3/0x6b00 fs/jfs/jfs_dtree.c:868
 jfs_symlink+0x823/0x10e0 fs/jfs/namei.c:1019
 vfs_symlink+0x247/0x3d0 fs/namei.c:4473
 do_symlinkat+0x21e/0x390 fs/namei.c:4502
 __do_sys_symlinkat fs/namei.c:4519 [inline]
 __se_sys_symlinkat fs/namei.c:4516 [inline]
 __x64_sys_symlinkat+0x95/0xa0 fs/namei.c:4516
 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: 0033:0x7f5ff1a7dea9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5ff281a0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007f5ff1babf80 RCX: 00007f5ff1a7dea9
RDX: 0000000020000340 RSI: 0000000000000004 RDI: 0000000020000440
RBP: 00007f5ff1aca4a4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f5ff1babf80 R15: 00007ffd66a88a98
 </TASK>
================================================================================

Crashes (18):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/30 08:29 linux-6.1.y dcbc050cb0d3 f10afd69 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan UBSAN: shift-out-of-bounds in dbSplit
2024/04/15 22:34 linux-6.1.y cd5d98c0556c b9af7e61 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan UBSAN: shift-out-of-bounds in dbSplit
2024/04/15 22:10 linux-6.1.y cd5d98c0556c b9af7e61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan UBSAN: shift-out-of-bounds in dbSplit
2024/06/06 18:02 linux-6.1.y 88690811da69 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
2024/05/03 01:56 linux-6.1.y 909ba1f1b414 ddfc15a1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
2024/05/03 01:51 linux-6.1.y 909ba1f1b414 ddfc15a1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
2024/05/02 16:24 linux-6.1.y 909ba1f1b414 3ba885bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
2024/05/02 16:24 linux-6.1.y 909ba1f1b414 3ba885bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
2024/05/02 03:45 linux-6.1.y dcbc050cb0d3 3ba885bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
2024/05/01 04:18 linux-6.1.y dcbc050cb0d3 3ba885bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
2024/05/01 03:30 linux-6.1.y dcbc050cb0d3 3ba885bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
2024/04/30 16:13 linux-6.1.y dcbc050cb0d3 3ce4924c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
2024/04/30 15:11 linux-6.1.y dcbc050cb0d3 3ce4924c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
2024/04/30 15:11 linux-6.1.y dcbc050cb0d3 3ce4924c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
2024/04/30 08:35 linux-6.1.y dcbc050cb0d3 f10afd69 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
2024/04/30 08:32 linux-6.1.y dcbc050cb0d3 f10afd69 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
2024/04/15 22:42 linux-6.1.y cd5d98c0556c b9af7e61 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
2024/04/15 22:10 linux-6.1.y cd5d98c0556c b9af7e61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 UBSAN: shift-out-of-bounds in dbSplit
* Struck through repros no longer work on HEAD.