syzbot


UBSAN: shift-out-of-bounds in minix_count_free_blocks

Status: upstream: reported C repro on 2022/02/24 22:40
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+2f142b57f2af27974fda@syzkaller.appspotmail.com
First crash: 850d, last: 182d
Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: UBSAN: shift-out-of-bounds in minix_count_free_blocks (log)
Repro: C syz .config
  
Fix bisection the fix commit could be any of (bisect log):
  e8a4e1c1bb69 Merge tag 'loongarch-fixes-5.19-4' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
  1612c382ffbd Merge tag 'x86-urgent-2022-08-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
  
Discussions (3)
Title Replies (including bot) Last reply
[PATCH] fs/minix: Improve validity checking of superblock 2 (2) 2023/10/12 11:45
[PATCH] fs/minix: Improve validity checking of superblock 1 (1) 2023/10/02 18:11
[syzbot] UBSAN: shift-out-of-bounds in minix_count_free_blocks 0 (1) 2022/02/24 22:40
Last patch testing requests (13)
Created Duration User Patch Repo Result
2024/04/30 21:01 15m retest repro linux-next error OK
2024/03/04 23:50 23m retest repro upstream OK log
2024/02/19 21:25 22m retest repro linux-next error OK
2024/02/19 04:22 21m retest repro upstream OK log
2024/01/09 15:41 24m retest repro upstream OK log
2024/01/09 15:21 20m retest repro upstream OK log
2023/12/25 03:03 15m retest repro upstream report log
2023/12/11 01:44 14m retest repro upstream report log
2023/12/11 01:44 1h04m retest repro linux-next error OK
2023/10/31 09:51 1h02m retest repro upstream report log
2022/05/10 02:55 8m wanngchenng@gmail.com https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ master report log
2022/05/01 01:40 8m (218) wanngchenng@gmail.com https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ master report log
2022/04/30 10:12 10m (218) wanngchenng@gmail.com https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ master report log
Fix bisection attempts (5)
Created Duration User Patch Repo Result
2022/08/07 05:42 20m bisect fix upstream job log (2)
2022/06/26 08:57 21m bisect fix upstream job log (0) log
2022/05/25 12:09 18m bisect fix upstream job log (0) log
2022/04/25 09:02 18m bisect fix upstream job log (0) log
2022/03/26 08:42 19m bisect fix upstream job log (0) log

Sample crash report:
loop0: detected capacity change from 0 to 24
 loop0: unable to read partition table
loop0: partition table beyond EOD, truncated
MINIX-fs: mounting unchecked file system, running fsck is recommended
================================================================================
UBSAN: shift-out-of-bounds in fs/minix/bitmap.c:103:3
shift exponent 34 is too large for 32-bit type 'unsigned int'
CPU: 0 PID: 3607 Comm: syz-executor123 Not tainted 5.19.0-rc4-next-20220628-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 ubsan_epilogue+0xb/0x50 lib/ubsan.c:151
 __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x187 lib/ubsan.c:322
 minix_count_free_blocks.cold+0x16/0x1b fs/minix/bitmap.c:103
 minix_statfs+0x22a/0x490 fs/minix/inode.c:381
 statfs_by_dentry+0x133/0x210 fs/statfs.c:66
 vfs_statfs fs/statfs.c:90 [inline]
 user_statfs+0xa9/0x160 fs/statfs.c:105
 __do_sys_statfs+0x7a/0xf0 fs/statfs.c:195
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7fd106612dc9
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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd88350828 EFLAGS: 00000246 ORIG_RAX: 0000000000000089
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007fd106612dc9
RDX: 00007fd1065d12f3 RSI: 0000000000000000 RDI: 0000000020000140
RBP: 00007fd1065d25c0 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffd883506f0 R11: 0000000000000246 R12: 00007fd1065d2650
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
================================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/07/05 02:06 linux-next cb71b93c2dc3 bff65f44 .config strace log report syz C ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in minix_count_free_blocks
2022/08/07 05:45 upstream 200e340f2196 88e3a122 .config strace log report syz C ci-upstream-kasan-gce-selinux-root UBSAN: shift-out-of-bounds in minix_count_free_blocks
2022/07/08 05:42 upstream e8a4e1c1bb69 bff65f44 .config strace log report syz C ci-upstream-kasan-gce-smack-root UBSAN: shift-out-of-bounds in minix_count_free_blocks
2022/02/24 08:42 upstream 23d04328444a 6e821dbf .config console log report syz C ci-upstream-kasan-gce-root UBSAN: shift-out-of-bounds in minix_count_free_blocks
2022/02/24 08:28 upstream 23d04328444a 6e821dbf .config console log report info ci-upstream-kasan-gce-root UBSAN: shift-out-of-bounds in minix_count_free_blocks
2022/02/24 08:42 upstream 23d04328444a 6e821dbf .config console log report info ci-qemu-upstream-386 UBSAN: shift-out-of-bounds in minix_count_free_blocks
* Struck through repros no longer work on HEAD.