syzbot


UBSAN: shift-out-of-bounds in squashfs_bio_read

Status: upstream: reported C repro on 2025/04/05 07:36
Subsystems: squashfs
[Documentation on labels]
Reported-by: syzbot+65761fc25a137b9c8c6e@syzkaller.appspotmail.com
First crash: 6d18h, last: 1d22h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [squashfs?] UBSAN: shift-out-of-bounds in squashfs_bio_read 1 (3) 2025/04/07 05:30

Sample crash report:
loop0: detected capacity change from 0 to 8
------------[ cut here ]------------
UBSAN: shift-out-of-bounds in fs/squashfs/block.c:195:36
shift exponent 64 is too large for 64-bit type 'u64' (aka 'unsigned long long')
CPU: 0 UID: 0 PID: 5472 Comm: syz-executor224 Not tainted 6.14.0-syzkaller-13443-g56f944529ec2 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_shift_out_of_bounds+0x3c8/0x420 lib/ubsan.c:492
 squashfs_bio_read+0xf7e/0x10b0 fs/squashfs/block.c:195
 squashfs_read_data+0x2e7/0xba0 fs/squashfs/block.c:333
 squashfs_read_table+0x338/0x390 fs/squashfs/cache.c:436
 squashfs_fill_super+0x238/0x21e0 fs/squashfs/super.c:216
 get_tree_bdev_flags+0x490/0x5c0 fs/super.c:1636
 vfs_get_tree+0x90/0x2b0 fs/super.c:1759
 do_new_mount+0x2cf/0xb70 fs/namespace.c:3879
 do_mount fs/namespace.c:4219 [inline]
 __do_sys_mount fs/namespace.c:4430 [inline]
 __se_sys_mount+0x38c/0x400 fs/namespace.c:4407
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbefca8001a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007ffcb4b512c8 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffcb4b512e0 RCX: 00007fbefca8001a
RDX: 0000200000000240 RSI: 0000200000000280 RDI: 00007ffcb4b512e0
RBP: 0000200000000280 R08: 00007ffcb4b51320 R09: 0000000000000220
R10: 0000000000000000 R11: 0000000000000282 R12: 0000200000000240
R13: 00007ffcb4b51320 R14: 0000000000000003 R15: 0000000000000000
 </TASK>
---[ end trace ]---

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/06 03:37 upstream 56f944529ec2 1c65791e .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root UBSAN: shift-out-of-bounds in squashfs_bio_read
2025/04/01 07:29 upstream 609706855d90 36d76a97 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root UBSAN: shift-out-of-bounds in squashfs_bio_read
2025/04/06 03:12 upstream 56f944529ec2 1c65791e .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root UBSAN: shift-out-of-bounds in squashfs_bio_read
* Struck through repros no longer work on HEAD.