[syzbot] [squashfs?] general protection fault in squashfs_page_actor_init_special

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syzbot

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Apr 18, 2023, 2:46:54 AM4/18/23
to linux-...@vger.kernel.org, linux-...@vger.kernel.org, phi...@squashfs.org.uk, squashf...@lists.sourceforge.net, syzkall...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: de4664485abb Merge tag 'for-linus-2023041201' of git://git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16bc4a33c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=759d5e665e47a55
dashboard link: https://syzkaller.appspot.com/bug?extid=8b3f7f31f049832f24f8
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/44a61f522288/disk-de466448.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d98783cb3e58/vmlinux-de466448.xz
kernel image: https://storage.googleapis.com/syzbot-assets/72cf36ebe961/bzImage-de466448.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8b3f7f...@syzkaller.appspotmail.com

loop2: detected capacity change from 0 to 8
SQUASHFS error: Failed to read block 0x4ba: -5
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 PID: 16271 Comm: syz-executor.2 Not tainted 6.3.0-rc6-syzkaller-00046-gde4664485abb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
RIP: 0010:squashfs_page_actor_init_special+0x20e/0x4c0 fs/squashfs/page_actor.c:128
Code: 00 00 00 49 8d 6c 24 48 48 89 e8 48 c1 e8 03 42 0f b6 04 30 84 c0 0f 85 32 02 00 00 c7 45 00 00 00 00 00 4c 89 f8 48 c1 e8 03 <42> 80 3c 30 00 74 08 4c 89 ff e8 23 16 8e ff 49 8b 2f 48 83 c5 20
RSP: 0018:ffffc90005e865d8 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 0000000000001000 RCX: 0000000000040000
RDX: ffff88802a419d40 RSI: 0000000000001000 RDI: ffff88802f3596c0
RBP: ffff88802f3596c8 R08: ffffffff825212b3 R09: fffffbfff205b664
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88802f359680
R13: 0000000000001000 R14: dffffc0000000000 R15: 0000000000000010
FS: 00007fbcca418700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f29ab2d7000 CR3: 0000000023f35000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
squashfs_readpage_block+0x634/0xf80 fs/squashfs/file_direct.c:70
squashfs_read_folio+0x569/0xee0 fs/squashfs/file.c:479
filemap_read_folio+0x19d/0x7a0 mm/filemap.c:2424
filemap_update_page mm/filemap.c:2508 [inline]
filemap_get_pages+0x15a5/0x20c0 mm/filemap.c:2622
filemap_read+0x45a/0x1170 mm/filemap.c:2693
__kernel_read+0x422/0x8a0 fs/read_write.c:428
integrity_kernel_read+0xb0/0xf0 security/integrity/iint.c:199
ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:485 [inline]
ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline]
ima_calc_file_hash+0xa5b/0x1c00 security/integrity/ima/ima_crypto.c:573
ima_collect_measurement+0x3a7/0x880 security/integrity/ima/ima_api.c:293
process_measurement+0xfdb/0x1ce0 security/integrity/ima/ima_main.c:341
ima_file_check+0xf1/0x170 security/integrity/ima/ima_main.c:539
do_open fs/namei.c:3562 [inline]
path_openat+0x280a/0x3170 fs/namei.c:3715
do_filp_open+0x234/0x490 fs/namei.c:3742
do_sys_openat2+0x13f/0x500 fs/open.c:1348
do_sys_open fs/open.c:1364 [inline]
__do_sys_open fs/open.c:1372 [inline]
__se_sys_open fs/open.c:1368 [inline]
__x64_sys_open+0x225/0x270 fs/open.c:1368
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fbcc968c169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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:00007fbcca418168 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fbcc97abf80 RCX: 00007fbcc968c169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020002a00
RBP: 00007fbcc96e7ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd54b3d52f R14: 00007fbcca418300 R15: 0000000000022000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:squashfs_page_actor_init_special+0x20e/0x4c0 fs/squashfs/page_actor.c:128
Code: 00 00 00 49 8d 6c 24 48 48 89 e8 48 c1 e8 03 42 0f b6 04 30 84 c0 0f 85 32 02 00 00 c7 45 00 00 00 00 00 4c 89 f8 48 c1 e8 03 <42> 80 3c 30 00 74 08 4c 89 ff e8 23 16 8e ff 49 8b 2f 48 83 c5 20
RSP: 0018:ffffc90005e865d8 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 0000000000001000 RCX: 0000000000040000
RDX: ffff88802a419d40 RSI: 0000000000001000 RDI: ffff88802f3596c0
RBP: ffff88802f3596c8 R08: ffffffff825212b3 R09: fffffbfff205b664
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88802f359680
R13: 0000000000001000 R14: dffffc0000000000 R15: 0000000000000010
FS: 00007fbcca418700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f822f208fc0 CR3: 0000000023f35000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 49 8d add %cl,-0x73(%rcx)
5: 6c insb (%dx),%es:(%rdi)
6: 24 48 and $0x48,%al
8: 48 89 e8 mov %rbp,%rax
b: 48 c1 e8 03 shr $0x3,%rax
f: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax
14: 84 c0 test %al,%al
16: 0f 85 32 02 00 00 jne 0x24e
1c: c7 45 00 00 00 00 00 movl $0x0,0x0(%rbp)
23: 4c 89 f8 mov %r15,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 ff mov %r15,%rdi
34: e8 23 16 8e ff callq 0xff8e165c
39: 49 8b 2f mov (%r15),%rbp
3c: 48 83 c5 20 add $0x20,%rbp


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syzbot

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Aug 11, 2023, 8:41:41 PM8/11/23
to syzkall...@googlegroups.com
Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.
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