[syzbot] general protection fault in bio_free

syzbot
2022-03-31T16:53:39Z

Hello,

syzbot found the following issue on:

HEAD commit: fdcbcd1348f4 Add linux-next specific files for 20220331
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1583bdb9700000
kernel config: https://syzkaller.appspot.com/x/.config?x=366ab475940a4177
dashboard link: https://syzkaller.appspot.com/bug?extid=51175d2754e4b4c04d6d
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+51175d2754e4b4c04d6d@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 PID: 3906 Comm: syz-executor.2 Not tainted 5.17.0-next-20220331-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:bio_free+0xc3/0x120 block/bio.c:233
Code: 6e 48 8b 73 78 48 8d bd d0 00 00 00 e8 46 fe ff ff 48 8d 7d 08 48 b8 00 00 00 00 00 fc ff df 48 8d 75 18 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 3c 03 7e 20 8b 45 08 48 83 c4 08 48 29 c3
RSP: 0018:ffffc9000528fac0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88807c8c5c00 RCX: ffffc9000c212000
RDX: 0000000000000001 RSI: 0000000000000018 RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff83d576a5 R11: 0000000000000004 R12: 0000000000000060
R13: 0000000000000060 R14: 0000000000001000 R15: 0000000000000060
FS: 00007f068de1f700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555631d848 CR3: 0000000077fb2000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
bio_put+0x20e/0x3b0 block/bio.c:754
squashfs_read_data+0x2ce/0xed0 fs/squashfs/block.c:221
squashfs_read_table+0x184/0x1f0 fs/squashfs/cache.c:432
squashfs_fill_super+0x337/0x2690 fs/squashfs/super.c:184
get_tree_bdev+0x440/0x760 fs/super.c:1292
vfs_get_tree+0x89/0x2f0 fs/super.c:1497
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x1320/0x1fa0 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f068cc8a57a
Code: 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 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:00007f068de1ef88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007f068cc8a57a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f068de1efe0
RBP: 00007f068de1f020 R08: 00007f068de1f020 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000
R13: 0000000020000100 R14: 00007f068de1efe0 R15: 0000000020000140
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:bio_free+0xc3/0x120 block/bio.c:233
Code: 6e 48 8b 73 78 48 8d bd d0 00 00 00 e8 46 fe ff ff 48 8d 7d 08 48 b8 00 00 00 00 00 fc ff df 48 8d 75 18 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 3c 03 7e 20 8b 45 08 48 83 c4 08 48 29 c3
RSP: 0018:ffffc9000528fac0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88807c8c5c00 RCX: ffffc9000c212000
RDX: 0000000000000001 RSI: 0000000000000018 RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff83d576a5 R11: 0000000000000004 R12: 0000000000000060
R13: 0000000000000060 R14: 0000000000001000 R15: 0000000000000060
FS: 00007f068de1f700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557421b87a30 CR3: 0000000077fb2000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 6e outsb %ds:(%rsi),(%dx)
1: 48 8b 73 78 mov 0x78(%rbx),%rsi
5: 48 8d bd d0 00 00 00 lea 0xd0(%rbp),%rdi
c: e8 46 fe ff ff callq 0xfffffe57
11: 48 8d 7d 08 lea 0x8(%rbp),%rdi
15: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
1c: fc ff df
1f: 48 8d 75 18 lea 0x18(%rbp),%rsi
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction
2e: 84 c0 test %al,%al
30: 74 04 je 0x36
32: 3c 03 cmp $0x3,%al
34: 7e 20 jle 0x56
36: 8b 45 08 mov 0x8(%rbp),%eax
39: 48 83 c4 08 add $0x8,%rsp
3d: 48 29 c3 sub %rax,%rbx

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