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

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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    cee73b1e840c Merge tag 'riscv-for-linus-7.0-mw1' of git://..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17ff615a580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6d9e410399043c26
dashboard link: https://syzkaller.appspot.com/bug?extid=a9747fe1c35a5b115d3f
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=131e86e6580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=171e86e6580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a804e6ee01e8/disk-cee73b1e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6bf476ceaefd/vmlinux-cee73b1e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bc7592aa375b/bzImage-cee73b1e.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/8dd42118c823/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a9747fe1c35a5b115d3f@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 8
Oops: general protection fault, probably for non-canonical address 0xe00fed1004f4f8aa: 0000 [#1] SMP KASAN NOPTI
KASAN: maybe wild-memory-access in range [0x007f888027a7c550-0x007f888027a7c557]
CPU: 1 UID: 0 PID: 5972 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:squashfs_copy_data+0xde/0x220 fs/squashfs/cache.c:308
Code: 74 08 4c 89 e7 e8 52 c8 91 ff 4c 63 fd 49 c1 ef 09 49 83 e7 f8 4d 03 3c 24 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ff e8 24 c8 91 ff 89 e8 25 ff 0f 00 00 4d
RSP: 0018:ffffc90002ee7430 EFLAGS: 00010216
RAX: 000ff11004f4f8aa RBX: 0000000000000000 RCX: dffffc0000000000
RDX: ffff88807ca88000 RSI: 0000000000000077 RDI: 00000000ffffe0fe
RBP: 00000000ffffe0fe R08: ffff888022a8df2b R09: 1ffff11004551be5
R10: dffffc0000000000 R11: ffffed1004551be6 R12: ffff88802a9f61a0
R13: 0000000000000077 R14: 000000000000000c R15: 007f888027a7c550
FS:  000055555fb6d500(0000) GS:ffff8881255a0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000057f000 CR3: 0000000030d9f000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 squashfs_read_metadata+0x193/0x6d0 fs/squashfs/cache.c:357
 squashfs_lookup+0x852/0xf20 fs/squashfs/namei.c:156
 __lookup_slow+0x2b7/0x410 fs/namei.c:1916
 lookup_slow+0x53/0x70 fs/namei.c:1933
 walk_component fs/namei.c:2279 [inline]
 link_path_walk+0xd1e/0x18d0 fs/namei.c:2647
 path_lookupat+0xe4/0x8c0 fs/namei.c:2803
 filename_lookup+0x256/0x5d0 fs/namei.c:2833
 kern_path+0x3d/0x150 fs/namei.c:3040
 unix_find_bsd net/unix/af_unix.c:1215 [inline]
 unix_find_other+0x197/0xac0 net/unix/af_unix.c:1277
 unix_dgram_connect+0x2cf/0xc20 net/unix/af_unix.c:1533
 __sys_connect_file net/socket.c:2089 [inline]
 __sys_connect+0x312/0x450 net/socket.c:2108
 __do_sys_connect net/socket.c:2114 [inline]
 __se_sys_connect net/socket.c:2111 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2111
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2536d9bf79
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffb506dda8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f2537015fa0 RCX: 00007f2536d9bf79
RDX: 000000000000006e RSI: 000020000057eff8 RDI: 0000000000000004
RBP: 00007f2536e327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2537015fac R14: 00007f2537015fa0 R15: 00007f2537015fa0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:squashfs_copy_data+0xde/0x220 fs/squashfs/cache.c:308
Code: 74 08 4c 89 e7 e8 52 c8 91 ff 4c 63 fd 49 c1 ef 09 49 83 e7 f8 4d 03 3c 24 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ff e8 24 c8 91 ff 89 e8 25 ff 0f 00 00 4d
RSP: 0018:ffffc90002ee7430 EFLAGS: 00010216
RAX: 000ff11004f4f8aa RBX: 0000000000000000 RCX: dffffc0000000000
RDX: ffff88807ca88000 RSI: 0000000000000077 RDI: 00000000ffffe0fe
RBP: 00000000ffffe0fe R08: ffff888022a8df2b R09: 1ffff11004551be5
R10: dffffc0000000000 R11: ffffed1004551be6 R12: ffff88802a9f61a0
R13: 0000000000000077 R14: 000000000000000c R15: 007f888027a7c550
FS:  000055555fb6d500(0000) GS:ffff8881254a0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f413658dd30 CR3: 0000000030d9f000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
   0:	74 08                	je     0xa
   2:	4c 89 e7             	mov    %r12,%rdi
   5:	e8 52 c8 91 ff       	call   0xff91c85c
   a:	4c 63 fd             	movslq %ebp,%r15
   d:	49 c1 ef 09          	shr    $0x9,%r15
  11:	49 83 e7 f8          	and    $0xfffffffffffffff8,%r15
  15:	4d 03 3c 24          	add    (%r12),%r15
  19:	4c 89 f8             	mov    %r15,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	4c 89 ff             	mov    %r15,%rdi
  33:	e8 24 c8 91 ff       	call   0xff91c85c
  38:	89 e8                	mov    %ebp,%eax
  3a:	25 ff 0f 00 00       	and    $0xfff,%eax
  3f:	4d                   	rex.WRB


---
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***

Subject: syzbot+a9747fe1c35a5b115d3f@syzkaller.appspotmail.com
Author: zlatistiv@gmail.com

#syz test