WARNING in squashfs_read_table

From: syzbot
Date: Sat Jan 09 2021 - 19:00:45 EST


Hello,

syzbot found the following issue on:

HEAD commit: 83dadd4c Add linux-next specific files for 20210105
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14c0532b500000
kernel config: https://syzkaller.appspot.com/x/.config?x=ca68c01770b963e1
dashboard link: https://syzkaller.appspot.com/bug?extid=2ccea6339d368360800d
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=115f4dfb500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1542c43f500000

Bisection is inconclusive: the issue happens on the oldest tested release.

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17f77b67500000
final oops: https://syzkaller.appspot.com/x/report.txt?x=140f7b67500000
console output: https://syzkaller.appspot.com/x/log.txt?x=100f7b67500000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2ccea6339d368360800d@xxxxxxxxxxxxxxxxxxxxxxxxx

loop0: detected capacity change from 8 to 0
------------[ cut here ]------------
WARNING: CPU: 0 PID: 8456 at mm/page_alloc.c:4977 __alloc_pages_nodemask+0x5f8/0x730 mm/page_alloc.c:5012
Modules linked in:
CPU: 0 PID: 8456 Comm: syz-executor943 Not tainted 5.11.0-rc2-next-20210105-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__alloc_pages_nodemask+0x5f8/0x730 mm/page_alloc.c:4977
Code: 00 00 0c 00 0f 85 a7 00 00 00 8b 3c 24 4c 89 f2 44 89 e6 c6 44 24 70 00 48 89 6c 24 58 e8 d0 d7 ff ff 49 89 c5 e9 ea fc ff ff <0f> 0b e9 b5 fd ff ff 89 74 24 14 4c 89 4c 24 08 4c 89 74 24 18 e8
RSP: 0018:ffffc9000112fa98 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff92000225f57 RCX: 0000000000000000
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000040cc0
RBP: 0000000000040cc0 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81b25651 R11: 0000000000000000 R12: 0000000000000034
R13: 0000000000000034 R14: 0000000000000000 R15: 00000000e24d8401
FS: 00000000019a2880(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000559ed1ff3180 CR3: 000000001b421000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
alloc_pages_current+0x18c/0x2a0 mm/mempolicy.c:2267
alloc_pages include/linux/gfp.h:547 [inline]
kmalloc_order+0x2e/0xb0 mm/slab_common.c:916
kmalloc_order_trace+0x14/0x120 mm/slab_common.c:932
kmalloc include/linux/slab.h:559 [inline]
squashfs_read_table+0x43/0x1e0 fs/squashfs/cache.c:413
squashfs_read_xattr_id_table+0x191/0x220 fs/squashfs/xattr_id.c:81
squashfs_fill_super+0xcfb/0x23b0 fs/squashfs/super.c:225
get_tree_bdev+0x421/0x740 fs/super.c:1291
vfs_get_tree+0x89/0x2f0 fs/super.c:1496
do_new_mount fs/namespace.c:2899 [inline]
path_mount+0x12ae/0x1e70 fs/namespace.c:3230
do_mount fs/namespace.c:3243 [inline]
__do_sys_mount fs/namespace.c:3451 [inline]
__se_sys_mount fs/namespace.c:3428 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3428
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x446d1a
Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 fd ad fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 da ad fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007ffe89cbd7b8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffe89cbd810 RCX: 0000000000446d1a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffe89cbd7d0
RBP: 00007ffe89cbd7d0 R08: 00007ffe89cbd810 R09: 00007ffe00000015
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 0000000000000004 R14: 0000000000000003 R15: 0000000000000003


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches