Hello,
syzbot found the following issue on:
HEAD commit: 31acccdc Linux 4.19.157
git tree: linux-4.19.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=160f1bba500000
kernel config:
https://syzkaller.appspot.com/x/.config?x=1f604e014c43fe09
dashboard link:
https://syzkaller.appspot.com/bug?extid=b06d57ba83f604522af2
compiler: gcc (GCC) 10.1.0-syz 20200507
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:
[email protected]
==================================================================
BUG: KASAN: use-after-free in squashfs_get_id+0x1ae/0x1d0 fs/squashfs/id.c:51
Read of size 8 at addr ffff888096c3a840 by task syz-executor.0/10828
CPU: 1 PID: 10828 Comm: syz-executor.0 Not tainted 4.19.157-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2fe lib/dump_stack.c:118
print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354
kasan_report mm/kasan/report.c:412 [inline]
__asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
squashfs_get_id+0x1ae/0x1d0 fs/squashfs/id.c:51
squashfs_new_inode fs/squashfs/inode.c:64 [inline]
squashfs_read_inode+0x1b4/0x1b40 fs/squashfs/inode.c:133
squashfs_fill_super+0x1655/0x1c00 fs/squashfs/super.c:318
mount_bdev+0x2fc/0x3b0 fs/super.c:1158
mount_fs+0xa3/0x30c fs/super.c:1261
vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
vfs_kern_mount fs/namespace.c:951 [inline]
do_new_mount fs/namespace.c:2469 [inline]
do_mount+0x113c/0x2f10 fs/namespace.c:2799
ksys_mount+0xcf/0x130 fs/namespace.c:3015
__do_sys_mount fs/namespace.c:3029 [inline]
__se_sys_mount fs/namespace.c:3026 [inline]
__x64_sys_mount+0xba/0x150 fs/namespace.c:3026
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x46090a
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 ad 89 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 8a 89 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007f1dcede8a88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f1dcede8b20 RCX: 000000000046090a
RDX: 0000000020000000 RSI: 00000000200000c0 RDI: 00007f1dcede8ae0
RBP: 00007f1dcede8ae0 R08: 00007f1dcede8b20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 00000000200000c0 R14: 0000000020000200 R15: 0000000020010200
Allocated by task 9837:
__do_kmalloc mm/slab.c:3727 [inline]
__kmalloc+0x15a/0x3c0 mm/slab.c:3736
kmalloc_array include/linux/slab.h:637 [inline]
kcalloc include/linux/slab.h:648 [inline]
squashfs_cache_init+0x3a6/0x740 fs/squashfs/cache.c:271
squashfs_fill_super+0xa94/0x1c00 fs/squashfs/super.c:204
mount_bdev+0x2fc/0x3b0 fs/super.c:1158
mount_fs+0xa3/0x30c fs/super.c:1261
vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
vfs_kern_mount fs/namespace.c:951 [inline]
do_new_mount fs/namespace.c:2469 [inline]
do_mount+0x113c/0x2f10 fs/namespace.c:2799
ksys_mount+0xcf/0x130 fs/namespace.c:3015
__do_sys_mount fs/namespace.c:3029 [inline]
__se_sys_mount fs/namespace.c:3026 [inline]
__x64_sys_mount+0xba/0x150 fs/namespace.c:3026
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 9837:
__cache_free mm/slab.c:3503 [inline]
kfree+0xcc/0x210 mm/slab.c:3822
squashfs_cache_delete.part.0+0x248/0x370 fs/squashfs/cache.c:221
squashfs_cache_delete+0x1b/0x30 fs/squashfs/cache.c:214
squashfs_fill_super+0x248/0x1c00 fs/squashfs/super.c:338
mount_bdev+0x2fc/0x3b0 fs/super.c:1158
mount_fs+0xa3/0x30c fs/super.c:1261
vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
vfs_kern_mount fs/namespace.c:951 [inline]
do_new_mount fs/namespace.c:2469 [inline]
do_mount+0x113c/0x2f10 fs/namespace.c:2799
ksys_mount+0xcf/0x130 fs/namespace.c:3015
__do_sys_mount fs/namespace.c:3029 [inline]
__se_sys_mount fs/namespace.c:3026 [inline]
__x64_sys_mount+0xba/0x150 fs/namespace.c:3026
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff888096c3a840
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
32-byte region [ffff888096c3a840, ffff888096c3a860)
The buggy address belongs to the page:
page:ffffea00025b0e80 count:1 mapcount:0 mapping:ffff88813bff01c0 index:0xffff888096c3afc1
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea0002cf6a48 ffffea0002a58f48 ffff88813bff01c0
raw: ffff888096c3afc1 ffff888096c3a000 0000000100000038 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888096c3a700: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
ffff888096c3a780: 00 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
>ffff888096c3a800: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
^
ffff888096c3a880: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
ffff888096c3a900: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================
squashfs: SQUASHFS error: Filesystem uses "lzma" compression. This is not supported
SQUASHFS error: squashfs_read_data failed to read block 0x6081
SQUASHFS error: Unable to read metadata cache entry [6081]
SQUASHFS error: Unable to read inode 0x6000011a
squashfs: SQUASHFS error: Filesystem uses "lzma" compression. This is not supported
SQUASHFS error: squashfs_read_data failed to read block 0x6081
SQUASHFS error: Unable to read metadata cache entry [6081]
SQUASHFS error: Unable to read inode 0x6000011a
---
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