Hello,
syzbot found the following issue on:
HEAD commit: d7a03a44 Add linux-next specific files for 20201223
git tree: linux-next
console output:
https://syzkaller.appspot.com/x/log.txt?x=16308e93500000
kernel config:
https://syzkaller.appspot.com/x/.config?x=cef3a83fd396e47
dashboard link:
https://syzkaller.appspot.com/bug?extid=5c77c3285684d0ad9886
compiler: gcc (GCC) 10.1.0-syz 20200507
CC: [
jmo...@namei.org linux-...@vger.kernel.org linux-secu...@vger.kernel.org penguin...@I-love.SAKURA.ne.jp se...@hallyn.com take...@nttdata.co.jp]
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+5c77c3...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in tomoyo_path_matches_pattern+0x278/0x280 security/tomoyo/util.c:941
Read of size 8 at addr ffff888012a6e218 by task syz-executor.4/14176
CPU: 1 PID: 14176 Comm: syz-executor.4 Not tainted 5.10.0-next-20201223-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x107/0x163 lib/dump_stack.c:120
print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:230
__kasan_report mm/kasan/report.c:396 [inline]
kasan_report.cold+0x79/0xd5 mm/kasan/report.c:413
tomoyo_path_matches_pattern+0x278/0x280 security/tomoyo/util.c:941
tomoyo_compare_name_union security/tomoyo/file.c:87 [inline]
tomoyo_compare_name_union security/tomoyo/file.c:82 [inline]
tomoyo_check_path_acl security/tomoyo/file.c:260 [inline]
tomoyo_check_path_acl+0x164/0x1f0 security/tomoyo/file.c:252
tomoyo_check_acl+0x13c/0x450 security/tomoyo/domain.c:175
tomoyo_path_permission security/tomoyo/file.c:586 [inline]
tomoyo_path_permission+0x1ff/0x3a0 security/tomoyo/file.c:573
tomoyo_path_perm+0x2f0/0x400 security/tomoyo/file.c:838
security_inode_getattr+0xcf/0x140 security/security.c:1280
vfs_getattr fs/stat.c:121 [inline]
vfs_fstat+0x43/0xb0 fs/stat.c:146
__do_sys_newfstat+0x81/0x100 fs/stat.c:386
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d604
Code: c0 d4 ff ff ff 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 83 ff 01 89 f0 77 31 48 63 f8 48 89 d6 b8 05 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 04 f3 c3 66 90 48 c7 c2 d4 ff ff ff f7 d8 64
RSP: 002b:00007ffc9b6418b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000005
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045d604
RDX: 00007ffc9b6418c0 RSI: 00007ffc9b6418c0 RDI: 0000000000000003
RBP: 000000000009dc31 R08: 0000000000000000 R09: 0000000001ad9940
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc9b642ac0
R13: 0000000000000002 R14: 0000000000000000 R15: 000000000009db78
Allocated by task 11335:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:404 [inline]
____kasan_kmalloc mm/kasan/common.c:435 [inline]
____kasan_kmalloc.constprop.0+0xa0/0xd0 mm/kasan/common.c:407
kmalloc include/linux/slab.h:557 [inline]
kzalloc include/linux/slab.h:682 [inline]
tomoyo_get_name+0x234/0x480 security/tomoyo/memory.c:173
tomoyo_parse_name_union+0xbc/0x160 security/tomoyo/util.c:260
tomoyo_update_path_acl security/tomoyo/file.c:395 [inline]
tomoyo_write_file+0x4c0/0x7f0 security/tomoyo/file.c:1022
tomoyo_write_domain2+0x116/0x1d0 security/tomoyo/common.c:1152
tomoyo_add_entry security/tomoyo/common.c:2042 [inline]
tomoyo_supervisor+0xbc4/0xef0 security/tomoyo/common.c:2103
tomoyo_audit_path_log security/tomoyo/file.c:168 [inline]
tomoyo_path_permission security/tomoyo/file.c:587 [inline]
tomoyo_path_permission+0x270/0x3a0 security/tomoyo/file.c:573
tomoyo_path_perm+0x39e/0x400 security/tomoyo/file.c:838
tomoyo_path_symlink+0x94/0xe0 security/tomoyo/tomoyo.c:200
security_path_symlink+0xdf/0x150 security/security.c:1111
do_symlinkat+0x123/0x2c0 fs/namei.c:3987
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Freed by task 19145:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:355
____kasan_slab_free.part.0+0xe1/0x110 mm/kasan/common.c:365
kasan_slab_free include/linux/kasan.h:188 [inline]
slab_free_hook mm/slub.c:1548 [inline]
slab_free_freelist_hook+0x82/0x1d0 mm/slub.c:1586
slab_free mm/slub.c:3157 [inline]
kfree+0xe5/0x5c0 mm/slub.c:4156
bdev_free_inode+0x57/0x80 fs/block_dev.c:787
i_callback+0x3f/0x70 fs/inode.c:222
rcu_do_batch kernel/rcu/tree.c:2489 [inline]
rcu_core+0x5eb/0xf00 kernel/rcu/tree.c:2723
__do_softirq+0x2a5/0x9f7 kernel/softirq.c:343
The buggy address belongs to the object at ffff888012a6e200
which belongs to the cache kmalloc-128 of size 128
The buggy address is located 24 bytes inside of
128-byte region [ffff888012a6e200, ffff888012a6e280)
The buggy address belongs to the page:
page:00000000cfea1e35 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12a6e
flags: 0xfff00000000200(slab)
raw: 00fff00000000200 ffffea00009cf8c0 0000000300000003 ffff888010041640
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888012a6e100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888012a6e180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888012a6e200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888012a6e280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888012a6e300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
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