From: syzbot <syzbot+fb0d60a179096e8c2731@syzkaller.appspotmail.com>
To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk
Subject: [syzbot] KASAN: use-after-free Read in __d_alloc (2)
Date: Mon, 16 Aug 2021 01:27:24 -0700 [thread overview]
Message-ID: <0000000000007d148a05c9a8f898@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: b9011c7e671d Add linux-next specific files for 20210816
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17cc067e300000
kernel config: https://syzkaller.appspot.com/x/.config?x=a245d1aa4f055cc1
dashboard link: https://syzkaller.appspot.com/bug?extid=fb0d60a179096e8c2731
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
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+fb0d60a179096e8c2731@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in memcpy include/linux/fortify-string.h:191 [inline]
BUG: KASAN: use-after-free in __d_alloc+0x19a/0x950 fs/dcache.c:1775
Read of size 5 at addr ffff88807c499120 by task kdevtmpfs/22
CPU: 0 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-rc5-next-20210816-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:256
__kasan_report mm/kasan/report.c:442 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
memcpy+0x20/0x60 mm/kasan/shadow.c:65
memcpy include/linux/fortify-string.h:191 [inline]
__d_alloc+0x19a/0x950 fs/dcache.c:1775
d_alloc+0x4a/0x230 fs/dcache.c:1823
__lookup_hash+0xc8/0x180 fs/namei.c:1554
kern_path_locked+0x17e/0x320 fs/namei.c:2567
handle_remove+0xa2/0x5fe drivers/base/devtmpfs.c:312
handle drivers/base/devtmpfs.c:382 [inline]
devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline]
devtmpfsd+0x1b9/0x2a3 drivers/base/devtmpfs.c:437
kthread+0x3e5/0x4d0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Allocated by task 22:
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:434 [inline]
__kasan_slab_alloc+0x84/0xa0 mm/kasan/common.c:467
kasan_slab_alloc include/linux/kasan.h:254 [inline]
slab_post_alloc_hook mm/slab.h:519 [inline]
slab_alloc_node mm/slub.c:3173 [inline]
slab_alloc mm/slub.c:3181 [inline]
kmem_cache_alloc+0x20d/0x390 mm/slub.c:3186
getname_kernel+0x4e/0x370 fs/namei.c:226
kern_path_locked+0x71/0x320 fs/namei.c:2558
handle_remove+0xa2/0x5fe drivers/base/devtmpfs.c:312
handle drivers/base/devtmpfs.c:382 [inline]
devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline]
devtmpfsd+0x1b9/0x2a3 drivers/base/devtmpfs.c:437
kthread+0x3e5/0x4d0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Freed by task 22:
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:360
____kasan_slab_free mm/kasan/common.c:366 [inline]
____kasan_slab_free mm/kasan/common.c:328 [inline]
__kasan_slab_free+0xfb/0x130 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1681 [inline]
slab_free_freelist_hook+0x7e/0x190 mm/slub.c:1706
slab_free mm/slub.c:3450 [inline]
kmem_cache_free+0x8a/0x5a0 mm/slub.c:3466
putname.part.0+0xe1/0x120 fs/namei.c:270
putname include/linux/err.h:41 [inline]
filename_parentat fs/namei.c:2547 [inline]
kern_path_locked+0xc2/0x320 fs/namei.c:2558
handle_remove+0xa2/0x5fe drivers/base/devtmpfs.c:312
handle drivers/base/devtmpfs.c:382 [inline]
devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline]
devtmpfsd+0x1b9/0x2a3 drivers/base/devtmpfs.c:437
kthread+0x3e5/0x4d0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
The buggy address belongs to the object at ffff88807c499100
which belongs to the cache names_cache of size 4096
The buggy address is located 32 bytes inside of
4096-byte region [ffff88807c499100, ffff88807c49a100)
The buggy address belongs to the page:
page:ffffea0001f12600 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807c49e600 pfn:0x7c498
head:ffffea0001f12600 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888010dc53c0
raw: ffff88807c49e600 0000000080070005 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2981, ts 211981674424, free_ts 211786490796
prep_new_page mm/page_alloc.c:2424 [inline]
get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4151
__alloc_pages+0x1b2/0x500 mm/page_alloc.c:5373
alloc_pages+0x1a7/0x300 mm/mempolicy.c:2188
alloc_slab_page mm/slub.c:1744 [inline]
allocate_slab mm/slub.c:1881 [inline]
new_slab+0x319/0x490 mm/slub.c:1944
___slab_alloc+0x8b9/0xf50 mm/slub.c:2961
__slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3048
slab_alloc_node mm/slub.c:3139 [inline]
slab_alloc mm/slub.c:3181 [inline]
kmem_cache_alloc+0x369/0x390 mm/slub.c:3186
getname_flags.part.0+0x50/0x4f0 fs/namei.c:138
getname_flags+0x9a/0xe0 include/linux/audit.h:319
user_path_at_empty+0x2b/0x90 fs/namei.c:2801
user_path_at include/linux/namei.h:57 [inline]
do_faccessat+0x127/0x850 fs/open.c:425
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1338 [inline]
free_pcp_prepare+0x373/0x860 mm/page_alloc.c:1389
free_unref_page_prepare mm/page_alloc.c:3315 [inline]
free_unref_page+0x19/0x690 mm/page_alloc.c:3394
qlink_free mm/kasan/quarantine.c:146 [inline]
qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165
kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272
__kasan_slab_alloc+0x8e/0xa0 mm/kasan/common.c:444
kasan_slab_alloc include/linux/kasan.h:254 [inline]
slab_post_alloc_hook mm/slab.h:519 [inline]
slab_alloc_node mm/slub.c:3173 [inline]
slab_alloc mm/slub.c:3181 [inline]
__kmalloc+0x1eb/0x320 mm/slub.c:4354
kmalloc include/linux/slab.h:596 [inline]
tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822
security_inode_getattr+0xcf/0x140 security/security.c:1333
vfs_getattr fs/stat.c:157 [inline]
vfs_fstat+0x43/0xb0 fs/stat.c:182
__do_sys_newfstat+0x81/0x100 fs/stat.c:422
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Memory state around the buggy address:
ffff88807c499000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88807c499080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88807c499100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88807c499180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88807c499200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
---
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@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
next reply other threads:[~2021-08-16 8:27 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-16 8:27 syzbot [this message]
2021-08-17 1:14 ` [syzbot] KASAN: use-after-free Read in __d_alloc (2) syzbot
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=0000000000007d148a05c9a8f898@google.com \
--to=syzbot+fb0d60a179096e8c2731@syzkaller.appspotmail.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=syzkaller-bugs@googlegroups.com \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.