From: syzbot <syzbot+8bee3285b9e190f1509e@syzkaller.appspotmail.com>
To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-unionfs@vger.kernel.org, miklos@szeredi.hu,
mszeredi@redhat.com, syzkaller-bugs@googlegroups.com,
tj@kernel.org
Subject: [syzbot] KASAN: use-after-free Read in __kernfs_remove
Date: Thu, 25 Aug 2022 11:25:34 -0700 [thread overview]
Message-ID: <000000000000646c9605e714ec6e@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 68a00424bf69 Add linux-next specific files for 20220824
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=10cedc45080000
kernel config: https://syzkaller.appspot.com/x/.config?x=591008a24ae652d0
dashboard link: https://syzkaller.appspot.com/bug?extid=8bee3285b9e190f1509e
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=123a6fb5080000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15381113080000
The issue was bisected to:
commit b10b85fe5149ee8b39fbbf86095b303632dde2cd
Author: Miklos Szeredi <mszeredi@redhat.com>
Date: Wed Jul 27 14:31:30 2022 +0000
ovl: warn if trusted xattr creation fails
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=126b3c65080000
final oops: https://syzkaller.appspot.com/x/report.txt?x=116b3c65080000
console output: https://syzkaller.appspot.com/x/log.txt?x=166b3c65080000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8bee3285b9e190f1509e@syzkaller.appspotmail.com
Fixes: b10b85fe5149 ("ovl: warn if trusted xattr creation fails")
==================================================================
BUG: KASAN: use-after-free in kernfs_type include/linux/kernfs.h:335 [inline]
BUG: KASAN: use-after-free in kernfs_leftmost_descendant fs/kernfs/dir.c:1261 [inline]
BUG: KASAN: use-after-free in __kernfs_remove+0xa09/0xb50 fs/kernfs/dir.c:1369
Read of size 2 at addr ffff8880175239a8 by task syz-executor325/4044
CPU: 1 PID: 4044 Comm: syz-executor325 Not tainted 6.0.0-rc2-next-20220824-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:317 [inline]
print_report.cold+0x2ba/0x719 mm/kasan/report.c:433
kasan_report+0xb1/0x1e0 mm/kasan/report.c:495
kernfs_type include/linux/kernfs.h:335 [inline]
kernfs_leftmost_descendant fs/kernfs/dir.c:1261 [inline]
__kernfs_remove+0xa09/0xb50 fs/kernfs/dir.c:1369
kernfs_remove_by_name_ns+0xa8/0x110 fs/kernfs/dir.c:1589
sysfs_slab_add+0x13e/0x1e0 mm/slub.c:5756
__kmem_cache_create+0x509/0x690 mm/slub.c:4745
create_cache mm/slab_common.c:229 [inline]
kmem_cache_create_usercopy+0x1f9/0x300 mm/slab_common.c:335
p9_client_create+0xca5/0x1070 net/9p/client.c:993
v9fs_session_init+0x1e2/0x1810 fs/9p/v9fs.c:408
v9fs_mount+0xba/0xc90 fs/9p/vfs_super.c:126
legacy_get_tree+0x105/0x220 fs/fs_context.c:610
vfs_get_tree+0x89/0x2f0 fs/super.c:1530
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x1326/0x1e20 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
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+0x63/0xcd
RIP: 0033:0x7f9adb816389
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 14 00 00 90 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff4b66cf98 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fff4b66cfd0 RCX: 00007f9adb816389
RDX: 0000000020000280 RSI: 00000000200002c0 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000020000140 R09: 000000000000c837
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000f4240
R13: 000000000000c837 R14: 00007fff4b66cfbc R15: 00007fff4b66cfc0
</TASK>
Allocated by task 4039:
kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:45 [inline]
set_alloc_info mm/kasan/common.c:437 [inline]
__kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:470
kasan_slab_alloc include/linux/kasan.h:224 [inline]
slab_post_alloc_hook mm/slab.h:737 [inline]
slab_alloc_node mm/slub.c:3229 [inline]
slab_alloc mm/slub.c:3237 [inline]
__kmem_cache_alloc_lru mm/slub.c:3244 [inline]
kmem_cache_alloc+0x2b7/0x3d0 mm/slub.c:3253
kmem_cache_zalloc include/linux/slab.h:685 [inline]
__kernfs_new_node+0xd4/0x8b0 fs/kernfs/dir.c:593
kernfs_new_node fs/kernfs/dir.c:655 [inline]
kernfs_create_dir_ns+0x9c/0x220 fs/kernfs/dir.c:1010
sysfs_create_dir_ns+0x127/0x290 fs/sysfs/dir.c:59
create_dir lib/kobject.c:63 [inline]
kobject_add_internal+0x2c9/0x8f0 lib/kobject.c:223
kobject_add_varg lib/kobject.c:358 [inline]
kobject_init_and_add+0x101/0x160 lib/kobject.c:441
sysfs_slab_add+0x161/0x1e0 mm/slub.c:5767
__kmem_cache_create+0x509/0x690 mm/slub.c:4745
create_cache mm/slab_common.c:229 [inline]
kmem_cache_create_usercopy+0x1f9/0x300 mm/slab_common.c:335
p9_client_create+0xca5/0x1070 net/9p/client.c:993
v9fs_session_init+0x1e2/0x1810 fs/9p/v9fs.c:408
v9fs_mount+0xba/0xc90 fs/9p/vfs_super.c:126
legacy_get_tree+0x105/0x220 fs/fs_context.c:610
vfs_get_tree+0x89/0x2f0 fs/super.c:1530
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x1326/0x1e20 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
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+0x63/0xcd
Freed by task 4044:
kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
kasan_set_track+0x21/0x30 mm/kasan/common.c:45
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
____kasan_slab_free mm/kasan/common.c:367 [inline]
____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:329
kasan_slab_free include/linux/kasan.h:200 [inline]
slab_free_hook mm/slub.c:1740 [inline]
slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1766
slab_free mm/slub.c:3497 [inline]
kmem_cache_free+0xe7/0x5b0 mm/slub.c:3519
kernfs_put.part.0+0x2c4/0x540 fs/kernfs/dir.c:547
kernfs_put+0x42/0x50 fs/kernfs/dir.c:521
__kernfs_remove+0x7a6/0xb50 fs/kernfs/dir.c:1407
kernfs_remove_by_name_ns+0xa8/0x110 fs/kernfs/dir.c:1589
sysfs_slab_add+0x13e/0x1e0 mm/slub.c:5756
__kmem_cache_create+0x509/0x690 mm/slub.c:4745
create_cache mm/slab_common.c:229 [inline]
kmem_cache_create_usercopy+0x1f9/0x300 mm/slab_common.c:335
p9_client_create+0xca5/0x1070 net/9p/client.c:993
v9fs_session_init+0x1e2/0x1810 fs/9p/v9fs.c:408
v9fs_mount+0xba/0xc90 fs/9p/vfs_super.c:126
legacy_get_tree+0x105/0x220 fs/fs_context.c:610
vfs_get_tree+0x89/0x2f0 fs/super.c:1530
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x1326/0x1e20 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
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+0x63/0xcd
The buggy address belongs to the object at ffff888017523910
which belongs to the cache kernfs_node_cache of size 168
The buggy address is located 152 bytes inside of
168-byte region [ffff888017523910, ffff8880175239b8)
The buggy address belongs to the physical page:
page:ffffea00005d48c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888017523570 pfn:0x17523
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea00005d4c80 dead000000000006 ffff8880119d4c80
raw: ffff888017523570 000000008011000b 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, tgid 1 (swapper/0), ts 2122740088, free_ts 0
prep_new_page mm/page_alloc.c:2532 [inline]
get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283
__alloc_pages+0x1c7/0x510 mm/page_alloc.c:5507
alloc_page_interleave+0x1e/0x200 mm/mempolicy.c:2113
alloc_pages+0x22f/0x270 mm/mempolicy.c:2275
alloc_slab_page mm/slub.c:1810 [inline]
allocate_slab+0x27e/0x3d0 mm/slub.c:1955
new_slab mm/slub.c:2015 [inline]
___slab_alloc+0xa3e/0x11d0 mm/slub.c:3017
__slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3104
slab_alloc_node mm/slub.c:3195 [inline]
slab_alloc mm/slub.c:3237 [inline]
__kmem_cache_alloc_lru mm/slub.c:3244 [inline]
kmem_cache_alloc+0x31c/0x3d0 mm/slub.c:3253
kmem_cache_zalloc include/linux/slab.h:685 [inline]
__kernfs_new_node+0xd4/0x8b0 fs/kernfs/dir.c:593
kernfs_new_node fs/kernfs/dir.c:655 [inline]
kernfs_create_dir_ns+0x9c/0x220 fs/kernfs/dir.c:1010
internal_create_group+0x787/0xb10 fs/sysfs/group.c:136
kernel_add_sysfs_param kernel/params.c:814 [inline]
param_sysfs_builtin kernel/params.c:851 [inline]
param_sysfs_init+0x342/0x43b kernel/params.c:970
do_one_initcall+0xfe/0x650 init/main.c:1301
do_initcall_level init/main.c:1376 [inline]
do_initcalls init/main.c:1392 [inline]
do_basic_setup init/main.c:1411 [inline]
kernel_init_freeable+0x6b1/0x73a init/main.c:1630
kernel_init+0x1a/0x1d0 init/main.c:1519
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
page_owner free stack trace missing
Memory state around the buggy address:
ffff888017523880: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc
ffff888017523900: fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888017523980: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fa
^
ffff888017523a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888017523a80: fb fb fb fb fc fc fc fc fc fc fc fc fa 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.
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
next reply other threads:[~2022-08-25 18:25 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-25 18:25 syzbot [this message]
2022-09-25 12:29 ` [PATCH] kernfs: fix UAF race condition in __kernfs_remove() Tetsuo Handa
2022-09-25 13:13 ` Greg Kroah-Hartman
2022-09-25 13:20 ` Tetsuo Handa
2022-09-25 13:40 ` Greg Kroah-Hartman
2022-09-25 13:52 ` Tetsuo Handa
2022-09-25 16:52 ` Christian A. Ehrhardt
[not found] <20220826121322.2495-1-hdanton@sina.com>
2022-08-26 13:59 ` [syzbot] KASAN: use-after-free Read in __kernfs_remove syzbot
[not found] <20220827002401.2552-1-hdanton@sina.com>
2022-08-27 0:43 ` 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=000000000000646c9605e714ec6e@google.com \
--to=syzbot+8bee3285b9e190f1509e@syzkaller.appspotmail.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-unionfs@vger.kernel.org \
--cc=miklos@szeredi.hu \
--cc=mszeredi@redhat.com \
--cc=syzkaller-bugs@googlegroups.com \
--cc=tj@kernel.org \
/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.