From: syzbot <syzbot+39b64425f91b5aab714d@syzkaller.appspotmail.com>
To: andriin@fb.com, ast@kernel.org, bpf@vger.kernel.org,
daniel@iogearbox.net, john.fastabend@gmail.com, kafai@fb.com,
kpsingh@chromium.org, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, songliubraving@fb.com,
syzkaller-bugs@googlegroups.com, yhs@fb.com
Subject: KASAN: use-after-free Write in bpf_link_put
Date: Thu, 30 Apr 2020 02:39:13 -0700 [thread overview]
Message-ID: <0000000000006780dc05a47ed632@google.com> (raw)
Hello,
syzbot found the following crash on:
HEAD commit: 449e14bf bpf: Fix unused variable warning
git tree: bpf-next
console output: https://syzkaller.appspot.com/x/log.txt?x=109eb5f8100000
kernel config: https://syzkaller.appspot.com/x/.config?x=16d87c420507d444
dashboard link: https://syzkaller.appspot.com/bug?extid=39b64425f91b5aab714d
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+39b64425f91b5aab714d@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in atomic64_dec_and_test include/asm-generic/atomic-instrumented.h:1557 [inline]
BUG: KASAN: use-after-free in bpf_link_put+0x19/0x1b0 kernel/bpf/syscall.c:2255
Write of size 8 at addr ffff8880a7248800 by task syz-executor.0/28011
CPU: 0 PID: 28011 Comm: syz-executor.0 Not tainted 5.7.0-rc2-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+0x188/0x20d lib/dump_stack.c:118
print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:382
__kasan_report.cold+0x35/0x4d mm/kasan/report.c:511
kasan_report+0x33/0x50 mm/kasan/common.c:625
check_memory_region_inline mm/kasan/generic.c:187 [inline]
check_memory_region+0x141/0x190 mm/kasan/generic.c:193
atomic64_dec_and_test include/asm-generic/atomic-instrumented.h:1557 [inline]
bpf_link_put+0x19/0x1b0 kernel/bpf/syscall.c:2255
bpf_link_release+0x33/0x40 kernel/bpf/syscall.c:2270
__fput+0x33e/0x880 fs/file_table.c:280
task_work_run+0xf4/0x1b0 kernel/task_work.c:123
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165
prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305
entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x7fc891a66469
Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 8b 0d ff 49 2b 00 f7 d8 64 89 01 48
RSP: 002b:00007fc892156db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: fffffffffffffff4 RBX: 000000000042c4e0 RCX: 00007fc891a66469
RDX: 0000000000000010 RSI: 0000000020000040 RDI: 000000000000001c
RBP: 00000000006abf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005
R13: 000000000000004f R14: 0000000000415473 R15: 00007fc8921575c0
Allocated by task 28011:
save_stack+0x1b/0x40 mm/kasan/common.c:49
set_track mm/kasan/common.c:57 [inline]
__kasan_kmalloc mm/kasan/common.c:495 [inline]
__kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468
kmem_cache_alloc_trace+0x153/0x7d0 mm/slab.c:3551
kmalloc include/linux/slab.h:555 [inline]
kzalloc include/linux/slab.h:669 [inline]
cgroup_bpf_link_attach+0x13d/0x5b0 kernel/bpf/cgroup.c:894
link_create kernel/bpf/syscall.c:3765 [inline]
__do_sys_bpf+0x238c/0x46d0 kernel/bpf/syscall.c:3987
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
entry_SYSCALL_64_after_hwframe+0x49/0xb3
Freed by task 28011:
save_stack+0x1b/0x40 mm/kasan/common.c:49
set_track mm/kasan/common.c:57 [inline]
kasan_set_free_info mm/kasan/common.c:317 [inline]
__kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456
__cache_free mm/slab.c:3426 [inline]
kfree+0x109/0x2b0 mm/slab.c:3757
cgroup_bpf_link_attach+0x2bc/0x5b0 kernel/bpf/cgroup.c:906
link_create kernel/bpf/syscall.c:3765 [inline]
__do_sys_bpf+0x238c/0x46d0 kernel/bpf/syscall.c:3987
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
entry_SYSCALL_64_after_hwframe+0x49/0xb3
The buggy address belongs to the object at ffff8880a7248800
which belongs to the cache kmalloc-128 of size 128
The buggy address is located 0 bytes inside of
128-byte region [ffff8880a7248800, ffff8880a7248880)
The buggy address belongs to the page:
page:ffffea00029c9200 refcount:1 mapcount:0 mapping:00000000a3d4ec31 index:0xffff8880a7248700
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00024ceac8 ffffea000251d3c8 ffff8880aa000700
raw: ffff8880a7248700 ffff8880a7248000 000000010000000f 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8880a7248700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880a7248780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a7248800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880a7248880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880a7248900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
---
This bug 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 bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
next reply other threads:[~2020-04-30 9:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-30 9:39 syzbot [this message]
2020-04-30 14:33 ` KASAN: use-after-free Write in bpf_link_put Daniel Borkmann
2020-04-30 18:16 ` Andrii Nakryiko
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=0000000000006780dc05a47ed632@google.com \
--to=syzbot+39b64425f91b5aab714d@syzkaller.appspotmail.com \
--cc=andriin@fb.com \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=john.fastabend@gmail.com \
--cc=kafai@fb.com \
--cc=kpsingh@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=songliubraving@fb.com \
--cc=syzkaller-bugs@googlegroups.com \
--cc=yhs@fb.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox