From: syzbot <syzbot+0468b73bdbb243217224@syzkaller.appspotmail.com>
To: kyungmin.park@samsung.com, linux-kernel@vger.kernel.org,
linux-media@vger.kernel.org, m.szyprowski@samsung.com,
mchehab@kernel.org, pawel@osciak.com,
syzkaller-bugs@googlegroups.com
Subject: KASAN: null-ptr-deref Read in refcount_sub_and_test_checked (2)
Date: Tue, 13 Nov 2018 23:18:06 -0800 [thread overview]
Message-ID: <00000000000057e614057a9abcd3@google.com> (raw)
Hello,
syzbot found the following crash on:
HEAD commit: ccda4af0f4b9 Linux 4.20-rc2
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16f9cb0b400000
kernel config: https://syzkaller.appspot.com/x/.config?x=4a0a89f12ca9b0f5
dashboard link: https://syzkaller.appspot.com/bug?extid=0468b73bdbb243217224
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16d20893400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=118f5a2b400000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+0468b73bdbb243217224@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: null-ptr-deref in atomic_read
include/asm-generic/atomic-instrumented.h:21 [inline]
BUG: KASAN: null-ptr-deref in refcount_sub_and_test_checked+0x9d/0x310
lib/refcount.c:179
Read of size 4 at addr 0000000000000020 by task syz-executor487/6051
CPU: 0 PID: 6051 Comm: syz-executor487 Not tainted 4.20.0-rc2+ #333
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+0x244/0x39d lib/dump_stack.c:113
kasan_report_error mm/kasan/report.c:352 [inline]
kasan_report.cold.8+0x6d/0x309 mm/kasan/report.c:412
check_memory_region_inline mm/kasan/kasan.c:260 [inline]
check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272
atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
refcount_sub_and_test_checked+0x9d/0x310 lib/refcount.c:179
refcount_dec_and_test_checked+0x1a/0x20 lib/refcount.c:212
vb2_vmalloc_put+0x19/0x80
drivers/media/common/videobuf2/videobuf2-vmalloc.c:68
__vb2_buf_mem_free+0x112/0x210
drivers/media/common/videobuf2/videobuf2-core.c:242
__vb2_free_mem drivers/media/common/videobuf2/videobuf2-core.c:413 [inline]
__vb2_queue_free+0x830/0xa30
drivers/media/common/videobuf2/videobuf2-core.c:458
vb2_core_queue_release+0x62/0x80
drivers/media/common/videobuf2/videobuf2-core.c:2231
vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:837
[inline]
_vb2_fop_release+0x1d2/0x2b0
drivers/media/common/videobuf2/videobuf2-v4l2.c:1010
vb2_fop_release+0x77/0xc0
drivers/media/common/videobuf2/videobuf2-v4l2.c:1024
vivid_fop_release+0x18e/0x440 drivers/media/platform/vivid/vivid-core.c:474
v4l2_release+0x224/0x3a0 drivers/media/v4l2-core/v4l2-dev.c:456
__fput+0x385/0xa30 fs/file_table.c:278
____fput+0x15/0x20 fs/file_table.c:309
task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0x1ad6/0x26d0 kernel/exit.c:867
do_group_exit+0x177/0x440 kernel/exit.c:970
__do_sys_exit_group kernel/exit.c:981 [inline]
__se_sys_exit_group kernel/exit.c:979 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:979
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x442c78
Code: Bad RIP value.
RSP: 002b:00007fff4ac5a278 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442c78
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00000000004c2848 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d4180 R14: 0000000000000000 R15: 0000000000000000
==================================================================
---
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#bug-status-tracking for how to communicate with
syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches
next reply other threads:[~2018-11-14 17:20 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-14 7:18 syzbot [this message]
2019-03-21 17:39 ` KASAN: null-ptr-deref Read in refcount_sub_and_test_checked (2) syzbot
2019-12-07 1:30 ` 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=00000000000057e614057a9abcd3@google.com \
--to=syzbot+0468b73bdbb243217224@syzkaller.appspotmail.com \
--cc=kyungmin.park@samsung.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=m.szyprowski@samsung.com \
--cc=mchehab@kernel.org \
--cc=pawel@osciak.com \
--cc=syzkaller-bugs@googlegroups.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 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.