From: syzbot <syzbot+79d751604cb6f29fbf59@syzkaller.appspotmail.com>
To: arnd@arndb.de, bnvandana@gmail.com, glider@google.com,
hverkuil-cisco@xs4all.nl, laurent.pinchart@ideasonboard.com,
linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
mchehab@kernel.org, niklas.soderlund+renesas@ragnatech.se,
sakari.ailus@linux.intel.com, syzkaller-bugs@googlegroups.com
Subject: KMSAN: uninit-value in video_usercopy
Date: Tue, 21 Jul 2020 22:53:19 -0700 [thread overview]
Message-ID: <000000000000588d8b05ab015bed@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 14525656 compiler.h: reinstate missing KMSAN_INIT
git tree: https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=15be8380900000
kernel config: https://syzkaller.appspot.com/x/.config?x=c534a9fad6323722
dashboard link: https://syzkaller.appspot.com/bug?extid=79d751604cb6f29fbf59
compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17eb93d0900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=116da33b100000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+79d751604cb6f29fbf59@syzkaller.appspotmail.com
=====================================================
BUG: KMSAN: uninit-value in kmsan_check_memory+0xd/0x10 mm/kmsan/kmsan_hooks.c:428
CPU: 0 PID: 8471 Comm: syz-executor794 Not tainted 5.8.0-rc5-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+0x1df/0x240 lib/dump_stack.c:118
kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121
kmsan_internal_check_memory+0x238/0x3d0 mm/kmsan/kmsan.c:423
kmsan_check_memory+0xd/0x10 mm/kmsan/kmsan_hooks.c:428
instrument_copy_to_user include/linux/instrumented.h:91 [inline]
_copy_to_user+0x100/0x1d0 lib/usercopy.c:30
copy_to_user include/linux/uaccess.h:161 [inline]
video_put_user drivers/media/v4l2-core/v4l2-ioctl.c:3226 [inline]
video_usercopy+0x248a/0x2c00 drivers/media/v4l2-core/v4l2-ioctl.c:3325
video_ioctl2+0x9f/0xb0 drivers/media/v4l2-core/v4l2-ioctl.c:3335
v4l2_ioctl+0x23f/0x270 drivers/media/v4l2-core/v4l2-dev.c:360
vfs_ioctl fs/ioctl.c:48 [inline]
ksys_ioctl fs/ioctl.c:753 [inline]
__do_sys_ioctl fs/ioctl.c:762 [inline]
__se_sys_ioctl+0x2e9/0x410 fs/ioctl.c:760
__x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:760
do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x444009
Code: Bad RIP value.
RSP: 002b:00007ffd83706aa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000444009
RDX: 0000000020000100 RSI: 00000000c0505611 RDI: 0000000000000003
RBP: 00000000006ce018 R08: 00000000004002e0 R09: 00000000004002e0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401c90
R13: 0000000000401d20 R14: 0000000000000000 R15: 0000000000000000
Local variable ----vb32.i@video_usercopy created at:
video_put_user drivers/media/v4l2-core/v4l2-ioctl.c:3210 [inline]
video_usercopy+0x20bd/0x2c00 drivers/media/v4l2-core/v4l2-ioctl.c:3325
video_put_user drivers/media/v4l2-core/v4l2-ioctl.c:3210 [inline]
video_usercopy+0x20bd/0x2c00 drivers/media/v4l2-core/v4l2-ioctl.c:3325
Bytes 52-55 of 80 are uninitialized
Memory access of size 80 starts at ffffa41d80dcfce0
=====================================================
---
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reply other threads:[~2020-07-22 5:53 UTC|newest]
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