Messages in this thread | | | Date | Wed, 08 Jan 2020 00:54:07 -0800 | Subject | KASAN: null-ptr-deref Write in video_usercopy | From | syzbot <> |
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Hello,
syzbot found the following crash on:
HEAD commit: 26467385 Add linux-next specific files for 20200107 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=14160915e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=2265a716722be976 dashboard link: https://syzkaller.appspot.com/bug?extid=9240c422be249a8422bd compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15d162aee00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16b9c469e00000
The bug was bisected to:
commit c8ef1a6076bfb986052ff8fd8f5eb3b3a3f1048e Author: Arnd Bergmann <arnd@arndb.de> Date: Mon Dec 16 14:15:02 2019 +0000
media: v4l2-core: split out data copy from video_usercopy
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13442bc1e00000 final crash: https://syzkaller.appspot.com/x/report.txt?x=10c42bc1e00000 console output: https://syzkaller.appspot.com/x/log.txt?x=17442bc1e00000
IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+9240c422be249a8422bd@syzkaller.appspotmail.com Fixes: c8ef1a6076bf ("media: v4l2-core: split out data copy from video_usercopy")
================================================================== BUG: KASAN: null-ptr-deref in memset include/linux/string.h:411 [inline] BUG: KASAN: null-ptr-deref in video_get_user+0x67f/0x890 drivers/media/v4l2-core/v4l2-ioctl.c:3053 Write of size 512 at addr 0000000000000000 by task syz-executor806/9573
CPU: 0 PID: 9573 Comm: syz-executor806 Not tainted 5.5.0-rc5-next-20200107-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+0x197/0x210 lib/dump_stack.c:118 __kasan_report.cold+0x5/0x32 mm/kasan/report.c:510 kasan_report+0x12/0x20 mm/kasan/common.c:641 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192 memset+0x24/0x40 mm/kasan/common.c:108 memset include/linux/string.h:411 [inline] video_get_user+0x67f/0x890 drivers/media/v4l2-core/v4l2-ioctl.c:3053 video_usercopy+0x21f/0x10b0 drivers/media/v4l2-core/v4l2-ioctl.c:3210 video_ioctl2+0x2d/0x35 drivers/media/v4l2-core/v4l2-ioctl.c:3274 v4l2_ioctl+0x1ac/0x230 drivers/media/v4l2-core/v4l2-dev.c:360 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x123/0x180 fs/ioctl.c:747 __do_sys_ioctl fs/ioctl.c:756 [inline] __se_sys_ioctl fs/ioctl.c:754 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x440189 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffffba225e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440189 RDX: 0000000000000000 RSI: 0000001002008914 RDI: 0000000000000003 RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000401a10 R13: 0000000000401aa0 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#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches
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