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@xxxxxxxxxxxxxxxxxxxxxxxxx ===================================================== 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 ===================================================== --- 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@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
