usercopy: kernel memory overwrite attempt detected to 0000000012b9c99b (kmalloc-1024) (1008 bytes) ------------[ cut here ]------------ kernel BUG at mm/usercopy.c:72! invalid opcode: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 30652 Comm: syz-executor3 Not tainted 4.15.0-rc5+ #177 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:report_usercopy mm/usercopy.c:64 [inline] RIP: 0010:__check_object_size+0x3a2/0x4f0 mm/usercopy.c:264 RSP: 0018:ffff8801c44bf838 EFLAGS: 00010282 RAX: 0000000000000062 RBX: ffffffff8592bb60 RCX: 0000000000000000 RDX: 0000000000000062 RSI: ffffc90003c29000 RDI: ffffed0038897efb RBP: ffff8801c44bf928 R08: 0000000000000000 R09: 0000000000000000 R10: 000000001b816822 R11: 0000000000000000 R12: ffffffff8592bb20 R13: ffff8801c2152990 R14: 00000000000003f0 R15: ffffea0007085480 FS: 00007f8c564b7700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000071c000 CR3: 00000001bd344003 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: check_object_size include/linux/thread_info.h:112 [inline] check_copy_size include/linux/thread_info.h:143 [inline] copy_from_user include/linux/uaccess.h:146 [inline] rw_copy_check_uvector+0x73/0x280 fs/read_write.c:760 import_iovec+0xc8/0x430 lib/iov_iter.c:1398 copy_msghdr_from_user+0x39b/0x590 net/socket.c:1937 ___sys_recvmsg+0x15a/0x640 net/socket.c:2165 __sys_recvmsg+0xe2/0x210 net/socket.c:2222 SYSC_recvmsg net/socket.c:2234 [inline] SyS_recvmsg+0x2d/0x50 net/socket.c:2229 entry_SYSCALL_64_fastpath+0x23/0x9a RIP: 0033:0x452ac9 RSP: 002b:00007f8c564b6c58 EFLAGS: 00000212 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9 RDX: 0000000000000002 RSI: 0000000020f66000 RDI: 0000000000000013 RBP: 00000000000003a3 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f37e8 R13: 00000000ffffffff R14: 00007f8c564b76d4 R15: 0000000000000000 Code: 48 0f 44 da e8 70 5b c0 ff 48 8b 85 28 ff ff ff 4d 89 f1 4c 89 e9 4c 89 e2 48 89 de 48 c7 c7 20 bc 92 85 49 89 c0 e8 e6 10 aa ff <0f> 0b 48 c7 c0 e0 b9 92 85 eb 96 48 c7 c0 20 ba 92 85 eb 8d 48 RIP: report_usercopy mm/usercopy.c:64 [inline] RSP: ffff8801c44bf838 RIP: __check_object_size+0x3a2/0x4f0 mm/usercopy.c:264 RSP: ffff8801c44bf838 ---[ end trace f40df7de557d01f4 ]--- Kernel panic - not syncing: Fatal exception Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..