usercopy: kernel memory overwrite attempt detected to 00000000c1b1b006 (kmalloc-1024) (968 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: 26847 Comm: syz-executor6 Not tainted 4.15.0-rc5+ #170 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:ffff8801c1cb7a30 EFLAGS: 00010286 RAX: 0000000000000061 RBX: ffffffff85529380 RCX: 0000000000000000 RDX: 0000000000000061 RSI: ffffc90001960000 RDI: ffffed0038396f3a RBP: ffff8801c1cb7b20 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000f2009787 R11: 0000000000000000 R12: ffffffff85529340 R13: ffff8801be820e10 R14: 00000000000003c8 R15: ffffea0006fa0800 FS: 00007fd57624e700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560c3a819aa8 CR3: 00000001d01b6006 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] ___sys_sendmsg+0x59c/0x8b0 net/socket.c:1995 __sys_sendmsg+0xe5/0x210 net/socket.c:2052 SYSC_sendmsg net/socket.c:2063 [inline] SyS_sendmsg+0x2d/0x50 net/socket.c:2059 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452ac9 RSP: 002b:00007fd57624dc58 EFLAGS: 00000212 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fd57624e700 RCX: 0000000000452ac9 RDX: 0000000000000880 RSI: 0000000020989000 RDI: 0000000000000015 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000 R13: 0000000000a2f7ef R14: 00007fd57624e9c0 R15: 0000000000000000 Code: 48 0f 44 da e8 00 a0 c1 ff 48 8b 85 28 ff ff ff 4d 89 f1 4c 89 e9 4c 89 e2 48 89 de 48 c7 c7 40 94 52 85 49 89 c0 e8 c6 59 ab ff <0f> 0b 48 c7 c0 00 92 52 85 eb 96 48 c7 c0 40 92 52 85 eb 8d 48 RIP: report_usercopy mm/usercopy.c:64 [inline] RSP: ffff8801c1cb7a30 RIP: __check_object_size+0x3a2/0x4f0 mm/usercopy.c:264 RSP: ffff8801c1cb7a30 ---[ end trace ef5242fda886dec4 ]--- Kernel panic - not syncing: Fatal exception Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..