usercopy: kernel memory overwrite attempt detected to 000000005d4a80b1 (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: 1 PID: 27648 Comm: syz-executor7 Not tainted 4.15.0-rc4+ #164 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:ffff8801be47f920 EFLAGS: 00010286 RAX: 0000000000000061 RBX: ffffffff85329080 RCX: 0000000000000000 RDX: 0000000000000061 RSI: ffffc90001b6c000 RDI: ffffed0037c8ff18 RBP: ffff8801be47fa10 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000491d6055 R11: 0000000000000000 R12: ffffffff85329040 R13: ffff8801c9e68510 R14: 00000000000003c8 R15: ffffea0007279a00 FS: 00007f432227a700(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000071c000 CR3: 00000001d25ad001 CR4: 00000000001606e0 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_sendmmsg+0x1ee/0x620 net/socket.c:2108 SYSC_sendmmsg net/socket.c:2139 [inline] SyS_sendmmsg+0x35/0x60 net/socket.c:2134 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452ac9 RSP: 002b:00007f4322279c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 000000000071bf58 RCX: 0000000000452ac9 RDX: 0000000000000001 RSI: 00000000203ef000 RDI: 0000000000000013 RBP: 000000000000053c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f4e40 R13: 00000000ffffffff R14: 00007f432227a6d4 R15: 0000000000000006 Code: 48 0f 44 da e8 d0 bf 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 91 32 85 49 89 c0 e8 b6 7b ab ff <0f> 0b 48 c7 c0 00 8f 32 85 eb 96 48 c7 c0 40 8f 32 85 eb 8d 48 RIP: report_usercopy mm/usercopy.c:64 [inline] RSP: ffff8801be47f920 RIP: __check_object_size+0x3a2/0x4f0 mm/usercopy.c:264 RSP: ffff8801be47f920 ---[ end trace 545ef7382b71df04 ]--- Kernel panic - not syncing: Fatal exception Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..