general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] CPU: 0 PID: 8763 Comm: syz-executor836 Not tainted 5.11.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mptcp_sendmsg_frag+0xa3f/0x1220 net/mptcp/protocol.c:1330 Code: 80 3c 02 00 0f 85 04 07 00 00 48 8b 04 24 48 8b 98 20 07 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 38 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e d6 04 00 00 48 8d 7d 10 44 8b RSP: 0018:ffffc90001dff7e8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000038 RBP: ffff8880120d9e10 R08: 0000000000000001 R09: ffff8880120d9e10 R10: ffffed100241b3c4 R11: 0000000000000000 R12: ffff88801bf51800 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000008000 FS: 00007f0f56768700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000084 CR3: 000000001b547000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mptcp_push_pending+0x2cc/0x650 net/mptcp/protocol.c:1477 mptcp_sendmsg+0x1ffb/0x2830 net/mptcp/protocol.c:1692 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:638 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 sock_write_iter+0x289/0x3c0 net/socket.c:999 call_write_iter include/linux/fs.h:1901 [inline] new_sync_write+0x426/0x650 fs/read_write.c:518 vfs_write+0x791/0xa30 fs/read_write.c:605 ksys_write+0x1ee/0x250 fs/read_write.c:658 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x4492d9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 15 00 00 90 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0f56768318 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000004cf4c8 RCX: 00000000004492d9 RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000004cf4c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cf4cc R13: 00007fff4b6baf0f R14: 00007f0f56768400 R15: 0000000000022000 Modules linked in: ---[ end trace a30ad1b3e9650ce6 ]--- RIP: 0010:mptcp_sendmsg_frag+0xa3f/0x1220 net/mptcp/protocol.c:1330 Code: 80 3c 02 00 0f 85 04 07 00 00 48 8b 04 24 48 8b 98 20 07 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 38 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e d6 04 00 00 48 8d 7d 10 44 8b RSP: 0018:ffffc90001dff7e8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000038 RBP: ffff8880120d9e10 R08: 0000000000000001 R09: ffff8880120d9e10 R10: ffffed100241b3c4 R11: 0000000000000000 R12: ffff88801bf51800 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000008000 FS: 00007f0f56768700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f97dbf78000 CR3: 000000001b547000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400