WARNING in warn_bad

WARNING in warn_bad_map
Status: fixed on 2020/07/20 08:03
Reported-by: syzbot+42a07faa5923cfaeb9c9@syzkaller.appspotmail.com
Fix commit: 9c29e3615274 mptcp: fix DSS map generation on fin retransmission
First crash: 458d, last: 458d

Sample crash report:

------------[ cut here ]------------
Bad mapping: ssn=2478501 map_seq=0 map_data_len=32748
WARNING: CPU: 0 PID: 20706 at net/mptcp/subflow.c:581 warn_bad_map.isra.0.part.0+0x7d/0xb0 net/mptcp/subflow.c:581
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 20706 Comm: syz-executor.2 Not tainted 5.7.0-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+0x188/0x20d lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x35 kernel/panic.c:582
 report_bug+0x27b/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:105 [inline]
 fixup_bug arch/x86/kernel/traps.c:100 [inline]
 do_error_trap+0x12b/0x220 arch/x86/kernel/traps.c:197
 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:216
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:warn_bad_map.isra.0.part.0+0x7d/0xb0 net/mptcp/subflow.c:581
Code: 48 c1 ea 03 0f b6 14 02 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1c 8b 13 44 89 e6 48 c7 c7 20 5c fe 88 e8 4b 2e 6b f9 <0f> 0b 48 83 c4 08 5b 5d 41 5c c3 48 89 df 89 4c 24 04 e8 7c 3f d9
RSP: 0018:ffffc90006f2f420 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff88809e4fe43c RCX: 0000000000000000
RDX: 0000000000040000 RSI: ffffffff815d5ba7 RDI: fffff52000de5e76
RBP: ffff88809e4fe444 R08: ffff8880850aa580 R09: 0000000000000001
R10: ffffffff8c347a27 R11: fffffbfff1868f44 R12: 000000000025d1a5
R13: ffff88809e4fe400 R14: ffff88809e4fe444 R15: ffff88809e4fe43c
 warn_bad_map net/mptcp/subflow.c:613 [inline]
 validate_mapping net/mptcp/subflow.c:613 [inline]
 get_mapping_status net/mptcp/subflow.c:728 [inline]
 subflow_check_data_avail net/mptcp/subflow.c:766 [inline]
 mptcp_subflow_data_available+0x145b/0x1aa0 net/mptcp/subflow.c:862
 subflow_data_ready+0x10b/0x170 net/mptcp/subflow.c:903
 tcp_data_ready+0xe8/0x230 net/ipv4/tcp_input.c:4776
 tcp_data_queue+0x1161/0x4760 net/ipv4/tcp_input.c:4842
 tcp_rcv_established+0x905/0x1d90 net/ipv4/tcp_input.c:5735
 tcp_v4_do_rcv+0x605/0x8b0 net/ipv4/tcp_ipv4.c:1629
 sk_backlog_rcv include/net/sock.h:996 [inline]
 __release_sock+0x134/0x3a0 net/core/sock.c:2548
 release_sock+0x54/0x1b0 net/core/sock.c:3064
 mptcp_sendmsg+0x11f9/0x17f0 net/mptcp/protocol.c:872
 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:814
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 sock_write_iter+0x288/0x3c0 net/socket.c:999
 call_write_iter include/linux/fs.h:1917 [inline]
 do_iter_readv_writev+0x51e/0x790 fs/read_write.c:694
 do_iter_write fs/read_write.c:999 [inline]
 do_iter_write+0x18b/0x600 fs/read_write.c:980
 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1072
 do_writev+0x27f/0x300 fs/read_write.c:1115
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca59
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5887229c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 000000000050e320 RCX: 000000000045ca59
RDX: 0000000000000001 RSI: 0000000020000200 RDI: 0000000000000004
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000d43 R14: 00000000004cb67f R15: 00007f588722a6d4
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci-upstream-kasan-gce	2020/06/18 09:01	upstream	7ae77150d94d	d45a4d69	.config	log	report