WARNING in mptcp_pm_nl_set

WARNING in mptcp_pm_nl_set_flags (2)

Status: upstream: reported syz repro on 2025/01/14 18:26
Subsystems: mptcp
[Documentation on labels]
Reported-by: syzbot+cd16e79c1e45f3fe0377@syzkaller.appspotmail.com
Fix commit: 1bb0d1348546 mptcp: pm: only set fullmesh for subflow endp
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu2-arm32]
First crash: 82d, last: 81d

Cause bisection: introduced by (bisect log) :
commit 322ea3778965da72862cca2a0c50253aacf65fe6
Author: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Date: Mon Aug 19 19:45:26 2024 +0000

mptcp: pm: only mark 'subflow' endp as available

Crash: WARNING in mptcp_pm_nl_set_flags (log)
Repro: syz .config

▶ ▼ Discussions (3)

Title	Replies (including bot)	Last reply
[PATCH net 0/3] mptcp: fixes addressing syzbot reports	5 (5)	2025/01/28 00:00
[syzbot] [mptcp?] WARNING in mptcp_pm_nl_set_flags (2)	0 (2)	2025/01/24 13:43
[syzbot] Monthly mptcp report (Jan 2025)	0 (1)	2025/01/16 13:07

▶ ▼ Similar bugs (1)

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	WARNING in mptcp_pm_nl_set_flags mptcp	syz	done		3	218d	218d	28/28	fixed on 2024/10/22 11:57

▶ ▼ Last patch testing requests (1)


Created	Duration	User	Patch	Repo	Result
2025/01/24 02:23	47m	retest repro		net	error

Sample crash report:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 __mark_subflow_endp_available net/mptcp/pm_netlink.c:1496 [inline]
WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_pm_nl_fullmesh net/mptcp/pm_netlink.c:1980 [inline]
WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_nl_set_flags net/mptcp/pm_netlink.c:2003 [inline]
WARNING: CPU: 0 PID: 6499 at net/mptcp/pm_netlink.c:1496 mptcp_pm_nl_set_flags+0x974/0xdc0 net/mptcp/pm_netlink.c:2064
Modules linked in:
CPU: 0 UID: 0 PID: 6499 Comm: syz.1.413 Not tainted 6.13.0-rc5-syzkaller-00172-gd1bf27c4e176 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:__mark_subflow_endp_available net/mptcp/pm_netlink.c:1496 [inline]
RIP: 0010:mptcp_pm_nl_fullmesh net/mptcp/pm_netlink.c:1980 [inline]
RIP: 0010:mptcp_nl_set_flags net/mptcp/pm_netlink.c:2003 [inline]
RIP: 0010:mptcp_pm_nl_set_flags+0x974/0xdc0 net/mptcp/pm_netlink.c:2064
Code: 01 00 00 49 89 c5 e8 fb 45 e8 f5 e9 b8 fc ff ff e8 f1 45 e8 f5 4c 89 f7 be 03 00 00 00 e8 44 1d 0b f9 eb a0 e8 dd 45 e8 f5 90 <0f> 0b 90 e9 17 ff ff ff 89 d9 80 e1 07 38 c1 0f 8c c9 fc ff ff 48
RSP: 0018:ffffc9000d307240 EFLAGS: 00010293
RAX: ffffffff8bb72e03 RBX: 0000000000000000 RCX: ffff88807da88000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000d307430 R08: ffffffff8bb72cf0 R09: 1ffff1100b842a5e
R10: dffffc0000000000 R11: ffffed100b842a5f R12: ffff88801e2e5ac0
R13: ffff88805c214800 R14: ffff88805c2152e8 R15: 1ffff1100b842a5d
FS:  00005555619f6500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020002840 CR3: 00000000247e6000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2542
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1347
 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1891
 sock_sendmsg_nosec net/socket.c:711 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:726
 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583
 ___sys_sendmsg net/socket.c:2637 [inline]
 __sys_sendmsg+0x269/0x350 net/socket.c:2669
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5fe8785d29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff571f5558 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f5fe8975fa0 RCX: 00007f5fe8785d29
RDX: 0000000000000000 RSI: 0000000020000480 RDI: 0000000000000007
RBP: 00007f5fe8801b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5fe8975fa0 R14: 00007f5fe8975fa0 R15: 00000000000011f4
 </TASK>

Crashes (2):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2025/01/09 23:22	net	d1bf27c4e176	40f46913	.config	console log	report	syz / log			[disk image] [vmlinux] [kernel image]	ci-upstream-net-this-kasan-gce	WARNING in mptcp_pm_nl_set_flags
2025/01/09 11:43	net	d1bf27c4e176	f3558dbf	.config	console log	report			info	[disk image] [vmlinux] [kernel image]	ci-upstream-net-this-kasan-gce	WARNING in mptcp_pm_nl_set_flags

* ~~Struck through~~ repros no longer work on HEAD.