============================================ WARNING: possible recursive locking detected 6.11.0-rc6-syzkaller-00019-g67784a74e258-dirty #0 Not tainted -------------------------------------------- syz.1.16/6115 is trying to acquire lock: ffff888028c116a0 (&msk->pm.lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888028c116a0 (&msk->pm.lock){+.-.}-{2:2}, at: mptcp_pm_del_add_timer net/mptcp/pm_netlink.c:338 [inline] ffff888028c116a0 (&msk->pm.lock){+.-.}-{2:2}, at: remove_anno_list_by_saddr+0x24/0x190 net/mptcp/pm_netlink.c:1464 but task is already holding lock: ffff888028c116a0 (&msk->pm.lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888028c116a0 (&msk->pm.lock){+.-.}-{2:2}, at: mptcp_pm_remove_addrs_and_subflows net/mptcp/pm_netlink.c:1682 [inline] ffff888028c116a0 (&msk->pm.lock){+.-.}-{2:2}, at: mptcp_nl_remove_addrs_list net/mptcp/pm_netlink.c:1719 [inline] ffff888028c116a0 (&msk->pm.lock){+.-.}-{2:2}, at: mptcp_pm_nl_flush_addrs_doit+0x509/0xd80 net/mptcp/pm_netlink.c:1760 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&msk->pm.lock); lock(&msk->pm.lock); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by syz.1.16/6115: #0: ffffffff8fcf14b0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8fcf1368 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8fcf1368 (genl_mutex){+.+.}-{3:3}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8fcf1368 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x121/0xec0 net/netlink/genetlink.c:1209 #2: ffff888028c10e98 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #2: ffff888028c10e98 (sk_lock-AF_INET6){+.+.}-{0:0}, at: mptcp_nl_remove_addrs_list net/mptcp/pm_netlink.c:1718 [inline] #2: ffff888028c10e98 (sk_lock-AF_INET6){+.+.}-{0:0}, at: mptcp_pm_nl_flush_addrs_doit+0x4d0/0xd80 net/mptcp/pm_netlink.c:1760 #3: ffff888028c116a0 (&msk->pm.lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #3: ffff888028c116a0 (&msk->pm.lock){+.-.}-{2:2}, at: mptcp_pm_remove_addrs_and_subflows net/mptcp/pm_netlink.c:1682 [inline] #3: ffff888028c116a0 (&msk->pm.lock){+.-.}-{2:2}, at: mptcp_nl_remove_addrs_list net/mptcp/pm_netlink.c:1719 [inline] #3: ffff888028c116a0 (&msk->pm.lock){+.-.}-{2:2}, at: mptcp_pm_nl_flush_addrs_doit+0x509/0xd80 net/mptcp/pm_netlink.c:1760 stack backtrace: CPU: 0 UID: 0 PID: 6115 Comm: syz.1.16 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_deadlock kernel/locking/lockdep.c:3061 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] mptcp_pm_del_add_timer net/mptcp/pm_netlink.c:338 [inline] remove_anno_list_by_saddr+0x24/0x190 net/mptcp/pm_netlink.c:1464 mptcp_pm_remove_addrs_and_subflows net/mptcp/pm_netlink.c:1689 [inline] mptcp_nl_remove_addrs_list net/mptcp/pm_netlink.c:1719 [inline] mptcp_pm_nl_flush_addrs_doit+0x689/0xd80 net/mptcp/pm_netlink.c:1760 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:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2680 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: 0033:0x7fb336579eb9 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:00007fb3372d5038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fb336715f80 RCX: 00007fb336579eb9 RDX: 0000000001000000 RSI: 0000000020000300 RDI: 0000000000000003 RBP: 00007fb3365e793e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb336715f80 R15: 00007fb33683fa28