================================ WARNING: inconsistent lock state 6.11.0-rc7-syzkaller-00133-ge936e7d4a83b #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. syz.4.314/6444 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff8880595989e0 (&pch->downl){+.?.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880595989e0 (&pch->downl){+.?.}-{2:2}, at: ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ffff8880595989e0 (&pch->downl){+.?.}-{2:2}, at: ppp_input+0x18b/0xa10 drivers/net/ppp/ppp_generic.c:2304 {SOFTIRQ-ON-W} state was registered at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ppp_input+0x18b/0xa10 drivers/net/ppp/ppp_generic.c:2304 pppoe_rcv_core+0x117/0x310 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv include/net/sock.h:1111 [inline] __release_sock+0x245/0x350 net/core/sock.c:3004 release_sock+0x61/0x1f0 net/core/sock.c:3558 pppoe_sendmsg+0xd5/0x750 drivers/net/ppp/pppoe.c:903 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x223/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737 __do_sys_sendmmsg net/socket.c:2766 [inline] __se_sys_sendmmsg net/socket.c:2763 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763 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 irq event stamp: 6030 hardirqs last enabled at (6030): [] __local_bh_enable_ip+0x168/0x200 kernel/softirq.c:387 hardirqs last disabled at (6029): [] __local_bh_enable_ip+0x106/0x200 kernel/softirq.c:364 softirqs last enabled at (6008): [] pppoe_sendmsg+0xd5/0x750 drivers/net/ppp/pppoe.c:903 softirqs last disabled at (6009): [] do_softirq+0x11b/0x1e0 kernel/softirq.c:455 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&pch->downl); lock(&pch->downl); *** DEADLOCK *** 4 locks held by syz.4.314/6444: #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6104 #1: ffff8880611021d8 (slock-AF_PPPOX){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #1: ffff8880611021d8 (slock-AF_PPPOX){+.-.}-{2:2}, at: __sk_receive_skb+0x18c/0x8b0 net/core/sock.c:562 #2: ffff888061102258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: __netif_receive_skb_one_core net/core/dev.c:5661 [inline] #2: ffff888061102258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: __netif_receive_skb+0x2e2/0x650 net/core/dev.c:5775 #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2267 [inline] #3: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: ppp_input+0x55/0xa10 drivers/net/ppp/ppp_generic.c:2304 stack backtrace: CPU: 1 UID: 0 PID: 6444 Comm: syz.4.314 Not tainted 6.11.0-rc7-syzkaller-00133-ge936e7d4a83b #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 valid_state+0x13a/0x1c0 kernel/locking/lockdep.c:4012 mark_lock_irq+0xbb/0xc20 kernel/locking/lockdep.c:4215 mark_lock+0x223/0x350 kernel/locking/lockdep.c:4677 __lock_acquire+0xbf9/0x2040 kernel/locking/lockdep.c:5096 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ppp_input+0x18b/0xa10 drivers/net/ppp/ppp_generic.c:2304 pppoe_rcv_core+0x117/0x310 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv include/net/sock.h:1111 [inline] __sk_receive_skb+0x82d/0x8b0 net/core/sock.c:569 __netif_receive_skb_one_core net/core/dev.c:5661 [inline] __netif_receive_skb+0x2e2/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6108 __napi_poll+0xcd/0x490 net/core/dev.c:6772 napi_poll net/core/dev.c:6841 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6963 handle_softirqs+0x2c6/0x970 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 pppoe_sendmsg+0xd5/0x750 drivers/net/ppp/pppoe.c:903 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x223/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737 __do_sys_sendmmsg net/socket.c:2766 [inline] __se_sys_sendmmsg net/socket.c:2763 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763 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: 0033:0x7f86ded7def9 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:00007f86dfc58038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f86def35f80 RCX: 00007f86ded7def9 RDX: 0400000000000026 RSI: 0000000020001cc0 RDI: 0000000000000003 RBP: 00007f86dedf0b76 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f86def35f80 R15: 00007ffca2b2b068