================================ WARNING: inconsistent lock state 6.12.0-rc1-syzkaller-00046-g7ec462100ef9 #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. syz-executor/5340 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff88806ffdf1e0 (&pch->downl){+.?.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88806ffdf1e0 (&pch->downl){+.?.}-{2:2}, at: ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ffff88806ffdf1e0 (&pch->downl){+.?.}-{2:2}, at: ppp_input+0x104/0xbb0 drivers/net/ppp/ppp_generic.c:2304 {SOFTIRQ-ON-W} state was registered at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __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+0x104/0xbb0 drivers/net/ppp/ppp_generic.c:2304 pppoe_rcv_core+0x22c/0x320 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv include/net/sock.h:1113 [inline] __release_sock+0x35f/0x400 net/core/sock.c:3072 release_sock+0x5a/0x220 net/core/sock.c:3626 pppoe_sendmsg+0x625/0x7c0 drivers/net/ppp/pppoe.c:903 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg net/socket.c:744 [inline] ____sys_sendmsg+0x9ae/0xb40 net/socket.c:2602 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2656 __sys_sendmmsg+0x2a5/0x450 net/socket.c:2735 __compat_sys_sendmmsg net/compat.c:360 [inline] __do_compat_sys_sendmmsg net/compat.c:367 [inline] __se_compat_sys_sendmmsg net/compat.c:364 [inline] __ia32_compat_sys_sendmmsg+0x9d/0x100 net/compat.c:364 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e irq event stamp: 2771622 hardirqs last enabled at (2771622): [] __local_bh_enable_ip+0xa4/0x120 kernel/softirq.c:387 hardirqs last disabled at (2771621): [] __local_bh_enable_ip+0xcd/0x120 kernel/softirq.c:364 softirqs last enabled at (2770952): [] softirq_handle_end kernel/softirq.c:400 [inline] softirqs last enabled at (2770952): [] handle_softirqs+0x5bb/0x8f0 kernel/softirq.c:582 softirqs last disabled at (2771569): [] __do_softirq kernel/softirq.c:588 [inline] softirqs last disabled at (2771569): [] invoke_softirq kernel/softirq.c:428 [inline] softirqs last disabled at (2771569): [] __irq_exit_rcu kernel/softirq.c:637 [inline] softirqs last disabled at (2771569): [] irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649 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-executor/5340: #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: local_lock_release include/linux/local_lock_internal.h:38 [inline] #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x3f1/0x15f0 net/core/dev.c:6105 #1: ffff888012c2f1d8 (slock-AF_PPPOX){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #1: ffff888012c2f1d8 (slock-AF_PPPOX){+.-.}-{2:2}, at: __sk_receive_skb+0x1dd/0x890 net/core/sock.c:563 #2: ffff888012c2f258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: sk_receive_skb include/net/sock.h:1898 [inline] #2: ffff888012c2f258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: pppoe_rcv+0x7b2/0xa70 drivers/net/ppp/pppoe.c:451 #3: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #3: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2267 [inline] #3: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: ppp_input+0x70/0xbb0 drivers/net/ppp/ppp_generic.c:2304 stack backtrace: CPU: 0 UID: 0 PID: 5340 Comm: syz-executor Not tainted 6.12.0-rc1-syzkaller-00046-g7ec462100ef9 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_usage_bug.part.0+0x3a2/0x560 kernel/locking/lockdep.c:4038 print_usage_bug kernel/locking/lockdep.c:4006 [inline] valid_state kernel/locking/lockdep.c:4052 [inline] mark_lock_irq kernel/locking/lockdep.c:4263 [inline] mark_lock+0x92d/0xc60 kernel/locking/lockdep.c:4725 mark_usage kernel/locking/lockdep.c:4614 [inline] __lock_acquire+0x11e1/0x3ce0 kernel/locking/lockdep.c:5156 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 __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+0x104/0xbb0 drivers/net/ppp/ppp_generic.c:2304 pppoe_rcv_core+0x22c/0x320 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv include/net/sock.h:1113 [inline] __sk_receive_skb+0x7aa/0x890 net/core/sock.c:570 sk_receive_skb include/net/sock.h:1898 [inline] pppoe_rcv+0x7b2/0xa70 drivers/net/ppp/pppoe.c:451 __netif_receive_skb_one_core+0x1b1/0x1e0 net/core/dev.c:5662 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5775 process_backlog+0x443/0x15f0 net/core/dev.c:6107 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0xa92/0x1010 net/core/dev.c:6962 handle_softirqs+0x213/0x8f0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline] sysvec_apic_timer_interrupt+0x57/0xc0 arch/x86/kernel/apic/apic.c:1037 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0023:0xf719e225 Code: 83 c4 0c 68 01 00 00 40 ff 74 24 10 6a ff e8 82 ff 11 00 83 c4 10 39 04 24 0f 84 99 01 00 00 b8 03 00 00 00 f7 a6 a4 95 b6 00 <8b> be a8 95 b6 00 8d 3c 7f 89 d3 89 c1 01 fb 89 c7 b8 cd cc cc cc RSP: 002b:00000000ffc043f0 EFLAGS: 00000202 RAX: 0000000000003a98 RBX: 00000000f746bff4 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00000000f746bff4 RDI: 00000000000545df RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 83 c4 0c add $0xc,%esp 3: 68 01 00 00 40 push $0x40000001 8: ff 74 24 10 push 0x10(%rsp) c: 6a ff push $0xffffffffffffffff e: e8 82 ff 11 00 call 0x11ff95 13: 83 c4 10 add $0x10,%esp 16: 39 04 24 cmp %eax,(%rsp) 19: 0f 84 99 01 00 00 je 0x1b8 1f: b8 03 00 00 00 mov $0x3,%eax 24: f7 a6 a4 95 b6 00 mull 0xb695a4(%rsi) * 2a: 8b be a8 95 b6 00 mov 0xb695a8(%rsi),%edi <-- trapping instruction 30: 8d 3c 7f lea (%rdi,%rdi,2),%edi 33: 89 d3 mov %edx,%ebx 35: 89 c1 mov %eax,%ecx 37: 01 fb add %edi,%ebx 39: 89 c7 mov %eax,%edi 3b: b8 cd cc cc cc mov $0xcccccccd,%eax