================================ WARNING: inconsistent lock state 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7 #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. syz.2.465/6977 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff8880626739e0 (&pch->downl){+.?.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880626739e0 (&pch->downl){+.?.}-{2:2}, at: ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ffff8880626739e0 (&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: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+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:1113 [inline] __release_sock+0x243/0x350 net/core/sock.c:3072 release_sock+0x61/0x1f0 net/core/sock.c:3626 pppoe_sendmsg+0xd5/0x750 drivers/net/ppp/pppoe.c:903 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:744 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2602 ___sys_sendmsg net/socket.c:2656 [inline] __sys_sendmmsg+0x3ab/0x730 net/socket.c:2742 __do_sys_sendmmsg net/socket.c:2771 [inline] __se_sys_sendmmsg net/socket.c:2768 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2768 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: 3546 hardirqs last enabled at (3546): [] __local_bh_enable_ip+0x168/0x200 kernel/softirq.c:387 hardirqs last disabled at (3545): [] __local_bh_enable_ip+0x106/0x200 kernel/softirq.c:364 softirqs last enabled at (3440): [] pppoe_sendmsg+0xd5/0x750 drivers/net/ppp/pppoe.c:903 softirqs last disabled at (3519): [] __do_softirq kernel/softirq.c:588 [inline] softirqs last disabled at (3519): [] invoke_softirq kernel/softirq.c:428 [inline] softirqs last disabled at (3519): [] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&pch->downl); lock(&pch->downl); *** DEADLOCK *** 5 locks held by syz.2.465/6977: #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: path_init+0x12a/0x1360 fs/namei.c:2451 #1: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #1: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x33b/0x15b0 net/core/dev.c:6103 #2: ffff88804297f1d8 (slock-AF_PPPOX){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffff88804297f1d8 (slock-AF_PPPOX){+.-.}-{2:2}, at: __sk_receive_skb+0x18c/0x8b0 net/core/sock.c:563 #3: ffff88804297f258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: __netif_receive_skb_one_core net/core/dev.c:5662 [inline] #3: ffff88804297f258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: __netif_receive_skb+0x2e0/0x650 net/core/dev.c:5775 #4: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #4: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #4: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2267 [inline] #4: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: ppp_input+0x55/0xa10 drivers/net/ppp/ppp_generic.c:2304 stack backtrace: CPU: 0 UID: 0 PID: 6977 Comm: syz.2.465 Not tainted 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_usage_bug+0x62e/0x8b0 kernel/locking/lockdep.c:4038 valid_state+0x13a/0x1c0 kernel/locking/lockdep.c:4052 mark_lock_irq+0xbb/0xc20 kernel/locking/lockdep.c:4263 mark_lock+0x223/0x360 kernel/locking/lockdep.c:4725 __lock_acquire+0xbf9/0x2050 kernel/locking/lockdep.c:5156 lock_acquire+0x1ed/0x550 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+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:1113 [inline] __sk_receive_skb+0x82b/0x8b0 net/core/sock.c:570 __netif_receive_skb_one_core net/core/dev.c:5662 [inline] __netif_receive_skb+0x2e0/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6107 __napi_poll+0xcb/0x490 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6962 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1037 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:seqcount_lockdep_reader_access+0x1d6/0x220 include/linux/seqlock.h:75 Code: 62 e8 3e 7b 7f ff 4d 85 f6 48 bb 00 00 00 00 00 fc ff df 75 07 e8 2a 7b 7f ff eb 06 e8 23 7b 7f ff fb 48 c7 04 24 0e 36 e0 45 <4a> c7 04 23 00 00 00 00 66 42 c7 44 23 09 00 00 42 c6 44 23 0b 00 RSP: 0018:ffffc90003ddf7c0 EFLAGS: 00000287 RAX: ffffffff8215608d RBX: dffffc0000000000 RCX: 0000000000040000 RDX: ffffc90005362000 RSI: 000000000000005e RDI: 000000000000005f RBP: ffffc90003ddf870 R08: ffffffff82156068 R09: 1ffffffff2039ccd R10: dffffc0000000000 R11: fffffbfff2039cce R12: 1ffff920007bbef8 R13: ffffc90003ddf7e0 R14: 0000000000000200 R15: 0000000000000046 path_init+0x833/0x1360 fs/namei.c:2495 path_openat+0x1a4/0x3590 fs/namei.c:3928 do_filp_open+0x235/0x490 fs/namei.c:3960 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1441 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: 0033:0x7fd3fa57dff9 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:00007fd3fb314038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fd3fa735f80 RCX: 00007fd3fa57dff9 RDX: 000000000000275a RSI: 0000000020000240 RDI: ffffffffffffff9c RBP: 00007fd3fa5f0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd3fa735f80 R15: 00007fd3fa85fa28 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: e8 3e 7b 7f ff call 0xff7f7b43 5: 4d 85 f6 test %r14,%r14 8: 48 bb 00 00 00 00 00 movabs $0xdffffc0000000000,%rbx f: fc ff df 12: 75 07 jne 0x1b 14: e8 2a 7b 7f ff call 0xff7f7b43 19: eb 06 jmp 0x21 1b: e8 23 7b 7f ff call 0xff7f7b43 20: fb sti 21: 48 c7 04 24 0e 36 e0 movq $0x45e0360e,(%rsp) 28: 45 * 29: 4a c7 04 23 00 00 00 movq $0x0,(%rbx,%r12,1) <-- trapping instruction 30: 00 31: 66 42 c7 44 23 09 00 movw $0x0,0x9(%rbx,%r12,1) 38: 00 39: 42 c6 44 23 0b 00 movb $0x0,0xb(%rbx,%r12,1)