================================ WARNING: inconsistent lock state 6.11.0-syzkaller-08829-gaf9c191ac2a0 #0 Not tainted -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. syz.0.831/11009 [HC0[0]:SC0[0]:HE1:SE1] takes: ffff88804d8a19e0 (&pch->downl){+.?.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88804d8a19e0 (&pch->downl){+.?.}-{2:2}, at: ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2272 [inline] ffff88804d8a19e0 (&pch->downl){+.?.}-{2:2}, at: ppp_input+0x18b/0xa10 drivers/net/ppp/ppp_generic.c:2304 {IN-SOFTIRQ-W} state was registered at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822 __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_push+0x31/0x1e0 drivers/net/ppp/ppp_generic.c:2161 ppp_channel_push+0x196/0x220 drivers/net/ppp/ppp_generic.c:2192 tasklet_action_common+0x321/0x4d0 kernel/softirq.c:784 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 irq event stamp: 563 hardirqs last enabled at (563): [] __local_bh_enable_ip+0x168/0x200 kernel/softirq.c:387 hardirqs last disabled at (561): [] __local_bh_enable_ip+0x106/0x200 kernel/softirq.c:364 softirqs last enabled at (562): [] spin_unlock_bh include/linux/spinlock.h:396 [inline] softirqs last enabled at (562): [] __release_sock+0x9a/0x350 net/core/sock.c:3065 softirqs last disabled at (560): [] spin_lock_bh include/linux/spinlock.h:356 [inline] softirqs last disabled at (560): [] release_sock+0x30/0x1f0 net/core/sock.c:3624 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&pch->downl); lock(&pch->downl); *** DEADLOCK *** 2 locks held by syz.0.831/11009: #0: ffff888071322258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1609 [inline] #0: ffff888071322258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: pppoe_sendmsg+0x51/0x750 drivers/net/ppp/pppoe.c:849 #1: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #1: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2267 [inline] #1: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: ppp_input+0x55/0xa10 drivers/net/ppp/ppp_generic.c:2304 stack backtrace: CPU: 1 UID: 0 PID: 11009 Comm: syz.0.831 Not tainted 6.11.0-syzkaller-08829-gaf9c191ac2a0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 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:4035 valid_state+0x13a/0x1c0 kernel/locking/lockdep.c:4049 mark_lock_irq+0xbb/0xc20 kernel/locking/lockdep.c:4260 mark_lock+0x223/0x360 kernel/locking/lockdep.c:4722 __lock_acquire+0x11b0/0x2050 kernel/locking/lockdep.c:5153 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822 __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:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2603 ___sys_sendmsg net/socket.c:2657 [inline] __sys_sendmmsg+0x3ac/0x730 net/socket.c:2743 __do_sys_sendmmsg net/socket.c:2772 [inline] __se_sys_sendmmsg net/socket.c:2769 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2769 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: 0033:0x7f33fb97def9 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:00007f33fc6f9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f33fbb35f80 RCX: 00007f33fb97def9 RDX: 0400000000000026 RSI: 0000000020001cc0 RDI: 0000000000000005 RBP: 00007f33fb9f0b76 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f33fbb35f80 R15: 00007f33fbc5fa28