cdc_wdm 4-1:1.0: wdm_int_callback - 0 bytes ================================ WARNING: inconsistent lock state 6.12.0-rc1-syzkaller-00042-gf23aa4c0761a #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. syz-executor/17387 [HC0[0]:SC1[3]:HE1:SE0] takes: ffff88805eb729e0 (&pch->downl){+.?.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88805eb729e0 (&pch->downl){+.?.}-{2:2}, at: __ppp_channel_push+0x31/0x1e0 drivers/net/ppp/ppp_generic.c:2161 {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+0x4a8/0x730 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+0xa2/0xc0 net/compat.c:364 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/common.c:386 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e irq event stamp: 718518 hardirqs last enabled at (718518): [] __local_bh_enable_ip+0x168/0x200 kernel/softirq.c:387 hardirqs last disabled at (718517): [] __local_bh_enable_ip+0x106/0x200 kernel/softirq.c:364 softirqs last enabled at (718492): [] copy_fpstate_to_sigframe+0x179/0xdc0 softirqs last disabled at (718493): [] 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 *** 1 lock held by syz-executor/17387: #0: ffff88805eb72a48 (&pch->upl){++.-}-{2:2}, at: ppp_channel_push+0x2c/0x220 drivers/net/ppp/ppp_generic.c:2186 stack backtrace: CPU: 0 UID: 0 PID: 17387 Comm: syz-executor Not tainted 6.12.0-rc1-syzkaller-00042-gf23aa4c0761a #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_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 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:80 [inline] copy_fpstate_to_sigframe+0x4d5/0xdc0 arch/x86/kernel/fpu/signal.c:250 get_sigframe+0x5d9/0x800 arch/x86/kernel/signal.c:163 ia32_setup_frame+0x123/0xa00 arch/x86/kernel/signal_32.c:249 setup_rt_frame arch/x86/kernel/signal.c:246 [inline] handle_signal arch/x86/kernel/signal.c:294 [inline] arch_do_signal_or_restart+0x480/0x860 arch/x86/kernel/signal.c:339 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 __do_fast_syscall_32+0xc4/0x110 arch/x86/entry/common.c:389 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7fb1579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f759fcd0 EFLAGS: 00000206 ORIG_RAX: 000000000000010b RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 00000000f759fd04 RSI: 00000000f759fcfc RDI: 00000000f759fd04 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 cdc_wdm 4-1:1.0: wdm_int_callback - usb_submit_urb failed with result -19 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 90 nop 33: 90 nop 34: 90 nop 35: 90 nop 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop