possible deadlock in sch_direct_xmit
From: Hao Sun <hidden>
Date: 2021-10-06 09:27:45
Also in:
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Hello, When using Healer to fuzz the latest Linux kernel, the following crash was triggered. HEAD commit: 42d43c92fc57 Merge branch 'for-linus' git tree: upstream console output: https://drive.google.com/file/d/16oeU35nvvz-aFIrGtltd6N0HHf6e6LXl/view?usp=sharing kernel config: https://drive.google.com/file/d/15vWoQRbJuuMu4ovWhUm1h4SrHyNwK8im/view?usp=sharing Sorry, I don't have a reproducer for this crash, hope the symbolized report can help. If you fix this issue, please add the following tag to the commit: Reported-by: Hao Sun <redacted> ============================================ WARNING: possible recursive locking detected 5.15.0-rc3+ #1 Not tainted -------------------------------------------- syz-executor/9686 is trying to acquire lock: ffff888013986498 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock ./include/linux/spinlock.h:363 [inline] ffff888013986498 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock ./include/linux/netdevice.h:4405 [inline] ffff888013986498 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x30f/0xc60 net/sched/sch_generic.c:340 but task is already holding lock: ffff888013984898 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock ./include/linux/spinlock.h:363 [inline] ffff888013984898 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock ./include/linux/netdevice.h:4405 [inline] ffff888013984898 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x30f/0xc60 net/sched/sch_generic.c:340 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(_xmit_ETHER#2); lock(_xmit_ETHER#2); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by syz-executor/9686: #0: ffffffff8b97e980 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect ./include/net/lwtunnel.h:95 [inline] #0: ffffffff8b97e980 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x295/0x21e0 net/ipv4/ip_output.c:207 #1: ffffffff8b97e980 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fc/0x3940 net/core/dev.c:4136 #2: ffff888021cd5258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock ./include/linux/spinlock.h:373 [inline] #2: ffff888021cd5258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin ./include/net/sch_generic.h:173 [inline] #2: ffff888021cd5258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3790 [inline] #2: ffff888021cd5258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x18bb/0x3940 net/core/dev.c:4170 #3: ffff888013984898 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock ./include/linux/spinlock.h:363 [inline] #3: ffff888013984898 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock ./include/linux/netdevice.h:4405 [inline] #3: ffff888013984898 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x30f/0xc60 net/sched/sch_generic.c:340 #4: ffffffff8b97e980 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect ./include/net/lwtunnel.h:95 [inline] #4: ffffffff8b97e980 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x295/0x21e0 net/ipv4/ip_output.c:207 #5: ffffffff8b97e980 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fc/0x3940 net/core/dev.c:4136 #6: ffff88810be44258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock ./include/linux/spinlock.h:373 [inline] #6: ffff88810be44258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin ./include/net/sch_generic.h:173 [inline] #6: ffff88810be44258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3790 [inline] #6: ffff88810be44258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x18bb/0x3940 net/core/dev.c:4170 stack backtrace: CPU: 0 PID: 9686 Comm: syz-executor Not tainted 5.15.0-rc3+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2944 [inline] check_deadlock kernel/locking/lockdep.c:2987 [inline] validate_chain kernel/locking/lockdep.c:3776 [inline] __lock_acquire.cold+0x168/0x3c3 kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x520 kernel/locking/lockdep.c:5590 __raw_spin_lock ./include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock ./include/linux/spinlock.h:363 [inline] __netif_tx_lock ./include/linux/netdevice.h:4405 [inline] sch_direct_xmit+0x30f/0xc60 net/sched/sch_generic.c:340 __dev_xmit_skb net/core/dev.c:3803 [inline] __dev_queue_xmit+0x1b05/0x3940 net/core/dev.c:4170 neigh_resolve_output net/core/neighbour.c:1492 [inline] neigh_resolve_output+0x52a/0x850 net/core/neighbour.c:1472 neigh_output ./include/net/neighbour.h:510 [inline] ip_finish_output2+0x873/0x21e0 net/ipv4/ip_output.c:221 __ip_finish_output net/ipv4/ip_output.c:299 [inline] __ip_finish_output+0x856/0x1450 net/ipv4/ip_output.c:281 ip_finish_output+0x32/0x200 net/ipv4/ip_output.c:309 NF_HOOK_COND ./include/linux/netfilter.h:296 [inline] ip_mc_output+0x268/0xec0 net/ipv4/ip_output.c:408 dst_output ./include/net/dst.h:450 [inline] ip_local_out+0xaf/0x1a0 net/ipv4/ip_output.c:126 iptunnel_xmit+0x69d/0xa90 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0xf79/0x2af0 net/ipv4/ip_tunnel.c:810 erspan_xmit+0x513/0x2ad0 net/ipv4/ip_gre.c:712 __netdev_start_xmit ./include/linux/netdevice.h:4988 [inline] netdev_start_xmit ./include/linux/netdevice.h:5002 [inline] xmit_one net/core/dev.c:3576 [inline] dev_hard_start_xmit+0x1ff/0x950 net/core/dev.c:3592 sch_direct_xmit+0x19f/0xc60 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3803 [inline] __dev_queue_xmit+0x1b05/0x3940 net/core/dev.c:4170 neigh_resolve_output net/core/neighbour.c:1492 [inline] neigh_resolve_output+0x52a/0x850 net/core/neighbour.c:1472 neigh_output ./include/net/neighbour.h:510 [inline] ip_finish_output2+0x873/0x21e0 net/ipv4/ip_output.c:221 __ip_finish_output net/ipv4/ip_output.c:299 [inline] __ip_finish_output+0x856/0x1450 net/ipv4/ip_output.c:281 ip_finish_output+0x32/0x200 net/ipv4/ip_output.c:309 NF_HOOK_COND ./include/linux/netfilter.h:296 [inline] ip_mc_output+0x268/0xec0 net/ipv4/ip_output.c:408 dst_output ./include/net/dst.h:450 [inline] ip_local_out+0xaf/0x1a0 net/ipv4/ip_output.c:126 ip_send_skb+0x3e/0xe0 net/ipv4/ip_output.c:1555 udp_send_skb.isra.0+0x6d2/0x11c0 net/ipv4/udp.c:966 udp_sendmsg+0x1d86/0x2820 net/ipv4/udp.c:1253 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:821 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x331/0x810 net/socket.c:2409 ___sys_sendmsg+0x100/0x170 net/socket.c:2463 __sys_sendmmsg+0x195/0x470 net/socket.c:2549 __do_sys_sendmmsg net/socket.c:2578 [inline] __se_sys_sendmmsg net/socket.c:2575 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2575 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f9c5d76cc4d Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9c5acd4c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f9c5d8930a0 RCX: 00007f9c5d76cc4d RDX: 000000000800001d RSI: 0000000020000100 RDI: 0000000000000003 RBP: 00007f9c5d7e5d80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9c5d8930a0 R13: 00007ffff72e0cbf R14: 00007ffff72e0e60 R15: 00007f9c5acd4dc0