============================================ WARNING: possible recursive locking detected 6.8.0-syzkaller-05204-g237bb5f7f7f5 #0 Not tainted -------------------------------------------- dhcpcd/13947 is trying to acquire lock: ffff88802d5693e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88802d5693e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3523 [inline] ffff88802d5693e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3919 [inline] ffff88802d5693e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_rcv+0x30e2/0x8180 net/bridge/br_multicast.c:3974 but task is already holding lock: ffff888022d153e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff888022d153e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x64/0x3b0 net/bridge/br_multicast.c:1905 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&br->multicast_lock); lock(&br->multicast_lock); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by dhcpcd/13947: #0: ffff888022a88c08 (&sig->cred_guard_mutex){+.+.}-{3:3}, at: prepare_bprm_creds fs/exec.c:1493 [inline] #0: ffff888022a88c08 (&sig->cred_guard_mutex){+.+.}-{3:3}, at: bprm_execve+0xd1/0x1790 fs/exec.c:1851 #1: ffffffff8e797d30 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:116 [inline] #1: ffffffff8e797d30 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:215 [inline] #1: ffffffff8e797d30 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1108 [inline] #1: ffffffff8e797d30 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_bprm_check_security+0xe9/0x180 security/tomoyo/tomoyo.c:101 #2: ffffc90000a08c00 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x600 kernel/time/timer.c:1789 #3: ffff888022d153e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #3: ffff888022d153e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x64/0x3b0 net/bridge/br_multicast.c:1905 #4: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #4: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline] #4: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260 #5: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #5: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline] #5: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260 #6: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #6: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #6: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: br_dev_xmit+0x1b9/0x1a10 net/bridge/br_device.c:44 stack backtrace: CPU: 1 PID: 13947 Comm: dhcpcd Not tainted 6.8.0-syzkaller-05204-g237bb5f7f7f5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __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] br_ip6_multicast_query net/bridge/br_multicast.c:3523 [inline] br_multicast_ipv6_rcv net/bridge/br_multicast.c:3919 [inline] br_multicast_rcv+0x30e2/0x8180 net/bridge/br_multicast.c:3974 br_dev_xmit+0xb17/0x1a10 net/bridge/br_device.c:90 __netdev_start_xmit include/linux/netdevice.h:4903 [inline] netdev_start_xmit include/linux/netdevice.h:4917 [inline] xmit_one net/core/dev.c:3531 [inline] dev_hard_start_xmit+0x26a/0x790 net/core/dev.c:3547 __dev_queue_xmit+0x19f4/0x3b10 net/core/dev.c:4335 dev_queue_xmit include/linux/netdevice.h:3091 [inline] vlan_dev_hard_start_xmit+0x36c/0x5f0 net/8021q/vlan_dev.c:125 __netdev_start_xmit include/linux/netdevice.h:4903 [inline] netdev_start_xmit include/linux/netdevice.h:4917 [inline] xmit_one net/core/dev.c:3531 [inline] dev_hard_start_xmit+0x26a/0x790 net/core/dev.c:3547 __dev_queue_xmit+0x19f4/0x3b10 net/core/dev.c:4335 dev_queue_xmit include/linux/netdevice.h:3091 [inline] br_dev_queue_push_xmit+0x701/0x8d0 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:314 [inline] __br_multicast_send_query+0x2ecb/0x4750 net/bridge/br_multicast.c:1809 br_multicast_send_query+0x4ee/0x6b0 net/bridge/br_multicast.c:1888 br_multicast_port_query_expired+0x2d4/0x3b0 net/bridge/br_multicast.c:1913 call_timer_fn+0x17e/0x600 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers kernel/time/timer.c:2408 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2419 run_timer_base kernel/time/timer.c:2428 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2438 __do_softirq+0x2bc/0x943 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:tomoyo_fill_path_info+0x2eb/0x3a0 security/tomoyo/util.c:684 Code: 5c 24 0e 41 0f b7 df 89 df 89 ee e8 af dc 38 fd 39 eb 0f 9c c3 49 8d 7c 24 0f 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 71 <41> 88 5c 24 0f 31 ff 4c 89 ee 89 ea e8 c4 25 b0 fd 89 c3 49 83 c4 RSP: 0018:ffffc90003527a18 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888079c63c00 RDX: ffff888079c63c00 RSI: 0000000000000004 RDI: ffffc90003527aaf RBP: 0000000000000004 R08: ffffffff845c1581 R09: ffffffff845c134c R10: 0000000000000002 R11: ffff888079c63c00 R12: ffffc90003527aa0 R13: ffff88802b774000 R14: dffffc0000000000 R15: 0000000000000004 tomoyo_env_perm+0xf5/0x210 security/tomoyo/environ.c:58 tomoyo_environ security/tomoyo/domain.c:672 [inline] tomoyo_find_next_domain+0x1384/0x1cf0 security/tomoyo/domain.c:878 tomoyo_bprm_check_security+0x115/0x180 security/tomoyo/tomoyo.c:102 security_bprm_check+0x66/0xa0 security/security.c:1188 search_binary_handler fs/exec.c:1765 [inline] exec_binprm fs/exec.c:1819 [inline] bprm_execve+0xa56/0x1790 fs/exec.c:1871 do_execveat_common+0x553/0x700 fs/exec.c:1978 do_execve fs/exec.c:2052 [inline] __do_sys_execve fs/exec.c:2128 [inline] __se_sys_execve fs/exec.c:2123 [inline] __x64_sys_execve+0x92/0xb0 fs/exec.c:2123 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7fd6e120fef7 Code: ba 0f 00 5b 5d 41 5c 41 5d 41 5e 41 5f e9 63 d8 fb ff 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 66 90 b8 3b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 01 3f 0f 00 f7 d8 64 89 01 48 RSP: 002b:00007fd6e10b9e78 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00007ffff0dd0740 RCX: 00007fd6e120fef7 RDX: 000055ba95ef21e0 RSI: 00007ffff0dd0c30 RDI: 000055ba6105cdf6 RBP: 00007fd6e10b9ff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffff0dd0a58 R13: 00007fd6e10b9f28 R14: 0000000000000000 R15: 0000000000000041 ---------------- Code disassembly (best guess): 0: 5c pop %rsp 1: 24 0e and $0xe,%al 3: 41 0f b7 df movzwl %r15w,%ebx 7: 89 df mov %ebx,%edi 9: 89 ee mov %ebp,%esi b: e8 af dc 38 fd call 0xfd38dcbf 10: 39 eb cmp %ebp,%ebx 12: 0f 9c c3 setl %bl 15: 49 8d 7c 24 0f lea 0xf(%r12),%rdi 1a: 48 89 f8 mov %rdi,%rax 1d: 48 c1 e8 03 shr $0x3,%rax 21: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax 26: 84 c0 test %al,%al 28: 75 71 jne 0x9b * 2a: 41 88 5c 24 0f mov %bl,0xf(%r12) <-- trapping instruction 2f: 31 ff xor %edi,%edi 31: 4c 89 ee mov %r13,%rsi 34: 89 ea mov %ebp,%edx 36: e8 c4 25 b0 fd call 0xfdb025ff 3b: 89 c3 mov %eax,%ebx 3d: 49 rex.WB 3e: 83 .byte 0x83 3f: c4 .byte 0xc4