============================================ WARNING: possible recursive locking detected 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted -------------------------------------------- syz-executor.3/5099 is trying to acquire lock: ffff8880110ceda0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff8880110ceda0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: hsr_dev_xmit+0x13e/0x1d0 net/hsr/hsr_device.c:229 but task is already holding lock: ffff88807c4feda0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88807c4feda0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: send_hsr_supervision_frame+0x276/0xad0 net/hsr/hsr_device.c:310 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&hsr->seqnr_lock); lock(&hsr->seqnr_lock); *** DEADLOCK *** May be due to missing lock nesting notation 15 locks held by syz-executor.3/5099: #0: ffffffff8e1dbab0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:637 [inline] #0: ffffffff8e1dbab0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1687 [inline] #0: ffffffff8e1dbab0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x272/0x21b0 kernel/fork.c:1736 #1: ffff88807c25d720 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #1: ffff88807c25d720 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:638 [inline] #1: ffff88807c25d720 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1687 [inline] #1: ffff88807c25d720 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x292/0x21b0 kernel/fork.c:1736 #2: ffff88801e5e73a0 (&mm->mmap_lock/1){+.+.}-{3:3}, at: mmap_write_lock_nested include/linux/mmap_lock.h:115 [inline] #2: ffff88801e5e73a0 (&mm->mmap_lock/1){+.+.}-{3:3}, at: dup_mmap kernel/fork.c:647 [inline] #2: ffff88801e5e73a0 (&mm->mmap_lock/1){+.+.}-{3:3}, at: dup_mm kernel/fork.c:1687 [inline] #2: ffff88801e5e73a0 (&mm->mmap_lock/1){+.+.}-{3:3}, at: copy_mm+0x3cc/0x21b0 kernel/fork.c:1736 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: __pte_offset_map+0x82/0x380 mm/pgtable-generic.c:285 #4: ffff88801fb60378 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #4: ffff88801fb60378 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: __pte_offset_map_lock+0x1ba/0x300 mm/pgtable-generic.c:373 #5: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #5: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #5: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: __pte_offset_map+0x82/0x380 mm/pgtable-generic.c:285 #6: ffff88806029a258 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_pte_range mm/memory.c:1059 [inline] #6: ffff88806029a258 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_pmd_range mm/memory.c:1187 [inline] #6: ffff88806029a258 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_pud_range mm/memory.c:1224 [inline] #6: ffff88806029a258 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_p4d_range mm/memory.c:1248 [inline] #6: ffff88806029a258 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_page_range+0x108a/0x4240 mm/memory.c:1346 #7: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #7: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #7: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: page_ext_get+0x20/0x2a0 mm/page_ext.c:508 #8: ffffc90000a08c00 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x600 kernel/time/timer.c:1789 #9: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #9: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #9: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hsr_announce+0xa3/0x370 net/hsr/hsr_device.c:387 #10: ffff88807c4feda0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #10: ffff88807c4feda0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: send_hsr_supervision_frame+0x276/0xad0 net/hsr/hsr_device.c:310 #11: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #11: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #11: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hsr_forward_skb+0xae/0x2400 net/hsr/hsr_forward.c:614 #12: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #12: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline] #12: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260 #13: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #13: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #13: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: br_dev_xmit+0x1b9/0x1a10 net/bridge/br_device.c:44 #14: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #14: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline] #14: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260 stack backtrace: CPU: 1 PID: 5099 Comm: syz-executor.3 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 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_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] hsr_dev_xmit+0x13e/0x1d0 net/hsr/hsr_device.c:229 __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+0x26c/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+0x3a9/0x460 include/linux/netfilter.h:314 br_forward_finish+0xe5/0x140 net/bridge/br_forward.c:66 NF_HOOK+0x3a9/0x460 include/linux/netfilter.h:314 __br_forward+0x489/0x660 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xb3/0x150 net/bridge/br_forward.c:190 br_flood+0x2e4/0x660 net/bridge/br_forward.c:236 br_dev_xmit+0x118c/0x1a10 __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+0x26c/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] hsr_xmit net/hsr/hsr_forward.c:380 [inline] hsr_forward_do net/hsr/hsr_forward.c:471 [inline] hsr_forward_skb+0x183f/0x2400 net/hsr/hsr_forward.c:619 send_hsr_supervision_frame+0x548/0xad0 net/hsr/hsr_device.c:333 hsr_announce+0x1ab/0x370 net/hsr/hsr_device.c:389 call_timer_fn+0x180/0x600 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+0x2be/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:rcu_is_watching+0x72/0xb0 kernel/rcu/tree.c:702 Code: 7d 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 22 8b 03 65 ff 0d 21 66 88 7e 74 10 83 e0 04 c1 e8 02 5b 41 5e <41> 5f e9 e7 e1 03 0a e8 f2 20 85 ff eb e9 89 d9 80 e1 07 80 c1 03 RSP: 0018:ffffc900046c72b0 EFLAGS: 00000212 RAX: 0000000000000001 RBX: ffffea0001a681c0 RCX: ffff88805f62bc00 RDX: ffff88805f62bc00 RSI: ffffffff8bfed2e0 RDI: ffffffff8bfed2a0 RBP: 0000000000000001 R08: ffffffff8203ecb1 R09: 1ffffffff259caa0 R10: dffffc0000000000 R11: fffffbfff259caa1 R12: 0000000000000000 R13: 0000000000000001 R14: ffffffff8203ec80 R15: dffffc0000000000 rcu_read_lock include/linux/rcupdate.h:751 [inline] page_ext_get+0x5a/0x2a0 mm/page_ext.c:508 page_table_check_set+0x5d/0x700 mm/page_table_check.c:109 __page_table_check_ptes_set+0x220/0x280 mm/page_table_check.c:196 page_table_check_ptes_set include/linux/page_table_check.h:74 [inline] set_ptes include/linux/pgtable.h:241 [inline] copy_present_pte mm/memory.c:993 [inline] copy_pte_range mm/memory.c:1102 [inline] copy_pmd_range mm/memory.c:1187 [inline] copy_pud_range mm/memory.c:1224 [inline] copy_p4d_range mm/memory.c:1248 [inline] copy_page_range+0x2c7f/0x4240 mm/memory.c:1346 dup_mmap kernel/fork.c:747 [inline] dup_mm kernel/fork.c:1687 [inline] copy_mm+0x12f5/0x21b0 kernel/fork.c:1736 copy_process+0x187a/0x3df0 kernel/fork.c:2389 kernel_clone+0x21e/0x8d0 kernel/fork.c:2796 __do_sys_clone kernel/fork.c:2939 [inline] __se_sys_clone kernel/fork.c:2923 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2923 do_syscall_64+0xfd/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f8d48e7add3 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffd23e8b248 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8d48e7add3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000555576c32750 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001 vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 03 00 add (%rax),%eax 2: 49 03 1e add (%r14),%rbx 5: 48 89 d8 mov %rbx,%rax 8: 48 c1 e8 03 shr $0x3,%rax c: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax 11: 84 c0 test %al,%al 13: 75 22 jne 0x37 15: 8b 03 mov (%rbx),%eax 17: 65 ff 0d 21 66 88 7e decl %gs:0x7e886621(%rip) # 0x7e88663f 1e: 74 10 je 0x30 20: 83 e0 04 and $0x4,%eax 23: c1 e8 02 shr $0x2,%eax 26: 5b pop %rbx 27: 41 5e pop %r14 * 29: 41 5f pop %r15 <-- trapping instruction 2b: e9 e7 e1 03 0a jmp 0xa03e217 30: e8 f2 20 85 ff call 0xff852127 35: eb e9 jmp 0x20 37: 89 d9 mov %ebx,%ecx 39: 80 e1 07 and $0x7,%cl 3c: 80 c1 03 add $0x3,%cl