------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 4178 at lib/refcount.c:25 refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 4178 Comm: udevd Not tainted 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 lr : refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 sp : ffff800008007800 x29: ffff800008007800 x28: ffff0000e738ac00 x27: ffff0000c9981c00 x26: 1fffe0001b3b8001 x25: dfff800000000000 x24: 1fffe00019330381 x23: ffff0000ebc13000 x22: ffff0000d9409bd4 x21: ffff0000d5b0a080 x20: ffff0000d9409bd4 x19: ffff80001659e000 x18: 0000000000000101 x17: 0000000000000000 x16: ffff8000111a97c4 x15: 00000000ffffffff x14: 0000000000ff0100 x13: 0000000000000001 x12: 0000000000ff0100 x11: 0000000000000100 x10: 0000000000000000 x9 : 839fce140c89c800 x8 : 839fce140c89c800 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff8000080070f8 x4 : ffff80001423f280 x3 : ffff800008503958 x2 : 0000000000000001 x1 : 0000000000000100 x0 : 000000000000002a Call trace: refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 __refcount_add include/linux/refcount.h:-1 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] get_net include/net/net_namespace.h:252 [inline] tipc_aead_encrypt net/tipc/crypto.c:832 [inline] tipc_crypto_xmit+0x1634/0x2220 net/tipc/crypto.c:1772 tipc_bearer_xmit_skb+0x1f0/0x384 net/tipc/bearer.c:574 tipc_disc_timeout+0x4c8/0x608 net/tipc/discover.c:338 call_timer_fn+0x19c/0x858 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x46c/0x6c4 kernel/time/timer.c:1767 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1780 handle_softirqs+0x344/0xbf0 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] invoke_softirq kernel/softirq.c:457 [inline] __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659 irq_exit+0x14/0x88 kernel/softirq.c:683 handle_domain_irq+0x14c/0x1fc kernel/irq/irqdesc.c:711 gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:765 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:899 do_interrupt_handler+0x6c/0x88 arch/arm64/kernel/entry-common.c:267 el1_interrupt+0x30/0x58 arch/arm64/kernel/entry-common.c:454 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline] __call_rcu kernel/rcu/tree.c:3041 [inline] call_rcu+0x57c/0x8f0 kernel/rcu/tree.c:3087 dentry_free+0xa4/0x180 fs/dcache.c:-1 __dentry_kill+0x45c/0x598 fs/dcache.c:600 dentry_kill+0xc8/0x248 fs/dcache.c:-1 dput+0x23c/0x458 fs/dcache.c:893 do_rmdir+0x24c/0x634 fs/namei.c:4212 __do_sys_unlinkat fs/namei.c:4390 [inline] __se_sys_unlinkat fs/namei.c:4384 [inline] __arm64_sys_unlinkat+0xcc/0xfc fs/namei.c:4384 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 irq event stamp: 2810461 hardirqs last enabled at (2810460): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:257 hardirqs last disabled at (2810461): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:396 softirqs last enabled at (2810328): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:31 softirqs last disabled at (2810379): [] __do_softirq kernel/softirq.c:610 [inline] softirqs last disabled at (2810379): [] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] softirqs last disabled at (2810379): [] invoke_softirq kernel/softirq.c:457 [inline] softirqs last disabled at (2810379): [] __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659 ---[ end trace 6f2af467aed01f4a ]--- vkms_vblank_simulate: vblank timer overrun ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 4178 at lib/refcount.c:28 refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 Modules linked in: CPU: 0 PID: 4178 Comm: udevd Tainted: G W 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 lr : refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 sp : ffff800008007800 x29: ffff800008007800 x28: ffff0000e738ac00 x27: 0000000000000000 x26: 1fffe0001b3b8001 x25: dfff800000000000 x24: 1fffe00019330381 x23: ffff0000db064638 x22: ffff0000d9409a80 x21: ffff0000d5b0a080 x20: ffff0000d9409bd4 x19: ffff80001659e000 x18: 0000000000000101 x17: 0000000000000000 x16: ffff8000083008fc x15: 00000000ffffffff x14: 0000000000ff0100 x13: 0000000000000001 x12: 0000000000ff0100 x11: 0000000000000100 x10: 0000000000000000 x9 : 839fce140c89c800 x8 : 839fce140c89c800 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff8000080070f8 x4 : ffff80001423f280 x3 : ffff800008300a0c x2 : 0000000000000001 x1 : 0000000000000100 x0 : 0000000000000026 Call trace: refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] put_net include/net/net_namespace.h:270 [inline] tipc_aead_encrypt net/tipc/crypto.c:840 [inline] tipc_crypto_xmit+0x177c/0x2220 net/tipc/crypto.c:1772 tipc_bearer_xmit_skb+0x1f0/0x384 net/tipc/bearer.c:574 tipc_disc_timeout+0x4c8/0x608 net/tipc/discover.c:338 call_timer_fn+0x19c/0x858 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x46c/0x6c4 kernel/time/timer.c:1767 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1780 handle_softirqs+0x344/0xbf0 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] invoke_softirq kernel/softirq.c:457 [inline] __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659 irq_exit+0x14/0x88 kernel/softirq.c:683 handle_domain_irq+0x14c/0x1fc kernel/irq/irqdesc.c:711 gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:765 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:899 do_interrupt_handler+0x6c/0x88 arch/arm64/kernel/entry-common.c:267 el1_interrupt+0x30/0x58 arch/arm64/kernel/entry-common.c:454 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline] __call_rcu kernel/rcu/tree.c:3041 [inline] call_rcu+0x57c/0x8f0 kernel/rcu/tree.c:3087 dentry_free+0xa4/0x180 fs/dcache.c:-1 __dentry_kill+0x45c/0x598 fs/dcache.c:600 dentry_kill+0xc8/0x248 fs/dcache.c:-1 dput+0x23c/0x458 fs/dcache.c:893 do_rmdir+0x24c/0x634 fs/namei.c:4212 __do_sys_unlinkat fs/namei.c:4390 [inline] __se_sys_unlinkat fs/namei.c:4384 [inline] __arm64_sys_unlinkat+0xcc/0xfc fs/namei.c:4384 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 irq event stamp: 2810493 hardirqs last enabled at (2810492): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:257 hardirqs last disabled at (2810493): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:396 softirqs last enabled at (2810328): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:31 softirqs last disabled at (2810379): [] __do_softirq kernel/softirq.c:610 [inline] softirqs last disabled at (2810379): [] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] softirqs last disabled at (2810379): [] invoke_softirq kernel/softirq.c:457 [inline] softirqs last disabled at (2810379): [] __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659 ---[ end trace 6f2af467aed01f4b ]--- vkms_vblank_simulate: vblank timer overrun ------------[ cut here ]------------ refcount_t: saturated; leaking memory. WARNING: CPU: 0 PID: 0 at lib/refcount.c:22 refcount_warn_saturate+0x1b4/0x1f8 lib/refcount.c:22 Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : refcount_warn_saturate+0x1b4/0x1f8 lib/refcount.c:22 lr : refcount_warn_saturate+0x1b4/0x1f8 lib/refcount.c:22 sp : ffff800008007800 x29: ffff800008007800 x28: ffff0000e746b800 x27: ffff0000c9981c00 x26: 1ffff00002830711 x25: dfff800000000000 x24: 1fffe00019330381 x23: ffff0000ebc13000 x22: ffff0000d9409bd4 x21: 000000007ffffffe x20: ffff0000d9409bd4 x19: ffff80001659e000 x18: 0000000000000102 x17: 0000000000000000 x16: ffff8000083008fc x15: 00000000ffffffff x14: 0000000000ff0100 x13: 0000000000000001 x12: 0000000000ff0100 x11: 0000000000000101 x10: 0000000000000000 x9 : 3ed988a632c98c00 x8 : 3ed988a632c98c00 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff8000080070f8 x4 : ffff80001423f280 x3 : ffff800008300a0c x2 : 0000000000000001 x1 : 0000000000000101 x0 : 0000000000000026 Call trace: refcount_warn_saturate+0x1b4/0x1f8 lib/refcount.c:22 __refcount_add include/linux/refcount.h:-1 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] get_net include/net/net_namespace.h:252 [inline] tipc_aead_encrypt net/tipc/crypto.c:832 [inline] tipc_crypto_xmit+0x1634/0x2220 net/tipc/crypto.c:1772 tipc_bearer_xmit_skb+0x1f0/0x384 net/tipc/bearer.c:574 tipc_disc_timeout+0x4c8/0x608 net/tipc/discover.c:338 call_timer_fn+0x19c/0x858 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x46c/0x6c4 kernel/time/timer.c:1767 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1780 handle_softirqs+0x344/0xbf0 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] invoke_softirq kernel/softirq.c:457 [inline] __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659 irq_exit+0x14/0x88 kernel/softirq.c:683 handle_domain_irq+0x14c/0x1fc kernel/irq/irqdesc.c:711 gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:765 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:899 do_interrupt_handler+0x6c/0x88 arch/arm64/kernel/entry-common.c:267 el1_interrupt+0x30/0x58 arch/arm64/kernel/entry-common.c:454 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522 arch_local_irq_enable+0xc/0x18 arch/arm64/include/asm/irqflags.h:35 default_idle_call+0xcc/0x418 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x1c8/0x480 kernel/sched/idle.c:306 cpu_startup_entry+0x24/0x28 kernel/sched/idle.c:403 rest_init+0x360/0x390 init/main.c:741 arch_call_rest_init+0x14/0x20 init/main.c:893 start_kernel+0x49c/0x54c init/main.c:1140 __primary_switched+0xa8/0xb0 arch/arm64/kernel/head.S:468 irq event stamp: 139113 hardirqs last enabled at (139112): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:257 hardirqs last disabled at (139113): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:396 softirqs last enabled at (139026): [] softirq_handle_end kernel/softirq.c:419 [inline] softirqs last enabled at (139026): [] handle_softirqs+0xa4c/0xbf0 kernel/softirq.c:604 softirqs last disabled at (139087): [] __do_softirq kernel/softirq.c:610 [inline] softirqs last disabled at (139087): [] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] softirqs last disabled at (139087): [] invoke_softirq kernel/softirq.c:457 [inline] softirqs last disabled at (139087): [] __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659 ---[ end trace 6f2af467aed01f4c ]--- vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun