------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 4913 at lib/refcount.c:25 refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 4913 Comm: syz-executor Not tainted 6.1.141-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 : ffff8000080078c0 x29: ffff8000080078c0 x28: ffff0000f3030c00 x27: ffff0000d4250a08 x26: ffff0001026a45f0 x25: dfff800000000000 x24: 1fffe0001a84a141 x23: ffff0000d184ec00 x22: ffff0000ddfab9d4 x21: ffff0000ccfab880 x20: ffff0000ddfab9d4 x19: ffff800017a32000 x18: ffff800011a7bce0 x17: 0000000000000000 x16: ffff8000082d1c00 x15: 0000000000000000 x14: 00000000ffffffff x13: 0000000000000001 x12: 0000000000ff0100 x11: ff0080000819149c x10: 0000000000000000 x9 : f00f311edf9bf200 x8 : f00f311edf9bf200 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff800008007358 x4 : ffff800015154700 x3 : ffff8000083115f4 x2 : 0000000000000001 x1 : 0000000000000101 x0 : 0000000000000000 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:257 [inline] tipc_aead_encrypt net/tipc/crypto.c:821 [inline] tipc_crypto_xmit+0x1518/0x2014 net/tipc/crypto.c:1761 tipc_bearer_xmit_skb+0x1f0/0x384 net/tipc/bearer.c:574 tipc_disc_timeout+0x4c8/0x608 net/tipc/discover.c:338 call_timer_fn+0x1b8/0x964 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x460/0x6bc kernel/time/timer.c:1820 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1833 handle_softirqs+0x318/0xc6c kernel/softirq.c:596 __do_softirq+0x14/0x20 kernel/softirq.c:630 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:893 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:85 invoke_softirq kernel/softirq.c:477 [inline] __irq_exit_rcu+0x23c/0x43c kernel/softirq.c:679 irq_exit_rcu+0x14/0x84 kernel/softirq.c:691 __el1_irq arch/arm64/kernel/entry-common.c:472 [inline] el1_interrupt+0x38/0x54 arch/arm64/kernel/entry-common.c:486 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] _raw_spin_unlock_irqrestore+0x58/0xac kernel/locking/spinlock.c:194 debug_object_assert_init+0x1f8/0x2c8 lib/debugobjects.c:889 debug_timer_assert_init kernel/time/timer.c:792 [inline] debug_assert_init kernel/time/timer.c:837 [inline] try_to_del_timer_sync+0x4c/0x1e8 kernel/time/timer.c:1311 timer_delete_sync+0x15c/0x20c kernel/time/timer.c:1466 del_timer_sync include/linux/timer.h:198 [inline] schedule_timeout+0x188/0x2c8 kernel/time/timer.c:1966 io_schedule_timeout+0x8c/0xf4 kernel/sched/core.c:8785 do_wait_for_common+0x284/0x3e4 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common_io kernel/sched/completion.c:123 [inline] wait_for_completion_io_timeout+0x48/0x68 kernel/sched/completion.c:191 submit_bio_wait+0x150/0x204 block/bio.c:1324 blkdev_issue_flush+0xb4/0x100 block/blk-flush.c:467 ext4_sync_fs+0x3ec/0x724 fs/ext4/super.c:6275 sync_filesystem+0x1a0/0x218 fs/sync.c:66 ext4_quota_off+0xf4/0x45c fs/ext4/super.c:7097 ext4_quota_off_umount fs/ext4/super.c:1176 [inline] ext4_put_super+0xdc/0xd4c fs/ext4/super.c:1221 generic_shutdown_super+0x130/0x324 fs/super.c:501 kill_block_super+0x70/0xdc fs/super.c:1470 deactivate_locked_super+0xac/0x124 fs/super.c:332 deactivate_super+0xe8/0x108 fs/super.c:363 cleanup_mnt+0x37c/0x404 fs/namespace.c:1182 __cleanup_mnt+0x20/0x30 fs/namespace.c:1189 task_work_run+0x1ec/0x270 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x1f70/0x2b0c arch/arm64/kernel/signal.c:1137 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x138 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 irq event stamp: 786891 hardirqs last enabled at (786890): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:261 hardirqs last disabled at (786891): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405 softirqs last enabled at (786226): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32 softirqs last disabled at (786845): [] __do_softirq+0x14/0x20 kernel/softirq.c:630 ---[ end trace 0000000000000000 ]--- vkms_vblank_simulate: vblank timer overrun ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 4913 at lib/refcount.c:28 refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 Modules linked in: CPU: 0 PID: 4913 Comm: syz-executor Tainted: G W 6.1.141-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 : ffff8000080078c0 x29: ffff8000080078c0 x28: ffff0000f3030c00 x27: 0000000000000000 x26: ffff0001026a45f0 x25: dfff800000000000 x24: 1fffe000204d48c8 x23: 1fffe00019d66a69 x22: ffff0000d4250a00 x21: 00000000c0000000 x20: ffff0000ddfab9d4 x19: ffff800017a32000 x18: ffff800011a7bce0 x17: 0000000000000000 x16: ffff8000082d1c00 x15: 0000000000000000 x14: 00000000ffffffff x13: 0000000000000001 x12: 0000000000ff0100 x11: ff0080000819149c x10: 0000000000000000 x9 : f00f311edf9bf200 x8 : f00f311edf9bf200 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff800008007358 x4 : ffff800015154700 x3 : ffff80000a83c7ec x2 : ffff00019f717cd0 x1 : 0000000000000101 x0 : 0000000000000000 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:276 [inline] tipc_aead_encrypt net/tipc/crypto.c:829 [inline] tipc_crypto_xmit+0x1664/0x2014 net/tipc/crypto.c:1761 tipc_bearer_xmit_skb+0x1f0/0x384 net/tipc/bearer.c:574 tipc_disc_timeout+0x4c8/0x608 net/tipc/discover.c:338 call_timer_fn+0x1b8/0x964 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x460/0x6bc kernel/time/timer.c:1820 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1833 handle_softirqs+0x318/0xc6c kernel/softirq.c:596 __do_softirq+0x14/0x20 kernel/softirq.c:630 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:893 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:85 invoke_softirq kernel/softirq.c:477 [inline] __irq_exit_rcu+0x23c/0x43c kernel/softirq.c:679 irq_exit_rcu+0x14/0x84 kernel/softirq.c:691 __el1_irq arch/arm64/kernel/entry-common.c:472 [inline] el1_interrupt+0x38/0x54 arch/arm64/kernel/entry-common.c:486 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] _raw_spin_unlock_irqrestore+0x58/0xac kernel/locking/spinlock.c:194 debug_object_assert_init+0x1f8/0x2c8 lib/debugobjects.c:889 debug_timer_assert_init kernel/time/timer.c:792 [inline] debug_assert_init kernel/time/timer.c:837 [inline] try_to_del_timer_sync+0x4c/0x1e8 kernel/time/timer.c:1311 timer_delete_sync+0x15c/0x20c kernel/time/timer.c:1466 del_timer_sync include/linux/timer.h:198 [inline] schedule_timeout+0x188/0x2c8 kernel/time/timer.c:1966 io_schedule_timeout+0x8c/0xf4 kernel/sched/core.c:8785 do_wait_for_common+0x284/0x3e4 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common_io kernel/sched/completion.c:123 [inline] wait_for_completion_io_timeout+0x48/0x68 kernel/sched/completion.c:191 submit_bio_wait+0x150/0x204 block/bio.c:1324 blkdev_issue_flush+0xb4/0x100 block/blk-flush.c:467 ext4_sync_fs+0x3ec/0x724 fs/ext4/super.c:6275 sync_filesystem+0x1a0/0x218 fs/sync.c:66 ext4_quota_off+0xf4/0x45c fs/ext4/super.c:7097 ext4_quota_off_umount fs/ext4/super.c:1176 [inline] ext4_put_super+0xdc/0xd4c fs/ext4/super.c:1221 generic_shutdown_super+0x130/0x324 fs/super.c:501 kill_block_super+0x70/0xdc fs/super.c:1470 deactivate_locked_super+0xac/0x124 fs/super.c:332 deactivate_super+0xe8/0x108 fs/super.c:363 cleanup_mnt+0x37c/0x404 fs/namespace.c:1182 __cleanup_mnt+0x20/0x30 fs/namespace.c:1189 task_work_run+0x1ec/0x270 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x1f70/0x2b0c arch/arm64/kernel/signal.c:1137 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x138 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 irq event stamp: 786923 hardirqs last enabled at (786922): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:261 hardirqs last disabled at (786923): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405 softirqs last enabled at (786226): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32 softirqs last disabled at (786845): [] __do_softirq+0x14/0x20 kernel/softirq.c:630 ---[ end trace 0000000000000000 ]--- vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun ------------[ cut here ]------------ refcount_t: saturated; leaking memory. WARNING: CPU: 0 PID: 4309 at lib/refcount.c:22 refcount_warn_saturate+0x1b4/0x1f8 lib/refcount.c:22 Modules linked in: CPU: 0 PID: 4309 Comm: syz-executor Tainted: G W 6.1.141-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 : ffff8000080078c0 x29: ffff8000080078c0 x28: ffff0000f48bac00 x27: ffff0000d4250a08 x26: ffff0001026a45f0 x25: dfff800000000000 x24: 1fffe0001a84a141 x23: ffff0000d184ec00 x22: ffff0000ddfab9d4 x21: 000000007ffffffe x20: ffff0000ddfab9d4 x19: ffff800017a32000 x18: 0000000000000000 x17: 0000000000000000 x16: ffff8000082d1c00 x15: 0000000000000000 x14: 00000000ffffffff x13: 0000000000000001 x12: 0000000000ff0100 x11: ff0080000819149c x10: 0000000000000000 x9 : 2466aa4a48e8e000 x8 : 2466aa4a48e8e000 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff800008007358 x4 : ffff800015154700 x3 : ffff80000852da40 x2 : 0000000000000001 x1 : 0000000000000103 x0 : 0000000000000000 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:257 [inline] tipc_aead_encrypt net/tipc/crypto.c:821 [inline] tipc_crypto_xmit+0x1518/0x2014 net/tipc/crypto.c:1761 tipc_bearer_xmit_skb+0x1f0/0x384 net/tipc/bearer.c:574 tipc_disc_timeout+0x4c8/0x608 net/tipc/discover.c:338 call_timer_fn+0x1b8/0x964 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x460/0x6bc kernel/time/timer.c:1820 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1833 handle_softirqs+0x318/0xc6c kernel/softirq.c:596 __do_softirq+0x14/0x20 kernel/softirq.c:630 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:893 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:85 invoke_softirq kernel/softirq.c:477 [inline] __irq_exit_rcu+0x23c/0x43c kernel/softirq.c:679 irq_exit_rcu+0x14/0x84 kernel/softirq.c:691 __el1_irq arch/arm64/kernel/entry-common.c:472 [inline] el1_interrupt+0x38/0x54 arch/arm64/kernel/entry-common.c:486 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline] lock_acquire+0x24c/0x644 kernel/locking/lockdep.c:5665 rcu_lock_acquire+0x40/0x4c include/linux/rcupdate.h:350 rcu_read_lock_sched include/linux/rcupdate.h:883 [inline] pfn_valid+0xa4/0x3cc include/linux/mmzone.h:1857 page_table_check_set+0x3c/0x420 mm/page_table_check.c:108 __page_table_check_pte_set+0x110/0x134 mm/page_table_check.c:208 page_table_check_pte_set include/linux/page_table_check.h:83 [inline] set_pte_at arch/arm64/include/asm/pgtable.h:357 [inline] copy_present_pte mm/memory.c:1000 [inline] copy_pte_range mm/memory.c:1091 [inline] copy_pmd_range mm/memory.c:1177 [inline] copy_pud_range mm/memory.c:1214 [inline] copy_p4d_range mm/memory.c:1238 [inline] copy_page_range+0x1dec/0x292c mm/memory.c:1336 dup_mmap kernel/fork.c:697 [inline] dup_mm kernel/fork.c:1541 [inline] copy_mm+0xabc/0x11d4 kernel/fork.c:1590 copy_process+0x1618/0x3670 kernel/fork.c:2351 kernel_clone+0x1d8/0x8fc kernel/fork.c:2757 __do_sys_clone kernel/fork.c:2898 [inline] __se_sys_clone kernel/fork.c:2866 [inline] __arm64_sys_clone+0x140/0x19c kernel/fork.c:2866 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 irq event stamp: 1006955 hardirqs last enabled at (1006954): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:261 hardirqs last disabled at (1006955): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405 softirqs last enabled at (1006536): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32 softirqs last disabled at (1006927): [] __do_softirq+0x14/0x20 kernel/softirq.c:630 ---[ end trace 0000000000000000 ]--- vkms_vblank_simulate: vblank timer overrun