------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 5285 at lib/refcount.c:25 refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 Modules linked in: CPU: 1 PID: 5285 Comm: syz.2.315 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 : ffff800008017640 x29: ffff800008017640 x28: ffff0000e7a79000 x27: ffff0000d54e6a00 x26: 1fffe000182d36d1 x25: dfff800000000000 x24: 1fffe0001aa9cd41 x23: ffff0000ead70c00 x22: ffff0000c1da1bd4 x21: ffff0000da23e880 x20: ffff0000c1da1bd4 x19: ffff80001659e000 x18: 0000000000000102 x17: 0000000000000000 x16: ffff8000111a97c4 x15: 00000000ffffffff x14: 0000000000ff0100 x13: 0000000000000001 x12: 0000000000ff0100 x11: 0000000000000101 x10: 0000000000000000 x9 : dad266216bc07300 x8 : dad266216bc07300 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff800008016f38 x4 : ffff80001423f280 x3 : ffff800008503958 x2 : 0000000000000001 x1 : 0000000100000101 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_crypto_clone_msg+0x98/0x150 net/tipc/crypto.c:1667 tipc_crypto_xmit+0x17a0/0x2220 net/tipc/crypto.c:1728 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 arch/arm64/include/asm/irqflags.h:35 [inline] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0xa0/0x128 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:413 [inline] shmem_add_to_page_cache+0xcbc/0x134c mm/shmem.c:752 shmem_getpage_gfp+0x1258/0x1ef0 mm/shmem.c:1940 shmem_fault+0x170/0x430 mm/shmem.c:2118 __do_fault+0x120/0x5d0 mm/memory.c:3928 do_read_fault mm/memory.c:4264 [inline] do_fault mm/memory.c:4392 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1b4c/0x2950 mm/memory.c:4883 faultin_page mm/gup.c:976 [inline] __get_user_pages+0x3f4/0x9a4 mm/gup.c:1197 populate_vma_page_range+0x1f4/0x284 mm/gup.c:1529 __mm_populate+0x238/0x36c mm/gup.c:1638 mm_populate include/linux/mm.h:2632 [inline] vm_mmap_pgoff+0x1cc/0x284 mm/util.c:556 ksys_mmap_pgoff+0x11c/0x620 mm/mmap.c:1623 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21 __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: 3845 hardirqs last enabled at (3844): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:257 hardirqs last disabled at (3845): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:396 softirqs last enabled at (722): [] softirq_handle_end kernel/softirq.c:419 [inline] softirqs last enabled at (722): [] handle_softirqs+0xa4c/0xbf0 kernel/softirq.c:604 softirqs last disabled at (3809): [] __do_softirq kernel/softirq.c:610 [inline] softirqs last disabled at (3809): [] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] softirqs last disabled at (3809): [] invoke_softirq kernel/softirq.c:457 [inline] softirqs last disabled at (3809): [] __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659 ---[ end trace 70d254170ce32e81 ]--- ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 5285 at lib/refcount.c:28 refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 Modules linked in: CPU: 1 PID: 5285 Comm: syz.2.315 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 : ffff800008017640 x29: ffff800008017640 x28: ffff0000e7a79000 x27: 0000000000000000 x26: 1fffe000182d36d1 x25: dfff800000000000 x24: 1fffe0001aa9cd41 x23: ffff0000d352a190 x22: ffff0000c1da1a80 x21: ffff0000da23e880 x20: ffff0000c1da1bd4 x19: ffff80001659e000 x18: 0000000000000102 x17: 0000000000000000 x16: ffff8000083008fc x15: 00000000ffffffff x14: 0000000000ff0100 x13: 0000000000000001 x12: 0000000000ff0100 x11: 0000000000000101 x10: 0000000000000000 x9 : dad266216bc07300 x8 : dad266216bc07300 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff800008016f38 x4 : ffff80001423f280 x3 : ffff800008300a0c x2 : 0000000000000001 x1 : 0000000100000101 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_crypto_clone_msg+0x98/0x150 net/tipc/crypto.c:1667 tipc_crypto_xmit+0x17a0/0x2220 net/tipc/crypto.c:1728 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 arch/arm64/include/asm/irqflags.h:35 [inline] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0xa0/0x128 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:413 [inline] shmem_add_to_page_cache+0xcbc/0x134c mm/shmem.c:752 shmem_getpage_gfp+0x1258/0x1ef0 mm/shmem.c:1940 shmem_fault+0x170/0x430 mm/shmem.c:2118 __do_fault+0x120/0x5d0 mm/memory.c:3928 do_read_fault mm/memory.c:4264 [inline] do_fault mm/memory.c:4392 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1b4c/0x2950 mm/memory.c:4883 faultin_page mm/gup.c:976 [inline] __get_user_pages+0x3f4/0x9a4 mm/gup.c:1197 populate_vma_page_range+0x1f4/0x284 mm/gup.c:1529 __mm_populate+0x238/0x36c mm/gup.c:1638 mm_populate include/linux/mm.h:2632 [inline] vm_mmap_pgoff+0x1cc/0x284 mm/util.c:556 ksys_mmap_pgoff+0x11c/0x620 mm/mmap.c:1623 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21 __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: 3871 hardirqs last enabled at (3870): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:257 hardirqs last disabled at (3871): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:396 softirqs last enabled at (722): [] softirq_handle_end kernel/softirq.c:419 [inline] softirqs last enabled at (722): [] handle_softirqs+0xa4c/0xbf0 kernel/softirq.c:604 softirqs last disabled at (3809): [] __do_softirq kernel/softirq.c:610 [inline] softirqs last disabled at (3809): [] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] softirqs last disabled at (3809): [] invoke_softirq kernel/softirq.c:457 [inline] softirqs last disabled at (3809): [] __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659 ---[ end trace 70d254170ce32e83 ]---