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BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:384 [inline]
BUG: KASAN: use-after-free in tcp_write_timer_handler+0x78c/0x8a8 net/ipv4/tcp_timer.c:648
Read of size 1 at addr ffff0000db8b20cd by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.15.152-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 print_address_description+0x7c/0x3f0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x174/0x1e4 mm/kasan/report.c:451
 __asan_report_load1_noabort+0x44/0x50 mm/kasan/report_generic.c:306
 tcp_probe_timer net/ipv4/tcp_timer.c:384 [inline]
 tcp_write_timer_handler+0x78c/0x8a8 net/ipv4/tcp_timer.c:648
 tcp_write_timer+0x178/0x318 net/ipv4/tcp_timer.c:664
 call_timer_fn+0x19c/0x8f0 kernel/time/timer.c:1421
 expire_timers kernel/time/timer.c:1466 [inline]
 __run_timers+0x554/0x718 kernel/time/timer.c:1737
 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1750
 __do_softirq+0x344/0xdb0 kernel/softirq.c:558
 do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline]
 invoke_softirq kernel/softirq.c:439 [inline]
 __irq_exit_rcu+0x264/0x4d4 kernel/softirq.c:637
 irq_exit+0x14/0x88 kernel/softirq.c:661
 handle_domain_irq+0xf4/0x178 kernel/irq/irqdesc.c:710
 gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:758
 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:899
 do_interrupt_handler+0x74/0x94 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:580
 arch_local_irq_enable+0xc/0x18 arch/arm64/include/asm/irqflags.h:35
 default_idle_call+0xcc/0x4a8 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:194 [inline]
 do_idle+0x1d4/0x4dc kernel/sched/idle.c:306
 cpu_startup_entry+0x24/0x28 kernel/sched/idle.c:403
 rest_init+0x364/0x38c init/main.c:738
 arch_call_rest_init+0x14/0x20 init/main.c:890
 start_kernel+0x440/0x600 init/main.c:1137
 __primary_switched+0xa8/0xb0 arch/arm64/kernel/head.S:468

Allocated by task 3998:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x8c/0xcc mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x74/0x3f4 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x1dc/0x45c mm/slub.c:3233
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 net_alloc net/core/net_namespace.c:405 [inline]
 copy_net_ns+0x128/0x5e4 net/core/net_namespace.c:460
 create_new_namespaces+0x330/0x61c kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x108/0x158 kernel/nsproxy.c:226
 ksys_unshare+0x45c/0x874 kernel/fork.c:3101
 __do_sys_unshare kernel/fork.c:3175 [inline]
 __se_sys_unshare kernel/fork.c:3173 [inline]
 __arm64_sys_unshare+0x3c/0x50 kernel/fork.c:3173
 __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+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

The buggy address belongs to the object at ffff0000db8b1a40
 which belongs to the cache net_namespace of size 6464
The buggy address is located 1677 bytes inside of
 6464-byte region [ffff0000db8b1a40, ffff0000db8b3380)
The buggy address belongs to the page:
page:000000004ddf5816 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11b8b0
head:000000004ddf5816 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 0000000000000000 dead000000000122 ffff0000c0840000
raw: 0000000000000000 0000000080040004 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000db8b1f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000db8b2000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000db8b2080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff0000db8b2100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000db8b2180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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