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BUG: KASAN: use-after-free in tcp_retransmit_timer+0x594/0x1d3c net/ipv4/tcp_timer.c:531
Read of size 8 at addr ffff0000d88436d8 by task ksoftirqd/0/14

CPU: 0 PID: 14 Comm: ksoftirqd/0 Not tainted 5.15.151-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
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_load8_noabort+0x44/0x50 mm/kasan/report_generic.c:309
 tcp_retransmit_timer+0x594/0x1d3c net/ipv4/tcp_timer.c:531
 tcp_write_timer_handler+0x1e8/0x8a8 net/ipv4/tcp_timer.c:644
 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
 run_ksoftirqd+0x68/0x258 kernel/softirq.c:921
 smpboot_thread_fn+0x4b0/0x920 kernel/smpboot.c:164
 kthread+0x37c/0x45c kernel/kthread.c:319
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

Allocated by task 4005:
 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 ffff0000d8843480
 which belongs to the cache net_namespace of size 6464
The buggy address is located 600 bytes inside of
 6464-byte region [ffff0000d8843480, ffff0000d8844dc0)
The buggy address belongs to the page:
page:000000004076a35b refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000d8843480 pfn:0x118840
head:000000004076a35b order:3 compound_mapcount:0 compound_pincount:0
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 0000000000000000 0000000100000001 ffff0000c0840000
raw: ffff0000d8843480 0000000080040003 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000d8843580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000d8843600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000d8843680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff0000d8843700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000d8843780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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