================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 Read of size 8 at addr ffff88802334d118 by task kworker/u4:12/8316 CPU: 0 PID: 8316 Comm: kworker/u4:12 Not tainted 5.15.110-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 tcp_retransmit_timer+0x6ee/0x2890 net/ipv4/tcp_timer.c:515 tcp_write_timer_handler+0x1f7/0x9c0 net/ipv4/tcp_timer.c:626 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:646 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1737 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1750 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:193 Code: 1f 84 00 00 00 00 00 0f 1f 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 28 c6 63 0c 48 89 de 5b e9 17 83 48 00 cc cc cc cc cc cc cc <48> 8b 04 24 65 48 8b 0d 34 91 82 7e 65 8b 15 35 91 82 7e f7 c2 00 RSP: 0018:ffffc9000492fa50 EFLAGS: 00000293 RAX: ffffffff88bb35b5 RBX: 0000000000000001 RCX: ffff888077a20000 RDX: 0000000000000000 RSI: ffffffff8ad858a0 RDI: ffffffff8ad85860 RBP: ffffc9000492fb70 R08: ffffffff88bb3411 R09: fffffbfff1f78c21 R10: 0000000000000000 R11: dffffc0000000001 R12: 00000000000428c9 R13: 1ffffffff1b773f4 R14: ffffffff917bb2c0 R15: dffffc0000000000 rcu_lock_release+0xa/0x20 include/linux/rcupdate.h:274 rcu_read_unlock include/linux/rcupdate.h:729 [inline] inet_twsk_purge+0x979/0xa20 net/ipv4/inet_timewait_sock.c:299 ops_exit_list net/core/net_namespace.c:174 [inline] cleanup_net+0x763/0xb60 net/core/net_namespace.c:596 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2306 worker_thread+0xaca/0x1280 kernel/workqueue.c:2453 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 9941: 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+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 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+0x143/0x5d0 net/core/net_namespace.c:460 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226 ksys_unshare+0x580/0xb20 kernel/fork.c:3094 __do_sys_unshare kernel/fork.c:3168 [inline] __se_sys_unshare kernel/fork.c:3166 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3166 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff88802334cec0 which belongs to the cache net_namespace of size 6464 The buggy address is located 600 bytes inside of 6464-byte region [ffff88802334cec0, ffff88802334e800) The buggy address belongs to the page: page:ffffea00008cd200 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802334cec0 pfn:0x23348 head:ffffea00008cd200 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88801de61fc1 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff888011dc7288 ffffea0001e1b808 ffff888011dc63c0 raw: ffff88802334cec0 0000000000040000 00000001ffffffff ffff88801de61fc1 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4538, ts 161895544248, free_ts 161856196956 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5421 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x18e/0x280 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+0x143/0x5d0 net/core/net_namespace.c:460 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 copy_namespaces+0x365/0x3b0 kernel/nsproxy.c:178 copy_process+0x1841/0x3ef0 kernel/fork.c:2201 kernel_clone+0x210/0x960 kernel/fork.c:2601 __do_sys_clone kernel/fork.c:2718 [inline] __se_sys_clone kernel/fork.c:2702 [inline] __x64_sys_clone+0x23f/0x290 kernel/fork.c:2702 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396 free_slab mm/slub.c:2015 [inline] discard_slab mm/slub.c:2021 [inline] __unfreeze_partials+0x1b7/0x210 mm/slub.c:2507 put_cpu_partial+0x132/0x1a0 mm/slub.c:2587 do_slab_free mm/slub.c:3487 [inline] ___cache_free+0xe3/0x100 mm/slub.c:3506 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] kmem_cache_alloc_node+0x121/0x2c0 mm/slub.c:3256 __alloc_skb+0xdd/0x590 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1167 [inline] nlmsg_new include/net/netlink.h:953 [inline] inet_netconf_notify_devconf+0x156/0x210 net/ipv4/devinet.c:2094 __devinet_sysctl_unregister net/ipv4/devinet.c:2604 [inline] devinet_sysctl_unregister net/ipv4/devinet.c:2628 [inline] inetdev_destroy net/ipv4/devinet.c:324 [inline] inetdev_event+0x7ef/0x1490 net/ipv4/devinet.c:1598 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:391 call_netdevice_notifiers_info net/core/dev.c:1998 [inline] call_netdevice_notifiers_extack net/core/dev.c:2010 [inline] call_netdevice_notifiers net/core/dev.c:2024 [inline] unregister_netdevice_many+0xf1b/0x18f0 net/core/dev.c:11065 ip_tunnel_delete_nets+0x2ed/0x330 net/ipv4/ip_tunnel.c:1123 Memory state around the buggy address: ffff88802334d000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802334d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802334d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802334d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802334d200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 84 00 test %al,(%rax) 2: 00 00 add %al,(%rax) 4: 00 00 add %al,(%rax) 6: 0f 1f 00 nopl (%rax) 9: 53 push %rbx a: 48 89 fb mov %rdi,%rbx d: e8 17 00 00 00 callq 0x29 12: 48 8b 3d 28 c6 63 0c mov 0xc63c628(%rip),%rdi # 0xc63c641 19: 48 89 de mov %rbx,%rsi 1c: 5b pop %rbx 1d: e9 17 83 48 00 jmpq 0x488339 22: cc int3 23: cc int3 24: cc int3 25: cc int3 26: cc int3 27: cc int3 28: cc int3 * 29: 48 8b 04 24 mov (%rsp),%rax <-- trapping instruction 2d: 65 48 8b 0d 34 91 82 mov %gs:0x7e829134(%rip),%rcx # 0x7e829169 34: 7e 35: 65 8b 15 35 91 82 7e mov %gs:0x7e829135(%rip),%edx # 0x7e829171 3c: f7 .byte 0xf7 3d: c2 .byte 0xc2