================================================================== 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+0x882/0x9c0 net/ipv4/tcp_timer.c:648 Read of size 1 at addr ffff888074dc068d by task kworker/u4:14/31651 CPU: 0 PID: 31651 Comm: kworker/u4:14 Not tainted 5.15.153-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: gid-cache-wq netdevice_event_work_handler 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_probe_timer net/ipv4/tcp_timer.c:384 [inline] tcp_write_timer_handler+0x882/0x9c0 net/ipv4/tcp_timer.c:648 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:664 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:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:finish_lock_switch+0x91/0x100 kernel/sched/core.c:4785 Code: 45 31 c9 68 b7 70 59 81 e8 7c 1a 09 00 48 83 c4 08 4c 89 ff e8 60 da fe ff 66 90 4c 89 ff e8 16 04 cc 08 e8 a1 46 2d 00 fb 5b <41> 5c 41 5d 41 5e 41 5f c3 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 87 RSP: 0018:ffffc90003b378d8 EFLAGS: 00000286 RAX: 5a199689957f4f00 RBX: ffff88801d301df4 RCX: ffffffff913c7f03 RDX: dffffc0000000000 RSI: ffffffff8a8b1500 RDI: ffffffff8ad88fc0 RBP: ffffc90003b37950 R08: ffffffff8186b7c0 R09: ffffed1017347461 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 1ffff1101734760b R14: ffff8880b9a3b058 R15: ffff8880b9a3a300 finish_task_switch+0x134/0x630 kernel/sched/core.c:4902 context_switch kernel/sched/core.c:5033 [inline] __schedule+0x12cc/0x45b0 kernel/sched/core.c:6376 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6552 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6577 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock_irq+0x3c/0x40 kernel/locking/spinlock.c:202 process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 26544: 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:3101 __do_sys_unshare kernel/fork.c:3175 [inline] __se_sys_unshare kernel/fork.c:3173 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3173 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 Freed by task 3604: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0x91/0x1f0 mm/slub.c:3515 net_free net/core/net_namespace.c:434 [inline] cleanup_net+0xab5/0xb60 net/core/net_namespace.c:617 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 The buggy address belongs to the object at ffff888074dc0000 which belongs to the cache net_namespace of size 6464 The buggy address is located 1677 bytes inside of 6464-byte region [ffff888074dc0000, ffff888074dc1940) The buggy address belongs to the page: page:ffffea0001d37000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x74dc0 head:ffffea0001d37000 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88801e4ea001 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888011dea3c0 raw: 0000000000000000 0000000000040004 00000001ffffffff ffff88801e4ea001 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3516, ts 54980210816, free_ts 54978512726 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 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226 ksys_unshare+0x580/0xb20 kernel/fork.c:3101 __do_sys_unshare kernel/fork.c:3175 [inline] __se_sys_unshare kernel/fork.c:3173 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3173 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 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] rtmsg_ifa+0x1e7/0x3a0 net/ipv4/devinet.c:1913 __inet_insert_ifa+0x9e4/0xc10 net/ipv4/devinet.c:552 inet_rtm_newaddr+0x8ca/0x1840 net/ipv4/devinet.c:956 rtnetlink_rcv_msg+0x993/0xee0 net/core/rtnetlink.c:5629 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2505 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1356 netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1924 Memory state around the buggy address: ffff888074dc0580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888074dc0600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888074dc0680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888074dc0700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888074dc0780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 45 31 c9 xor %r9d,%r9d 3: 68 b7 70 59 81 push $0xffffffff815970b7 8: e8 7c 1a 09 00 call 0x91a89 d: 48 83 c4 08 add $0x8,%rsp 11: 4c 89 ff mov %r15,%rdi 14: e8 60 da fe ff call 0xfffeda79 19: 66 90 xchg %ax,%ax 1b: 4c 89 ff mov %r15,%rdi 1e: e8 16 04 cc 08 call 0x8cc0439 23: e8 a1 46 2d 00 call 0x2d46c9 28: fb sti 29: 5b pop %rbx * 2a: 41 5c pop %r12 <-- trapping instruction 2c: 41 5d pop %r13 2e: 41 5e pop %r14 30: 41 5f pop %r15 32: c3 ret 33: 44 89 f1 mov %r14d,%ecx 36: 80 e1 07 and $0x7,%cl 39: 80 c1 03 add $0x3,%cl 3c: 38 c1 cmp %al,%cl 3e: 7c 87 jl 0xffffffc7