================================================================== BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:378 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler net/ipv4/tcp_timer.c:624 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler+0x998/0x9f0 net/ipv4/tcp_timer.c:594 Read of size 1 at addr ffff888078e73fc5 by task swapper/1/0 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.1.0-rc1-syzkaller-00170-g3bd5549bd479 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x45d mm/kasan/report.c:395 kasan_report+0xbb/0x1f0 mm/kasan/report.c:495 tcp_probe_timer net/ipv4/tcp_timer.c:378 [inline] tcp_write_timer_handler net/ipv4/tcp_timer.c:624 [inline] tcp_write_timer_handler+0x998/0x9f0 net/ipv4/tcp_timer.c:594 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:637 call_timer_fn+0x1da/0x7c0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x6a2/0xaf0 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x1f7/0xad8 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:113 [inline] RIP: 0010:acpi_idle_do_entry+0x1fd/0x2a0 drivers/acpi/processor_idle.c:572 Code: 89 de e8 26 5a eb f7 84 db 75 ac e8 8d 5d eb f7 e8 48 d4 f1 f7 66 90 e8 81 5d eb f7 0f 00 2d 8a 6a c3 00 e8 75 5d eb f7 fb f4 <9c> 5b 81 e3 00 02 00 00 fa 31 ff 48 89 de e8 50 5a eb f7 48 85 db RSP: 0018:ffffc90000177d10 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888011aa9d40 RSI: ffffffff89912d7b RDI: ffffffff89912d68 RBP: ffff888011ace864 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: ffff888011ace800 R14: ffff888011ace864 R15: ffff88801bb71804 acpi_idle_enter+0x364/0x500 drivers/acpi/processor_idle.c:709 cpuidle_enter_state+0x1ab/0xd30 drivers/cpuidle/cpuidle.c:239 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:356 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:236 [inline] do_idle+0x3f7/0x590 kernel/sched/idle.c:303 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:400 start_secondary+0x252/0x300 arch/x86/kernel/smpboot.c:262 secondary_startup_64_no_verify+0xce/0xdb Allocated by task 3643: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x7e/0x80 mm/kasan/common.c:325 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x2ac/0x3c0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:702 [inline] net_alloc net/core/net_namespace.c:403 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:458 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3188 __do_sys_unshare kernel/fork.c:3259 [inline] __se_sys_unshare kernel/fork.c:3257 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3257 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 92: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2a/0x40 mm/kasan/generic.c:511 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] kmem_cache_free+0xea/0x5b0 mm/slub.c:3683 net_free net/core/net_namespace.c:432 [inline] net_free net/core/net_namespace.c:428 [inline] cleanup_net+0x8ba/0xb00 net/core/net_namespace.c:615 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 The buggy address belongs to the object at ffff888078e73880 which belongs to the cache net_namespace of size 6976 The buggy address is located 1861 bytes inside of 6976-byte region [ffff888078e73880, ffff888078e753c0) The buggy address belongs to the physical page: page:ffffea0001e39c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888078e754c0 pfn:0x78e70 head:ffffea0001e39c00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88801d17c001 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001d99400 dead000000000002 ffff888140006500 raw: ffff888078e754c0 0000000080040003 00000001ffffffff ffff88801d17c001 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 3641, tgid 3641 (syz-executor.1), ts 119038530041, free_ts 118786309136 prep_new_page mm/page_alloc.c:2538 [inline] get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4287 __alloc_pages+0x1c7/0x5a0 mm/page_alloc.c:5554 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2280 alloc_slab_page mm/slub.c:1794 [inline] allocate_slab+0x213/0x300 mm/slub.c:1939 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3180 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3279 slab_alloc_node mm/slub.c:3364 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x312/0x3c0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:702 [inline] net_alloc net/core/net_namespace.c:403 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:458 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3188 __do_sys_unshare kernel/fork.c:3259 [inline] __se_sys_unshare kernel/fork.c:3257 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3257 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1458 [inline] free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1508 free_unref_page_prepare mm/page_alloc.c:3386 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3482 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x62/0x80 mm/kasan/common.c:302 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3398 [inline] __kmem_cache_alloc_node+0x2da/0x3e0 mm/slub.c:3437 kmalloc_trace+0x22/0x60 mm/slab_common.c:1046 kmalloc include/linux/slab.h:576 [inline] kzalloc include/linux/slab.h:712 [inline] snmp6_alloc_dev net/ipv6/addrconf.c:349 [inline] ipv6_add_dev+0x5af/0x1320 net/ipv6/addrconf.c:403 addrconf_notify+0x6f9/0x1c10 net/ipv6/addrconf.c:3528 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1945 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline] call_netdevice_notifiers net/core/dev.c:1997 [inline] register_netdevice+0x10bb/0x1670 net/core/dev.c:10090 register_netdev+0x2d/0x50 net/core/dev.c:10183 ip6gre_init_net+0x3cd/0x630 net/ipv6/ip6_gre.c:1618 ops_init+0xaf/0x470 net/core/net_namespace.c:134 setup_net+0x5d1/0xc50 net/core/net_namespace.c:325 Memory state around the buggy address: ffff888078e73e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078e73f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888078e73f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888078e74000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078e74080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 89 de mov %ebx,%esi 2: e8 26 5a eb f7 callq 0xf7eb5a2d 7: 84 db test %bl,%bl 9: 75 ac jne 0xffffffb7 b: e8 8d 5d eb f7 callq 0xf7eb5d9d 10: e8 48 d4 f1 f7 callq 0xf7f1d45d 15: 66 90 xchg %ax,%ax 17: e8 81 5d eb f7 callq 0xf7eb5d9d 1c: 0f 00 2d 8a 6a c3 00 verw 0xc36a8a(%rip) # 0xc36aad 23: e8 75 5d eb f7 callq 0xf7eb5d9d 28: fb sti 29: f4 hlt * 2a: 9c pushfq <-- trapping instruction 2b: 5b pop %rbx 2c: 81 e3 00 02 00 00 and $0x200,%ebx 32: fa cli 33: 31 ff xor %edi,%edi 35: 48 89 de mov %rbx,%rsi 38: e8 50 5a eb f7 callq 0xf7eb5a8d 3d: 48 85 db test %rbx,%rbx