================================================================== BUG: KASAN: use-after-free in inet_twsk_kill+0x358/0x3c0 net/ipv4/inet_timewait_sock.c:46 Read of size 8 at addr ffff888050e0b9c0 by task syz-executor.0/13682 CPU: 0 PID: 13682 Comm: syz-executor.0 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x336 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 inet_twsk_kill+0x358/0x3c0 net/ipv4/inet_timewait_sock.c:46 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x67c/0xa30 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:200 Code: 81 e1 00 01 00 00 65 48 8b 14 25 00 70 02 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 a4 15 00 00 85 c0 74 2b 8b 82 80 15 00 00 <83> f8 02 75 20 48 8b 8a 88 15 00 00 8b 92 84 15 00 00 48 8b 01 48 RSP: 0000:ffffc9000349f710 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffea0001ef9500 RCX: 0000000000000000 RDX: ffff88807bde9d00 RSI: ffffffff81b2f84b RDI: 0000000000000003 RBP: ffffea0001ef9500 R08: 0000000000000000 R09: ffffea0001ef9507 R10: ffffffff81b2f835 R11: 0000000000000000 R12: ffffea0001ef9508 R13: 0000000000000000 R14: 0000000000000000 R15: 00007f92a031b000 folio_test_anon include/linux/page-flags.h:582 [inline] PageAnon include/linux/page-flags.h:587 [inline] page_remove_rmap+0x6b/0x1480 mm/rmap.c:1379 zap_pte_range mm/memory.c:1380 [inline] zap_pmd_range mm/memory.c:1490 [inline] zap_pud_range mm/memory.c:1519 [inline] zap_p4d_range mm/memory.c:1540 [inline] unmap_page_range+0xf7f/0x2a30 mm/memory.c:1561 unmap_single_vma+0x198/0x310 mm/memory.c:1606 unmap_vmas+0x16b/0x2f0 mm/memory.c:1638 exit_mmap+0x201/0x670 mm/mmap.c:3178 __mmput+0x122/0x4b0 kernel/fork.c:1114 mmput+0x56/0x60 kernel/fork.c:1135 exit_mm kernel/exit.c:507 [inline] do_exit+0xa3c/0x2a30 kernel/exit.c:793 do_group_exit+0xd2/0x2f0 kernel/exit.c:935 get_signal+0x4b0/0x28c0 kernel/signal.c:2862 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f92a04fa059 Code: Unable to access opcode bytes at RIP 0x7f92a04fa02f. RSP: 002b:00007f929ee2d168 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: fffffffffffffe00 RBX: 00007f92a060d100 RCX: 00007f92a04fa059 RDX: 0000000000000003 RSI: 0000000020003880 RDI: 0000000000000003 RBP: 00007f92a055408d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000012000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd60e1b00f R14: 00007f929ee2d300 R15: 0000000000022000 Allocated by task 13465: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:437 [inline] __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:470 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc_node mm/slub.c:3230 [inline] slab_alloc mm/slub.c:3238 [inline] kmem_cache_alloc+0x202/0x3a0 mm/slub.c:3243 kmem_cache_zalloc include/linux/slab.h:705 [inline] net_alloc net/core/net_namespace.c:407 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:462 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:3048 __do_sys_unshare kernel/fork.c:3119 [inline] __se_sys_unshare kernel/fork.c:3117 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3117 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+0x44/0xae Freed by task 13465: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:367 [inline] ____kasan_slab_free+0x130/0x160 mm/kasan/common.c:329 kasan_slab_free include/linux/kasan.h:236 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754 slab_free mm/slub.c:3509 [inline] kmem_cache_free+0xd8/0x340 mm/slub.c:3526 net_free net/core/net_namespace.c:436 [inline] net_free net/core/net_namespace.c:432 [inline] copy_net_ns+0x590/0x760 net/core/net_namespace.c:485 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:3048 __do_sys_unshare kernel/fork.c:3119 [inline] __se_sys_unshare kernel/fork.c:3117 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3117 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+0x44/0xae The buggy address belongs to the object at ffff888050e0b500 which belongs to the cache net_namespace of size 6528 The buggy address is located 1216 bytes inside of 6528-byte region [ffff888050e0b500, ffff888050e0ce80) The buggy address belongs to the page: page:ffffea0001438200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x50e08 head:ffffea0001438200 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff8880476dd941 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001d09800 dead000000000002 ffff8880159ca000 raw: 0000000000000000 0000000000040004 00000001ffffffff ffff8880476dd941 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 25147, ts 556923594068, free_ts 556566108607 prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2271 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab mm/slub.c:1944 [inline] new_slab+0x28a/0x3b0 mm/slub.c:2004 ___slab_alloc+0x87c/0xe90 mm/slub.c:3018 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3105 slab_alloc_node mm/slub.c:3196 [inline] slab_alloc mm/slub.c:3238 [inline] kmem_cache_alloc+0x35c/0x3a0 mm/slub.c:3243 kmem_cache_zalloc include/linux/slab.h:705 [inline] net_alloc net/core/net_namespace.c:407 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:462 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:3048 __do_sys_unshare kernel/fork.c:3119 [inline] __se_sys_unshare kernel/fork.c:3117 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3117 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+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1352 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1404 free_unref_page_prepare mm/page_alloc.c:3325 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3404 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x6d/0x160 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:447 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc_node mm/slub.c:3230 [inline] slab_alloc mm/slub.c:3238 [inline] kmem_cache_alloc+0x202/0x3a0 mm/slub.c:3243 anon_vma_chain_alloc mm/rmap.c:137 [inline] anon_vma_fork+0x1df/0x630 mm/rmap.c:358 dup_mmap kernel/fork.c:571 [inline] dup_mm+0xa07/0x13e0 kernel/fork.c:1451 copy_mm kernel/fork.c:1503 [inline] copy_process+0x71f8/0x7300 kernel/fork.c:2164 kernel_clone+0xe7/0xab0 kernel/fork.c:2555 __do_sys_clone+0xc8/0x110 kernel/fork.c:2672 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+0x44/0xae Memory state around the buggy address: ffff888050e0b880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888050e0b900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888050e0b980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888050e0ba00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888050e0ba80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 81 e1 00 01 00 00 and $0x100,%ecx 6: 65 48 8b 14 25 00 70 mov %gs:0x27000,%rdx d: 02 00 f: a9 00 01 ff 00 test $0xff0100,%eax 14: 74 0e je 0x24 16: 85 c9 test %ecx,%ecx 18: 74 35 je 0x4f 1a: 8b 82 a4 15 00 00 mov 0x15a4(%rdx),%eax 20: 85 c0 test %eax,%eax 22: 74 2b je 0x4f 24: 8b 82 80 15 00 00 mov 0x1580(%rdx),%eax * 2a: 83 f8 02 cmp $0x2,%eax <-- trapping instruction 2d: 75 20 jne 0x4f 2f: 48 8b 8a 88 15 00 00 mov 0x1588(%rdx),%rcx 36: 8b 92 84 15 00 00 mov 0x1584(%rdx),%edx 3c: 48 8b 01 mov (%rcx),%rax 3f: 48 rex.W