================================================================== BUG: KASAN: use-after-free in inet_twsk_kill+0x358/0x3c0 net/ipv4/inet_timewait_sock.c:46 Read of size 8 at addr ffff8880522384c0 by task swapper/0/0 CPU: 0 PID: 0 Comm: swapper/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:finish_task_switch.isra.0+0x323/0xb80 kernel/sched/core.c:4866 Code: d3 cc fb 07 85 c0 75 02 0f 0b 48 85 db 0f 85 25 01 00 00 4c 89 f7 e8 fc f7 ff ff e8 e7 7e 2d 00 fb 65 48 8b 1c 25 00 70 02 00 <48> 8d bb 80 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffffff8b807cb0 EFLAGS: 00000202 RAX: 00000000001987d3 RBX: ffffffff8b8bc6c0 RCX: 1ffffffff1b28941 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffffff8b807cf8 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817e98b8 R11: 0000000000000001 R12: ffff8880b9c3a958 R13: ffff8880778c1d00 R14: ffff8880b9c39c00 R15: ffff8880b9c3a638 context_switch kernel/sched/core.c:4989 [inline] __schedule+0xaba/0x4e90 kernel/sched/core.c:6296 schedule_idle+0x57/0x90 kernel/sched/core.c:6397 do_idle+0x303/0x590 kernel/sched/idle.c:334 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_kernel+0x47a/0x49b init/main.c:1135 secondary_startup_64_no_verify+0xc3/0xcb Allocated by task 6453: 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 The buggy address belongs to the object at ffff888052238000 which belongs to the cache net_namespace of size 6528 The buggy address is located 1216 bytes inside of 6528-byte region [ffff888052238000, ffff888052239980) The buggy address belongs to the page: page:ffffea0001488e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88805223cf80 pfn:0x52238 head:ffffea0001488e00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88801a1f4701 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea000136cc00 dead000000000002 ffff888015385000 raw: ffff88805223cf80 0000000080040000 00000001ffffffff ffff88801a1f4701 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 3634, ts 120977370628, free_ts 11438773712 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 free_contig_range+0xa8/0xf0 mm/page_alloc.c:9335 destroy_args+0xa8/0x646 mm/debug_vm_pgtable.c:1016 debug_vm_pgtable+0x2961/0x29f3 mm/debug_vm_pgtable.c:1330 do_one_initcall+0x103/0x650 init/main.c:1297 do_initcall_level init/main.c:1370 [inline] do_initcalls init/main.c:1386 [inline] do_basic_setup init/main.c:1405 [inline] kernel_init_freeable+0x6b1/0x73a init/main.c:1610 kernel_init+0x1a/0x1d0 init/main.c:1499 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Memory state around the buggy address: ffff888052238380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888052238400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888052238480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888052238500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888052238580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 4 bytes skipped: 0: 85 c0 test %eax,%eax 2: 75 02 jne 0x6 4: 0f 0b ud2 6: 48 85 db test %rbx,%rbx 9: 0f 85 25 01 00 00 jne 0x134 f: 4c 89 f7 mov %r14,%rdi 12: e8 fc f7 ff ff callq 0xfffff813 17: e8 e7 7e 2d 00 callq 0x2d7f03 1c: fb sti 1d: 65 48 8b 1c 25 00 70 mov %gs:0x27000,%rbx 24: 02 00 * 26: 48 8d bb 80 15 00 00 lea 0x1580(%rbx),%rdi <-- trapping instruction 2d: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 34: fc ff df 37: 48 89 fa mov %rdi,%rdx 3a: 48 rex.W 3b: c1 .byte 0xc1