================================================================== BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2ea2/0x3320 net/ipv4/tcp_timer.c:511 Read of size 8 at addr ffff88807d990338 by task swapper/0/0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.17.0-rc6-syzkaller-00226-g07ebd38a0da2-dirty #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/0x303 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 tcp_retransmit_timer+0x2ea2/0x3320 net/ipv4/tcp_timer.c:511 tcp_write_timer_handler+0x5e6/0xbc0 net/ipv4/tcp_timer.c:622 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:642 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: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:116 [inline] RIP: 0010:acpi_idle_do_entry+0x1c6/0x250 drivers/acpi/processor_idle.c:556 Code: 89 de e8 5d 1d 29 f8 84 db 75 ac e8 f4 19 29 f8 e8 2f 58 2f f8 eb 0c e8 e8 19 29 f8 0f 00 2d 41 33 c2 00 e8 dc 19 29 f8 fb f4 <9c> 5b 81 e3 00 02 00 00 fa 31 ff 48 89 de e8 d7 1b 29 f8 48 85 db RSP: 0018:ffffffff8b807d60 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffffffff8b8bc6c0 RSI: ffffffff894ec924 RDI: 0000000000000000 RBP: ffff888012bb4864 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817e2178 R11: 0000000000000000 R12: 0000000000000001 R13: ffff888012bb4800 R14: ffff888012bb4864 R15: ffff888018f68804 acpi_idle_enter+0x361/0x500 drivers/acpi/processor_idle.c:692 cpuidle_enter_state+0x1b1/0xc80 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x3e8/0x590 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_kernel+0x47a/0x49b init/main.c:1138 secondary_startup_64_no_verify+0xc3/0xcb Allocated by task 3882: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] __kasan_slab_alloc+0x85/0xb0 mm/kasan/common.c:469 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc mm/slab.c:3315 [inline] kmem_cache_alloc+0x265/0x560 mm/slab.c:3499 kmem_cache_zalloc include/linux/slab.h:704 [inline] net_alloc net/core/net_namespace.c:406 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:461 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:3058 __do_sys_unshare kernel/fork.c:3129 [inline] __se_sys_unshare kernel/fork.c:3127 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3127 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 44: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0xff/0x140 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:236 [inline] __cache_free mm/slab.c:3437 [inline] kmem_cache_free.part.0+0x91/0x200 mm/slab.c:3733 net_free net/core/net_namespace.c:435 [inline] net_free net/core/net_namespace.c:431 [inline] cleanup_net+0x8ba/0xb00 net/core/net_namespace.c:618 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff88807d990080 which belongs to the cache net_namespace of size 6528 The buggy address is located 696 bytes inside of 6528-byte region [ffff88807d990080, ffff88807d991a00) The buggy address belongs to the page: page:ffffea0001f66400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7d990 head:ffffea0001f66400 order:1 compound_mapcount:0 memcg:ffff88807ba05541 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff8880161a9850 ffffea0001c6e488 ffff8881400a2a00 raw: 0000000000000000 ffff88807d990080 0000000100000001 ffff88807ba05541 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x3420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_HARDWALL|__GFP_THISNODE), pid 3882, ts 64369149646, free_ts 64341052408 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_node include/linux/gfp.h:572 [inline] kmem_getpages mm/slab.c:1378 [inline] cache_grow_begin+0x75/0x390 mm/slab.c:2584 cache_alloc_refill+0x27f/0x380 mm/slab.c:2957 ____cache_alloc mm/slab.c:3040 [inline] ____cache_alloc mm/slab.c:3023 [inline] __do_cache_alloc mm/slab.c:3267 [inline] slab_alloc mm/slab.c:3308 [inline] kmem_cache_alloc+0x450/0x560 mm/slab.c:3499 kmem_cache_zalloc include/linux/slab.h:704 [inline] net_alloc net/core/net_namespace.c:406 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:461 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:3058 __do_sys_unshare kernel/fork.c:3129 [inline] __se_sys_unshare kernel/fork.c:3127 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3127 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 slab_destroy mm/slab.c:1630 [inline] slabs_destroy+0x89/0xc0 mm/slab.c:1650 cache_flusharray mm/slab.c:3410 [inline] ___cache_free+0x303/0x600 mm/slab.c:3472 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x50/0x1a0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x97/0xb0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc mm/slab.c:3315 [inline] kmem_cache_alloc+0x265/0x560 mm/slab.c:3499 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags include/linux/audit.h:323 [inline] getname fs/namei.c:217 [inline] __do_sys_unlink fs/namei.c:4266 [inline] __se_sys_unlink fs/namei.c:4264 [inline] __x64_sys_unlink+0xb1/0x110 fs/namei.c:4264 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: ffff88807d990200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d990280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807d990300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807d990380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d990400: 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 5d 1d 29 f8 callq 0xf8291d64 7: 84 db test %bl,%bl 9: 75 ac jne 0xffffffb7 b: e8 f4 19 29 f8 callq 0xf8291a04 10: e8 2f 58 2f f8 callq 0xf82f5844 15: eb 0c jmp 0x23 17: e8 e8 19 29 f8 callq 0xf8291a04 1c: 0f 00 2d 41 33 c2 00 verw 0xc23341(%rip) # 0xc23364 23: e8 dc 19 29 f8 callq 0xf8291a04 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 d7 1b 29 f8 callq 0xf8291c14 3d: 48 85 db test %rbx,%rbx