================================================================== BUG: KASAN: use-after-free in ip_icmp_error+0x52a/0x5a0 net/ipv4/ip_sockglue.c:404 Read of size 1 at addr ffff888093b5a7ff by task swapper/1/0 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.7.0-rc7-next-20200526-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x413 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 ip_icmp_error+0x52a/0x5a0 net/ipv4/ip_sockglue.c:404 tcp_v4_err+0x99e/0x1ce0 net/ipv4/tcp_ipv4.c:576 icmp_socket_deliver+0x1e1/0x360 net/ipv4/icmp.c:803 icmp_unreach+0x33b/0xab0 net/ipv4/icmp.c:920 icmp_rcv+0xee6/0x15f0 net/ipv4/icmp.c:1102 ip_protocol_deliver_rcu+0x57/0x880 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x220/0x360 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip_local_deliver+0x1c8/0x4e0 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:441 [inline] ip_rcv_finish+0x1da/0x2f0 net/ipv4/ip_input.c:428 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip_rcv+0xd0/0x3c0 net/ipv4/ip_input.c:539 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5268 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5382 process_backlog+0x21e/0x7a0 net/core/dev.c:6214 napi_poll net/core/dev.c:6659 [inline] net_rx_action+0x4e1/0x10d0 net/core/dev.c:6727 __do_softirq+0x268/0x9ee kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x192/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:546 [inline] smp_apic_timer_interrupt+0x19e/0x600 arch/x86/kernel/apic/apic.c:1107 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:1030 RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61 Code: cc cc cc cc cc cc cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 44 b9 4a 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 34 b9 4a 00 fb f4 cc 41 56 41 55 41 54 55 53 e8 b3 eb 82 f9 e8 5e 66 fd ff 0f 1f RSP: 0018:ffffc90000d3fc70 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffff8880a95f4340 RBX: 0000000000000000 RCX: 1ffffffff1519a2e RDX: 0000000000000000 RSI: ffffffff87ddf958 RDI: ffff8880a95f4bc8 RBP: ffff8880a6b54064 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a6b54064 R13: 1ffff920001a7f99 R14: ffff8880a6b54065 R15: 0000000000000001 arch_safe_halt arch/x86/include/asm/paravirt.h:150 [inline] acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline] acpi_safe_halt+0x8d/0x110 drivers/acpi/processor_idle.c:108 acpi_idle_do_entry+0xa9/0xe0 drivers/acpi/processor_idle.c:525 acpi_idle_enter+0x437/0xb20 drivers/acpi/processor_idle.c:651 cpuidle_enter_state+0xdb/0xd50 drivers/cpuidle/cpuidle.c:234 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:345 call_cpuidle kernel/sched/idle.c:117 [inline] cpuidle_idle_call kernel/sched/idle.c:207 [inline] do_idle+0x42f/0x690 kernel/sched/idle.c:269 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:361 start_secondary+0x2f8/0x410 arch/x86/kernel/smpboot.c:268 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242 Allocated by task 3341: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc mm/kasan/common.c:494 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:467 __kmalloc_reserve.isra.0+0x39/0xe0 net/core/skbuff.c:142 __alloc_skb+0xef/0x5a0 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1083 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:492 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:549 [inline] nsim_dev_trap_report_work+0x2bb/0xbc0 drivers/net/netdevsim/dev.c:590 process_one_work+0x965/0x1690 kernel/workqueue.c:2268 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:350 Freed by task 3341: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 skb_free_head+0x8b/0xa0 net/core/skbuff.c:590 skb_release_data+0x617/0x8a0 net/core/skbuff.c:610 skb_release_all+0x46/0x60 net/core/skbuff.c:664 __kfree_skb net/core/skbuff.c:678 [inline] consume_skb net/core/skbuff.c:837 [inline] consume_skb+0xf3/0x3f0 net/core/skbuff.c:831 nsim_dev_trap_report drivers/net/netdevsim/dev.c:565 [inline] nsim_dev_trap_report_work+0x86d/0xbc0 drivers/net/netdevsim/dev.c:590 process_one_work+0x965/0x1690 kernel/workqueue.c:2268 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:350 The buggy address belongs to the object at ffff888093b5a000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 2047 bytes inside of 4096-byte region [ffff888093b5a000, ffff888093b5b000) The buggy address belongs to the page: page:ffffea00024ed680 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 head:ffffea00024ed680 order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea00024ed608 ffffea00024c0708 ffff8880aa002000 raw: 0000000000000000 ffff888093b5a000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888093b5a680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888093b5a700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888093b5a780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888093b5a800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888093b5a880: fb fb fb fb fb fb fb fb fb fb fb 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