================================================================== BUG: KASAN: use-after-free in packet_rcv+0x5aa/0x1490 net/packet/af_packet.c:2104 Read of size 1 at addr ffff8880a0448a6c by task syz-executor.4/21346 CPU: 0 PID: 21346 Comm: syz-executor.4 Not tainted 4.19.211-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+0x1fc/0x2ef lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load1_noabort+0x88/0x90 mm/kasan/report.c:430 packet_rcv+0x5aa/0x1490 net/packet/af_packet.c:2104 deliver_skb net/core/dev.c:1956 [inline] dev_queue_xmit_nit+0x24d/0xa20 net/core/dev.c:2012 xmit_one net/core/dev.c:3252 [inline] dev_hard_start_xmit+0xaa/0x920 net/core/dev.c:3272 __dev_queue_xmit+0x269d/0x2e00 net/core/dev.c:3838 neigh_resolve_output+0x55a/0x910 net/core/neighbour.c:1374 neigh_output include/net/neighbour.h:501 [inline] ip6_finish_output2+0x113d/0x2290 net/ipv6/ip6_output.c:120 ip6_finish_output+0x89b/0x10f0 net/ipv6/ip6_output.c:192 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x205/0x770 net/ipv6/ip6_output.c:209 dst_output include/net/dst.h:455 [inline] NF_HOOK include/linux/netfilter.h:289 [inline] ndisc_send_skb+0xa24/0x1720 net/ipv6/ndisc.c:491 ndisc_send_rs+0x131/0x690 net/ipv6/ndisc.c:685 addrconf_rs_timer+0x384/0x6a0 net/ipv6/addrconf.c:3835 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375 __run_timers kernel/time/timer.c:1696 [inline] run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1709 __do_softirq+0x265/0x980 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x215/0x260 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1098 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa3/0xe0 kernel/locking/spinlock.c:184 Code: 48 c7 c0 88 82 f1 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 2f 48 83 3d 7c 31 d8 01 00 74 15 48 89 df 57 9d <0f> 1f 44 00 00 eb b2 e8 fb eb e6 f8 eb c0 0f 0b 0f 0b 48 c7 c7 88 RSP: 0018:ffff888092d1f3c0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff13e3051 RBX: 0000000000000286 RCX: 1ffff1101381058c RDX: dffffc0000000000 RSI: ffff88809c082c68 RDI: 0000000000000286 RBP: ffffffff89f888d8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88813bff0040 R15: 00000000000000c0 __rcu_read_unlock+0x158/0x160 kernel/rcu/tree_plugin.h:428 rcu_read_unlock include/linux/rcupdate.h:680 [inline] is_bpf_text_address+0xdf/0x1b0 kernel/bpf/core.c:548 kernel_text_address kernel/extable.c:152 [inline] kernel_text_address+0xbd/0xf0 kernel/extable.c:122 __kernel_text_address+0x9/0x30 kernel/extable.c:107 unwind_get_return_address arch/x86/kernel/unwind_orc.c:297 [inline] unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_orc.c:292 __save_stack_trace+0xaf/0x190 arch/x86/kernel/stacktrace.c:45 save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:553 slab_post_alloc_hook mm/slab.h:445 [inline] slab_alloc_node mm/slab.c:3340 [inline] kmem_cache_alloc_node_trace+0x13c/0x3b0 mm/slab.c:3666 kmalloc_node include/linux/slab.h:553 [inline] init_cache_node+0x39/0x170 mm/slab.c:869 setup_kmem_cache_node+0x102/0x510 mm/slab.c:938 setup_kmem_cache_nodes mm/slab.c:3837 [inline] __do_tune_cpucache+0x161/0x210 mm/slab.c:3907 do_tune_cpucache mm/slab.c:3916 [inline] enable_cpucache+0x50/0x130 mm/slab.c:3997 __kmem_cache_create+0x1a7/0x260 mm/slab.c:2152 create_cache+0xd1/0x1f0 mm/slab_common.c:392 kmem_cache_create_usercopy+0x1a6/0x240 mm/slab_common.c:488 p9_client_create+0xcb5/0x12e0 net/9p/client.c:1076 v9fs_session_init+0x1dd/0x1770 fs/9p/v9fs.c:421 v9fs_mount+0x73/0x910 fs/9p/vfs_super.c:135 mount_fs+0xa3/0x310 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2492 [inline] do_mount+0x115c/0x2f50 fs/namespace.c:2822 ksys_mount+0xcf/0x130 fs/namespace.c:3038 __do_sys_mount fs/namespace.c:3052 [inline] __se_sys_mount fs/namespace.c:3049 [inline] __x64_sys_mount+0xba/0x150 fs/namespace.c:3049 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fdc326a8049 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fdc3101d168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fdc327baf60 RCX: 00007fdc326a8049 RDX: 0000000020000040 RSI: 0000000020000000 RDI: 0000000000000000 RBP: 00007fdc3270208d R08: 0000000020000300 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe3e538dcf R14: 00007fdc3101d300 R15: 0000000000022000 Allocated by task 21321: __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15a/0x3c0 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] sk_prot_alloc+0x1e2/0x2d0 net/core/sock.c:1483 sk_alloc+0x36/0xec0 net/core/sock.c:1537 packet_create+0x117/0x850 net/packet/af_packet.c:3259 __sock_create+0x3d8/0x740 net/socket.c:1365 sock_create net/socket.c:1416 [inline] __sys_socket+0xef/0x200 net/socket.c:1458 __do_sys_socket net/socket.c:1467 [inline] __se_sys_socket net/socket.c:1465 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1465 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 21321: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 sk_prot_free net/core/sock.c:1520 [inline] __sk_destruct+0x684/0x8a0 net/core/sock.c:1602 sk_destruct net/core/sock.c:1617 [inline] __sk_free+0x165/0x3b0 net/core/sock.c:1628 sk_free+0x3b/0x50 net/core/sock.c:1639 sock_put include/net/sock.h:1713 [inline] packet_release+0x890/0xb70 net/packet/af_packet.c:3088 __sock_release+0xcd/0x2a0 net/socket.c:599 sock_close+0x15/0x20 net/socket.c:1214 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xbf3/0x2be0 kernel/exit.c:870 do_group_exit+0x125/0x310 kernel/exit.c:967 get_signal+0x3f2/0x1f70 kernel/signal.c:2589 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a0448340 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 1836 bytes inside of 4096-byte region [ffff8880a0448340, ffff8880a0449340) The buggy address belongs to the page: page:ffffea0002811200 count:1 mapcount:0 mapping:ffff88813bff0dc0 index:0x0 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffffea00026df288 ffffea0002811288 ffff88813bff0dc0 raw: 0000000000000000 ffff8880a0448340 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a0448900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a0448980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a0448a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a0448a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a0448b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 48 c7 c0 88 82 f1 89 mov $0xffffffff89f18288,%rax 7: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx e: fc ff df 11: 48 c1 e8 03 shr $0x3,%rax 15: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1) 19: 75 2f jne 0x4a 1b: 48 83 3d 7c 31 d8 01 cmpq $0x0,0x1d8317c(%rip) # 0x1d8319f 22: 00 23: 74 15 je 0x3a 25: 48 89 df mov %rbx,%rdi 28: 57 push %rdi 29: 9d popfq * 2a: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) <-- trapping instruction 2f: eb b2 jmp 0xffffffe3 31: e8 fb eb e6 f8 callq 0xf8e6ec31 36: eb c0 jmp 0xfffffff8 38: 0f 0b ud2 3a: 0f 0b ud2 3c: 48 rex.W 3d: c7 .byte 0xc7 3e: c7 (bad) 3f: 88 .byte 0x88