From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967559AbdAIRL4 (ORCPT ); Mon, 9 Jan 2017 12:11:56 -0500 Received: from mail-oi0-f44.google.com ([209.85.218.44]:36765 "EHLO mail-oi0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763273AbdAIRLb (ORCPT ); Mon, 9 Jan 2017 12:11:31 -0500 MIME-Version: 1.0 In-Reply-To: References: From: Andrey Konovalov Date: Mon, 9 Jan 2017 18:11:30 +0100 Message-ID: Subject: Re: net/ipv6: use-after-free in sock_wfree To: "David S. Miller" , Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Patrick McHardy , netdev , LKML Cc: Dmitry Vyukov , Kostya Serebryany , Eric Dumazet , syzkaller Content-Type: text/plain; charset=UTF-8 X-ccpol: medium Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 9, 2017 at 6:08 PM, Andrey Konovalov wrote: > Hi! > > I've got the following error report while running the syzkaller fuzzer. > > On commit a121103c922847ba5010819a3f250f1f7fc84ab8 (4.10-rc3). > > A reproducer is attached. > > ================================================================== > BUG: KASAN: use-after-free in sock_wfree+0x118/0x120 > Read of size 8 at addr ffff880062da0060 by task a.out/4140 > > page:ffffea00018b6800 count:1 mapcount:0 mapping: (null) > index:0x0 compound_mapcount: 0 > flags: 0x100000000008100(slab|head) > raw: 0100000000008100 0000000000000000 0000000000000000 0000000180130013 > raw: dead000000000100 dead000000000200 ffff88006741f140 0000000000000000 > page dumped because: kasan: bad access detected > > CPU: 0 PID: 4140 Comm: a.out Not tainted 4.10.0-rc3+ #59 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:15 > dump_stack+0x292/0x398 lib/dump_stack.c:51 > describe_address mm/kasan/report.c:262 > kasan_report_error+0x121/0x560 mm/kasan/report.c:370 > kasan_report mm/kasan/report.c:392 > __asan_report_load8_noabort+0x3e/0x40 mm/kasan/report.c:413 > sock_flag ./arch/x86/include/asm/bitops.h:324 > sock_wfree+0x118/0x120 net/core/sock.c:1631 > skb_release_head_state+0xfc/0x250 net/core/skbuff.c:655 > skb_release_all+0x15/0x60 net/core/skbuff.c:668 > __kfree_skb+0x15/0x20 net/core/skbuff.c:684 > kfree_skb+0x16e/0x4e0 net/core/skbuff.c:705 > inet_frag_destroy+0x121/0x290 net/ipv4/inet_fragment.c:304 > inet_frag_put ./include/net/inet_frag.h:133 > nf_ct_frag6_gather+0x1125/0x38b0 net/ipv6/netfilter/nf_conntrack_reasm.c:617 > ipv6_defrag+0x21b/0x350 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:68 > nf_hook_entry_hookfn ./include/linux/netfilter.h:102 > nf_hook_slow+0xc3/0x290 net/netfilter/core.c:310 > nf_hook ./include/linux/netfilter.h:212 > __ip6_local_out+0x52c/0xaf0 net/ipv6/output_core.c:160 > ip6_local_out+0x2d/0x170 net/ipv6/output_core.c:170 > ip6_send_skb+0xa1/0x340 net/ipv6/ip6_output.c:1722 > ip6_push_pending_frames+0xb3/0xe0 net/ipv6/ip6_output.c:1742 > rawv6_push_pending_frames net/ipv6/raw.c:613 > rawv6_sendmsg+0x2cff/0x4130 net/ipv6/raw.c:927 > inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:744 > sock_sendmsg_nosec net/socket.c:635 > sock_sendmsg+0xca/0x110 net/socket.c:645 > sock_write_iter+0x326/0x620 net/socket.c:848 > new_sync_write fs/read_write.c:499 > __vfs_write+0x483/0x760 fs/read_write.c:512 > vfs_write+0x187/0x530 fs/read_write.c:560 > SYSC_write fs/read_write.c:607 > SyS_write+0xfb/0x230 fs/read_write.c:599 > entry_SYSCALL_64_fastpath+0x1f/0xc2 arch/x86/entry/entry_64.S:203 > RIP: 0033:0x7ff26e6f5b79 > RSP: 002b:00007ff268e0ed98 EFLAGS: 00000206 ORIG_RAX: 0000000000000001 > RAX: ffffffffffffffda RBX: 00007ff268e0f9c0 RCX: 00007ff26e6f5b79 > RDX: 0000000000000010 RSI: 0000000020f50fe1 RDI: 0000000000000003 > RBP: 00007ff26ebc1220 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 > R13: 00007ff268e0f9c0 R14: 00007ff26efec040 R15: 0000000000000003 > > The buggy address belongs to the object at ffff880062da0000 > which belongs to the cache RAWv6 of size 1504 > The buggy address ffff880062da0060 is located 96 bytes inside > of 1504-byte region [ffff880062da0000, ffff880062da05e0) > > Freed by task 4113: > save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 > save_stack+0x43/0xd0 mm/kasan/kasan.c:502 > set_track mm/kasan/kasan.c:514 > kasan_slab_free+0x73/0xc0 mm/kasan/kasan.c:578 > slab_free_hook mm/slub.c:1352 > slab_free_freelist_hook mm/slub.c:1374 > slab_free mm/slub.c:2951 > kmem_cache_free+0xb2/0x2c0 mm/slub.c:2973 > sk_prot_free net/core/sock.c:1377 > __sk_destruct+0x49c/0x6e0 net/core/sock.c:1452 > sk_destruct+0x47/0x80 net/core/sock.c:1460 > __sk_free+0x57/0x230 net/core/sock.c:1468 > sk_free+0x23/0x30 net/core/sock.c:1479 > sock_put ./include/net/sock.h:1638 > sk_common_release+0x31e/0x4e0 net/core/sock.c:2782 > rawv6_close+0x54/0x80 net/ipv6/raw.c:1214 > inet_release+0xed/0x1c0 net/ipv4/af_inet.c:425 > inet6_release+0x50/0x70 net/ipv6/af_inet6.c:431 > sock_release+0x8d/0x1e0 net/socket.c:599 > sock_close+0x16/0x20 net/socket.c:1063 > __fput+0x332/0x7f0 fs/file_table.c:208 > ____fput+0x15/0x20 fs/file_table.c:244 > task_work_run+0x19b/0x270 kernel/task_work.c:116 > exit_task_work ./include/linux/task_work.h:21 > do_exit+0x186b/0x2800 kernel/exit.c:839 > do_group_exit+0x149/0x420 kernel/exit.c:943 > SYSC_exit_group kernel/exit.c:954 > SyS_exit_group+0x1d/0x20 kernel/exit.c:952 > entry_SYSCALL_64_fastpath+0x1f/0xc2 arch/x86/entry/entry_64.S:203 > > Allocated by task 4115: > save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 > save_stack+0x43/0xd0 mm/kasan/kasan.c:502 > set_track mm/kasan/kasan.c:514 > kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:605 > kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544 > slab_post_alloc_hook mm/slab.h:432 > slab_alloc_node mm/slub.c:2708 > slab_alloc mm/slub.c:2716 > kmem_cache_alloc+0x1af/0x250 mm/slub.c:2721 > sk_prot_alloc+0x65/0x2a0 net/core/sock.c:1334 > sk_alloc+0x105/0x1010 net/core/sock.c:1396 > inet6_create+0x44d/0x1150 net/ipv6/af_inet6.c:183 > __sock_create+0x4f6/0x880 net/socket.c:1199 > sock_create net/socket.c:1239 > SYSC_socket net/socket.c:1269 > SyS_socket+0xf9/0x230 net/socket.c:1249 > entry_SYSCALL_64_fastpath+0x1f/0xc2 arch/x86/entry/entry_64.S:203 > > Memory state around the buggy address: > ffff880062d9ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff880062d9ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >>ffff880062da0000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff880062da0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff880062da0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== Sometimes this reproducer leads to another report: INFO: rcu_sched self-detected stall on CPU 1-...: (1 GPs behind) idle=ead/140000000000001/0 softirq=8122/8123 fqs=6497 (t=26000 jiffies g=3021 c=3020 q=345) Task dump for CPU 1: syz-executor R running task 18904 3943 3941 0x0000000c Call Trace: sched_show_task+0x3fa/0x560 kernel/sched/core.c:5217 dump_cpu_task+0x71/0x90 kernel/sched/core.c:8822 rcu_dump_cpu_stacks+0x318/0x35e kernel/rcu/tree.c:1290 print_cpu_stall+0x39f/0x6e0 kernel/rcu/tree.c:1434 check_cpu_stall.isra.63+0x702/0xe80 kernel/rcu/tree.c:1502 __rcu_pending kernel/rcu/tree.c:3469 rcu_pending kernel/rcu/tree.c:3533 rcu_check_callbacks+0x27f/0xda0 kernel/rcu/tree.c:2867 update_process_times+0x30/0x60 kernel/time/timer.c:1612 tick_sched_handle.isra.18+0xb3/0xe0 kernel/time/tick-sched.c:151 tick_sched_timer+0x72/0x120 kernel/time/tick-sched.c:1158 __run_hrtimer kernel/time/hrtimer.c:1238 __hrtimer_run_queues+0x38c/0xf80 kernel/time/hrtimer.c:1302 hrtimer_interrupt+0x1ab/0x5c0 kernel/time/hrtimer.c:1336 local_apic_timer_interrupt+0x6f/0xe0 arch/x86/kernel/apic/apic.c:936 smp_apic_timer_interrupt+0x71/0xa0 arch/x86/kernel/apic/apic.c:960 apic_timer_interrupt+0x93/0xa0 RIP: 0010:__sanitizer_cov_trace_pc+0x46/0x60 kernel/kcov.c:93 RSP: 0018:ffff88006ad66a98 EFLAGS: 00000216 ORIG_RAX: ffffffffffffff10 RAX: 0000000000004000 RBX: ffff880068f4e500 RCX: ffffc90000e6c000 RDX: 0000000000004000 RSI: ffffffff83d652b7 RDI: ffff880064f09f51 RBP: ffff88006ad66a98 R08: ffffed000d633ca1 R09: ffffed000d633ca1 R10: 0000000000000001 R11: ffffed000d633ca0 R12: ffff880064f00020 R13: ffff88006ad66c28 R14: 0000000000009f38 R15: dffffc0000000000 _decode_session6+0x8a7/0x13f0 net/ipv6/xfrm6_policy.c:147 __xfrm_decode_session+0x63/0x100 net/xfrm/xfrm_policy.c:2475 xfrm_decode_session_reverse ./include/net/xfrm.h:1117 icmpv6_route_lookup+0x410/0x780 net/ipv6/icmp.c:362 icmp6_send+0x1611/0x29b0 net/ipv6/icmp.c:515 icmpv6_send+0x12e/0x260 net/ipv6/ip6_icmp.c:42 ip6_fragment+0x583/0x3920 net/ipv6/ip6_output.c:864 ip6_finish_output+0x322/0x960 net/ipv6/ip6_output.c:146 NF_HOOK_COND ./include/linux/netfilter.h:246 ip6_output+0x1cb/0x8d0 net/ipv6/ip6_output.c:162 dst_output ./include/net/dst.h:501 ip6_local_out+0x95/0x170 net/ipv6/output_core.c:172 ip6_send_skb+0xa1/0x340 net/ipv6/ip6_output.c:1722 ip6_push_pending_frames+0xb3/0xe0 net/ipv6/ip6_output.c:1742 rawv6_push_pending_frames net/ipv6/raw.c:613 rawv6_sendmsg+0x2cff/0x4130 net/ipv6/raw.c:927 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:744 sock_sendmsg_nosec net/socket.c:635 sock_sendmsg+0xca/0x110 net/socket.c:645 sock_write_iter+0x326/0x620 net/socket.c:848 new_sync_write fs/read_write.c:499 __vfs_write+0x483/0x760 fs/read_write.c:512 vfs_write+0x187/0x530 fs/read_write.c:560 SYSC_write fs/read_write.c:607 SyS_write+0xfb/0x230 fs/read_write.c:599 entry_SYSCALL_64_fastpath+0x1f/0xc2 arch/x86/entry/entry_64.S:203 RIP: 0033:0x4421d9 RSP: 002b:00007f090e289b58 EFLAGS: 00000296 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000004421d9 RDX: 000000000000ffff RSI: 0000000020aa4fda RDI: 0000000000000005 RBP: 00000000006de8c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000700000 R13: ffffffffffffffff R14: 0000000020f4a000 R15: 0000000000000010