All of lore.kernel.org
 help / color / mirror / Atom feed
From: syzbot <syzbot+5be8aebb1b7dfa90ef31@syzkaller.appspotmail.com>
To: davem@davemloft.net, herbert@gondor.apana.org.au,
	kuba@kernel.org, linux-kernel@vger.kernel.org,
	netdev@vger.kernel.org, steffen.klassert@secunet.com,
	syzkaller-bugs@googlegroups.com
Subject: KASAN: use-after-free Read in decode_session6
Date: Sun, 28 Jun 2020 21:55:11 -0700	[thread overview]
Message-ID: <00000000000013259505a931dd26@google.com> (raw)

Hello,

syzbot found the following crash on:

HEAD commit:    b08866f4 Merge branch 'net-atlantic-various-non-functional..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17096b55100000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2172f4d0dbc37e27
dashboard link: https://syzkaller.appspot.com/bug?extid=5be8aebb1b7dfa90ef31
compiler:       gcc (GCC) 10.1.0-syz 20200507

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+5be8aebb1b7dfa90ef31@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in decode_session6+0xe7c/0x1580 net/xfrm/xfrm_policy.c:3389
Read of size 1 at addr ffff88808f61c0ad by task syz-executor.3/13170

CPU: 0 PID: 13170 Comm: syz-executor.3 Not tainted 5.8.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 decode_session6+0xe7c/0x1580 net/xfrm/xfrm_policy.c:3389
 __xfrm_decode_session+0x50/0xb0 net/xfrm/xfrm_policy.c:3481
 xfrm_decode_session include/net/xfrm.h:1135 [inline]
 vti6_tnl_xmit+0x40d/0x1c80 net/ipv6/ip6_vti.c:577
 __netdev_start_xmit include/linux/netdevice.h:4611 [inline]
 netdev_start_xmit include/linux/netdevice.h:4625 [inline]
 xmit_one net/core/dev.c:3562 [inline]
 dev_hard_start_xmit+0x193/0x950 net/core/dev.c:3578
 sch_direct_xmit+0x2ea/0xc00 net/sched/sch_generic.c:313
 qdisc_restart net/sched/sch_generic.c:376 [inline]
 __qdisc_run+0x4b9/0x1630 net/sched/sch_generic.c:384
 __dev_xmit_skb net/core/dev.c:3801 [inline]
 __dev_queue_xmit+0x1995/0x2d60 net/core/dev.c:4106
 neigh_output include/net/neighbour.h:509 [inline]
 ip6_finish_output2+0x8b6/0x17b0 net/ipv6/ip6_output.c:117
 __ip6_finish_output net/ipv6/ip6_output.c:143 [inline]
 __ip6_finish_output+0x447/0xab0 net/ipv6/ip6_output.c:128
 ip6_finish_output+0x34/0x1f0 net/ipv6/ip6_output.c:153
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x1db/0x520 net/ipv6/ip6_output.c:176
 dst_output include/net/dst.h:435 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 mld_sendpack+0x92a/0xdb0 net/ipv6/mcast.c:1679
 mld_send_cr net/ipv6/mcast.c:1975 [inline]
 mld_ifc_timer_expire+0x60a/0xf10 net/ipv6/mcast.c:2474
 call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers.part.0+0x54c/0xa20 kernel/time/timer.c:1773
 __run_timers kernel/time/timer.c:1745 [inline]
 run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1786
 __do_softirq+0x34c/0xa60 kernel/softirq.c:292
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 do_softirq_own_stack+0x111/0x170 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:387 [inline]
 __irq_exit_rcu kernel/softirq.c:417 [inline]
 irq_exit_rcu+0x229/0x270 kernel/softirq.c:429
 sysvec_apic_timer_interrupt+0x12d/0x220 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:596
RIP: 0010:ip_sk_use_pmtu include/net/ip.h:425 [inline]
RIP: 0010:ip_setup_cork+0x171/0x910 net/ipv4/ip_output.c:1265
Code: 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 fd 05 00 00 44 89 7b 04 <e8> 2a ce cc fa 49 8d bc 24 df 04 00 00 48 b8 00 00 00 00 00 fc ff
RSP: 0018:ffffc90004b47260 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffc90004b47568 RCX: ffffc9000ff09000
RDX: 1ffff92000968e9a RSI: ffffffff86a680fc RDI: ffffc90004b474d0
RBP: ffffc90004b474b8 R08: 0000000000000008 R09: 0000000000000008
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88809458a000
R13: ffffc90004b47498 R14: ffff8880a1c86400 R15: 0000000000000000
 ip_make_skb+0x174/0x2a0 net/ipv4/ip_output.c:1628
 udp_sendmsg+0x1c2d/0x26c0 net/ipv4/udp.c:1176
 udpv6_sendmsg+0x14dd/0x2b90 net/ipv6/udp.c:1286
 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:638
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x331/0x810 net/socket.c:2352
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2406
 __sys_sendmmsg+0x195/0x480 net/socket.c:2496
 __do_sys_sendmmsg net/socket.c:2525 [inline]
 __se_sys_sendmmsg net/socket.c:2522 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2522
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb19
Code: Bad RIP value.
RSP: 002b:00007f459bcffc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000004fd680 RCX: 000000000045cb19
RDX: 00000000000005c3 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000902 R14: 00000000004cbde8 R15: 00007f459bd006d4

Allocated by task 13105:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494
 kmem_cache_alloc_trace+0x14f/0x2d0 mm/slab.c:3551
 kmalloc include/linux/slab.h:555 [inline]
 kzalloc include/linux/slab.h:669 [inline]
 kobject_uevent_env+0x227/0x12c0 lib/kobject_uevent.c:523
 netdev_queue_add_kobject net/core/net-sysfs.c:1554 [inline]
 netdev_queue_update_kobjects+0x2f9/0x3c0 net/core/net-sysfs.c:1588
 register_queue_kobjects net/core/net-sysfs.c:1649 [inline]
 netdev_register_kobject+0x2ee/0x3b0 net/core/net-sysfs.c:1892
 register_netdevice+0xd29/0x1540 net/core/dev.c:9522
 __tun_chr_ioctl.isra.0+0x2c09/0x4170 drivers/net/tun.c:2817
 vfs_ioctl fs/ioctl.c:48 [inline]
 ksys_ioctl+0x11a/0x180 fs/ioctl.c:753
 __do_sys_ioctl fs/ioctl.c:762 [inline]
 __se_sys_ioctl fs/ioctl.c:760 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 13110:
 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+0xf5/0x140 mm/kasan/common.c:455
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x103/0x2c0 mm/slab.c:3757
 call_usermodehelper_freeinfo kernel/umh.c:47 [inline]
 umh_complete+0x74/0x90 kernel/umh.c:62
 call_usermodehelper_exec_async+0x460/0x710 kernel/umh.c:122
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

The buggy address belongs to the object at ffff88808f61c000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 173 bytes inside of
 4096-byte region [ffff88808f61c000, ffff88808f61d000)
The buggy address belongs to the page:
page:ffffea00023d8700 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 head:ffffea00023d8700 order:1 compound_mapcount:0
flags: 0xfffe0000010200(slab|head)
raw: 00fffe0000010200 ffffea0001af9708 ffffea000140d688 ffff8880aa002000
raw: 0000000000000000 ffff88808f61c000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808f61bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808f61c000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88808f61c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88808f61c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808f61c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

             reply	other threads:[~2020-06-29 21:00 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-29  4:55 syzbot [this message]
2020-10-31 16:43 ` KASAN: use-after-free Read in decode_session6 syzbot
2020-11-01  5:40 ` syzbot
2020-11-03 13:14   ` Xin Long
2020-11-03 13:52     ` Xin Long

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=00000000000013259505a931dd26@google.com \
    --to=syzbot+5be8aebb1b7dfa90ef31@syzkaller.appspotmail.com \
    --cc=davem@davemloft.net \
    --cc=herbert@gondor.apana.org.au \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=steffen.klassert@secunet.com \
    --cc=syzkaller-bugs@googlegroups.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.