From: David Miller <davem@davemloft.net>
To: lucien.xin@gmail.com
Cc: netdev@vger.kernel.org, fw@strlen.de, chunwang@redhat.com,
syzkaller@googlegroups.com
Subject: Re: [PATCH net] netlink: fix an use-after-free issue for nlk groups
Date: Wed, 06 Sep 2017 21:24:19 -0700 (PDT) [thread overview]
Message-ID: <20170906.212419.1982531430917223449.davem@davemloft.net> (raw)
In-Reply-To: <1217baf9faf9d034ba8224cb6362b822c51a0eae.1504669632.git.lucien.xin@gmail.com>
From: Xin Long <lucien.xin@gmail.com>
Date: Wed, 6 Sep 2017 11:47:12 +0800
> ChunYu found a netlink use-after-free issue by syzkaller:
>
> [28448.842981] BUG: KASAN: use-after-free in __nla_put+0x37/0x40 at addr ffff8807185e2378
> [28448.969918] Call Trace:
> [...]
> [28449.117207] __nla_put+0x37/0x40
> [28449.132027] nla_put+0xf5/0x130
> [28449.146261] sk_diag_fill.isra.4.constprop.5+0x5a0/0x750 [netlink_diag]
> [28449.176608] __netlink_diag_dump+0x25a/0x700 [netlink_diag]
> [28449.202215] netlink_diag_dump+0x176/0x240 [netlink_diag]
> [28449.226834] netlink_dump+0x488/0xbb0
> [28449.298014] __netlink_dump_start+0x4e8/0x760
> [28449.317924] netlink_diag_handler_dump+0x261/0x340 [netlink_diag]
> [28449.413414] sock_diag_rcv_msg+0x207/0x390
> [28449.432409] netlink_rcv_skb+0x149/0x380
> [28449.467647] sock_diag_rcv+0x2d/0x40
> [28449.484362] netlink_unicast+0x562/0x7b0
> [28449.564790] netlink_sendmsg+0xaa8/0xe60
> [28449.661510] sock_sendmsg+0xcf/0x110
> [28449.865631] __sys_sendmsg+0xf3/0x240
> [28450.000964] SyS_sendmsg+0x32/0x50
> [28450.016969] do_syscall_64+0x25c/0x6c0
> [28450.154439] entry_SYSCALL64_slow_path+0x25/0x25
>
> It was caused by no protection between nlk groups' free in netlink_release
> and nlk groups' accessing in sk_diag_dump_groups. The similar issue also
> exists in netlink_seq_show().
>
> This patch is to defer nlk groups' free in deferred_put_nlk_sk.
>
> Reported-by: ChunYu Wang <chunwang@redhat.com>
> Acked-by: Florian Westphal <fw@strlen.de>
> Signed-off-by: Xin Long <lucien.xin@gmail.com>
Applied.
next prev parent reply other threads:[~2017-09-07 4:24 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-06 3:47 [PATCH net] netlink: fix an use-after-free issue for nlk groups Xin Long
2017-09-07 4:24 ` David Miller [this message]
2017-09-08 21:56 ` Cong Wang
2017-09-10 12:02 ` 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=20170906.212419.1982531430917223449.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=chunwang@redhat.com \
--cc=fw@strlen.de \
--cc=lucien.xin@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=syzkaller@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).