netdev - [PATCH] phonet: Check input from user before allocating

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Mon,  2 Apr 2012 16:31:00 -0400
From:	Sasha Levin <levinsasha928@...il.com>
To:	remi.denis-courmont@...ia.com, davem@...emloft.net
Cc:	davej@...hat.com, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org, Sasha Levin <levinsasha928@...il.com>
Subject: [PATCH] phonet: Check input from user before allocating

A phonet packet is limited to USHRT_MAX bytes, this is never checked during
tx which means that the user can specify any size he wishes, and the kernel
will attempt to allocate that size.

In the good case, it'll lead to the following warning, but it may also cause
the kernel to kick in the OOM and kill a random task on the server.

[ 8921.744094] WARNING: at mm/page_alloc.c:2255 __alloc_pages_slowpath+0x65/0x730()
[ 8921.749770] Pid: 5081, comm: trinity Tainted: G        W    3.4.0-rc1-next-20120402-sasha #46
[ 8921.756672] Call Trace:
[ 8921.758185]  [<ffffffff810b2ba7>] warn_slowpath_common+0x87/0xb0
[ 8921.762868]  [<ffffffff810b2be5>] warn_slowpath_null+0x15/0x20
[ 8921.765399]  [<ffffffff8117eae5>] __alloc_pages_slowpath+0x65/0x730
[ 8921.769226]  [<ffffffff81179c8a>] ? zone_watermark_ok+0x1a/0x20
[ 8921.771686]  [<ffffffff8117d045>] ? get_page_from_freelist+0x625/0x660
[ 8921.773919]  [<ffffffff8117f3a8>] __alloc_pages_nodemask+0x1f8/0x240
[ 8921.776248]  [<ffffffff811c03e0>] kmalloc_large_node+0x70/0xc0
[ 8921.778294]  [<ffffffff811c4bd4>] __kmalloc_node_track_caller+0x34/0x1c0
[ 8921.780847]  [<ffffffff821b0e3c>] ? sock_alloc_send_pskb+0xbc/0x260
[ 8921.783179]  [<ffffffff821b3c65>] __alloc_skb+0x75/0x170
[ 8921.784971]  [<ffffffff821b0e3c>] sock_alloc_send_pskb+0xbc/0x260
[ 8921.787111]  [<ffffffff821b002e>] ? release_sock+0x7e/0x90
[ 8921.788973]  [<ffffffff821b0ff0>] sock_alloc_send_skb+0x10/0x20
[ 8921.791052]  [<ffffffff824cfc20>] pep_sendmsg+0x60/0x380
[ 8921.792931]  [<ffffffff824cb4a6>] ? pn_socket_bind+0x156/0x180
[ 8921.794917]  [<ffffffff824cb50f>] ? pn_socket_autobind+0x3f/0x90
[ 8921.797053]  [<ffffffff824cb63f>] pn_socket_sendmsg+0x4f/0x70
[ 8921.798992]  [<ffffffff821ab8e7>] sock_aio_write+0x187/0x1b0
[ 8921.801395]  [<ffffffff810e325e>] ? sub_preempt_count+0xae/0xf0
[ 8921.803501]  [<ffffffff8111842c>] ? __lock_acquire+0x42c/0x4b0
[ 8921.805505]  [<ffffffff821ab760>] ? __sock_recv_ts_and_drops+0x140/0x140
[ 8921.807860]  [<ffffffff811e07cc>] do_sync_readv_writev+0xbc/0x110
[ 8921.809986]  [<ffffffff811958e7>] ? might_fault+0x97/0xa0
[ 8921.811998]  [<ffffffff817bd99e>] ? security_file_permission+0x1e/0x90
[ 8921.814595]  [<ffffffff811e17e2>] do_readv_writev+0xe2/0x1e0
[ 8921.816702]  [<ffffffff810b8dac>] ? do_setitimer+0x1ac/0x200
[ 8921.818819]  [<ffffffff810e2ec1>] ? get_parent_ip+0x11/0x50
[ 8921.820863]  [<ffffffff810e325e>] ? sub_preempt_count+0xae/0xf0
[ 8921.823318]  [<ffffffff811e1926>] vfs_writev+0x46/0x60
[ 8921.825219]  [<ffffffff811e1a3f>] sys_writev+0x4f/0xb0
[ 8921.827127]  [<ffffffff82658039>] system_call_fastpath+0x16/0x1b
[ 8921.829384] ---[ end trace dffe390f30db9eb7 ]---

Signed-off-by: Sasha Levin <levinsasha928@...il.com>
---
 net/phonet/pep.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/net/phonet/pep.c b/net/phonet/pep.c
index 9f60008..caee99e 100644
--- a/net/phonet/pep.c
+++ b/net/phonet/pep.c
@@ -1130,6 +1130,9 @@ static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
 	int flags = msg->msg_flags;
 	int err, done;
 
+	if (len > USHRT_MAX)
+		return -E2BIG;
+
 	if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
 				MSG_CMSG_COMPAT)) ||
 			!(msg->msg_flags & MSG_EOR))
-- 
1.7.8.5

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html