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authorSasha Levin <levinsasha928@gmail.com>2012-04-05 08:07:45 -0400
committerDavid S. Miller <davem@davemloft.net>2012-04-05 19:05:56 -0400
commitbcf1b70ac6eb0ed8286c66e6bf37cb747cbaa04c (patch)
tree915bba04ae97f738256fa0e814d5da298ca90688 /net/phonet/pep.c
parent35f9c09fe9c72eb8ca2b8e89a593e1c151f28fc2 (diff)
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@gmail.com> Acked-by: RĂ©mi Denis-Courmont <remi.denis-courmont@nokia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/phonet/pep.c')
-rw-r--r--net/phonet/pep.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/net/phonet/pep.c b/net/phonet/pep.c
index 9f60008740e3..9726fe684ab8 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,
1130 int flags = msg->msg_flags; 1130 int flags = msg->msg_flags;
1131 int err, done; 1131 int err, done;
1132 1132
1133 if (len > USHRT_MAX)
1134 return -EMSGSIZE;
1135
1133 if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL| 1136 if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
1134 MSG_CMSG_COMPAT)) || 1137 MSG_CMSG_COMPAT)) ||
1135 !(msg->msg_flags & MSG_EOR)) 1138 !(msg->msg_flags & MSG_EOR))