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authorDoug Ledford <dledford@redhat.com>2012-05-31 16:26:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-31 17:49:31 -0700
commit113289cc086f80f28acd06f160a7c6423cdd4191 (patch)
tree4a50ff35f9cc0b320985a76b5f2e8313635b0f81 /ipc
parent2c12ea498f349207c28840c0ed9654321aab7720 (diff)
downloadlinux-stericsson-113289cc086f80f28acd06f160a7c6423cdd4191.tar.gz
ipc/mqueue: strengthen checks on mqueue creation
We already check the mq attr struct if it's passed in, but now that the admin can set system wide defaults separate from maximums, it's actually possible to set the defaults to something that would overflow. So, if there is no attr struct passed in to the open call, check the default values. While we are at it, simplify mq_attr_ok() by making it return 0 or an error condition, so that way if we add more tests to it later, we have the option of what error should be returned instead of the calling location having to pick a possibly inaccurate error code. [akpm@linux-foundation.org: s/ENOMEM/EOVERFLOW/] Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Manfred Spraul <manfred@colorfullife.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc')
-rw-r--r--ipc/mqueue.c27
1 files changed, 18 insertions, 9 deletions
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 076399ce363a..af1692556c52 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -680,26 +680,26 @@ static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
unsigned long total_size;
if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
- return 0;
+ return -EINVAL;
if (capable(CAP_SYS_RESOURCE)) {
if (attr->mq_maxmsg > HARD_MSGMAX ||
attr->mq_msgsize > HARD_MSGSIZEMAX)
- return 0;
+ return -EINVAL;
} else {
if (attr->mq_maxmsg > ipc_ns->mq_msg_max ||
attr->mq_msgsize > ipc_ns->mq_msgsize_max)
- return 0;
+ return -EINVAL;
}
/* check for overflow */
if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg)
- return 0;
+ return -EOVERFLOW;
mq_treesize = attr->mq_maxmsg * sizeof(struct msg_msg) +
min_t(unsigned int, attr->mq_maxmsg, MQ_PRIO_MAX) *
sizeof(struct posix_msg_tree_node);
total_size = attr->mq_maxmsg * attr->mq_msgsize;
if (total_size + mq_treesize < total_size)
- return 0;
- return 1;
+ return -EOVERFLOW;
+ return 0;
}
/*
@@ -714,12 +714,21 @@ static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir,
int ret;
if (attr) {
- if (!mq_attr_ok(ipc_ns, attr)) {
- ret = -EINVAL;
+ ret = mq_attr_ok(ipc_ns, attr);
+ if (ret)
goto out;
- }
/* store for use during create */
dentry->d_fsdata = attr;
+ } else {
+ struct mq_attr def_attr;
+
+ def_attr.mq_maxmsg = min(ipc_ns->mq_msg_max,
+ ipc_ns->mq_msg_default);
+ def_attr.mq_msgsize = min(ipc_ns->mq_msgsize_max,
+ ipc_ns->mq_msgsize_default);
+ ret = mq_attr_ok(ipc_ns, &def_attr);
+ if (ret)
+ goto out;
}
mode &= ~current_umask();