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authorPeter Hurley <peter@hurleysoftware.com>2013-03-08 12:43:27 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-03-08 15:05:33 -0800
commit88b9e456b1649722673ffa147914299799dc9041 (patch)
treecb2c12ee6fc4ad53e1a15c4e19f676b1d0058183
parente1082f45f1e2bbf6e25f6b614fc6616ebf709d19 (diff)
ipc: don't allocate a copy larger than max
When MSG_COPY is set, a duplicate message must be allocated for the copy before locking the queue. However, the copy could not be larger than was sent which is limited to msg_ctlmax. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--ipc/msg.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/ipc/msg.c b/ipc/msg.c
index 950572f9d79..31cd1bf6af2 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -820,15 +820,17 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
struct msg_msg *copy = NULL;
unsigned long copy_number = 0;
+ ns = current->nsproxy->ipc_ns;
+
if (msqid < 0 || (long) bufsz < 0)
return -EINVAL;
if (msgflg & MSG_COPY) {
- copy = prepare_copy(buf, bufsz, msgflg, &msgtyp, &copy_number);
+ copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax),
+ msgflg, &msgtyp, &copy_number);
if (IS_ERR(copy))
return PTR_ERR(copy);
}
mode = convert_mode(&msgtyp, msgflg);
- ns = current->nsproxy->ipc_ns;
msq = msg_lock_check(ns, msqid);
if (IS_ERR(msq)) {