[ 058/100] ipc: dont allocate a copy larger than max
From: Greg Kroah-Hartman
Date: Tue Mar 12 2013 - 19:03:50 EST
3.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
commit 88b9e456b1649722673ffa147914299799dc9041 upstream.
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@xxxxxxxxxxxxxxxxxx>
Acked-by: Stanislav Kinsbursky <skinsbursky@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
ipc/msg.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -820,15 +820,17 @@ long do_msgrcv(int msqid, void __user *b
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, ©_number);
+ copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax),
+ msgflg, &msgtyp, ©_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)) {
--
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