| From | Greg Kroah-Hartman <> | Subject | [ 058/100] ipc: dont allocate a copy larger than max | Date | Tue, 12 Mar 2013 15:31:43 -0700 |
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3.8-stable review patch. If anyone has any objections, please let me know.
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From: Peter Hurley <peter@hurleysoftware.com>
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@hurleysoftware.com> Acked-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- 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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