From e1082f45f1e2bbf6e25f6b614fc6616ebf709d19 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Fri, 8 Mar 2013 12:43:26 -0800 Subject: ipc: fix potential oops when src msg > 4k w/ MSG_COPY If the src msg is > 4k, then dest->next points to the next allocated segment; resetting it just prior to dereferencing is bad. Signed-off-by: Peter Hurley Acked-by: Stanislav Kinsbursky Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- ipc/msgutil.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'ipc') diff --git a/ipc/msgutil.c b/ipc/msgutil.c index ebfcbfa8b7f..5df8e4bf1db 100644 --- a/ipc/msgutil.c +++ b/ipc/msgutil.c @@ -117,9 +117,6 @@ struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst) if (alen > DATALEN_MSG) alen = DATALEN_MSG; - dst->next = NULL; - dst->security = NULL; - memcpy(dst + 1, src + 1, alen); len -= alen; -- cgit v1.2.3-70-g09d2 From 88b9e456b1649722673ffa147914299799dc9041 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Fri, 8 Mar 2013 12:43:27 -0800 Subject: 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 Acked-by: Stanislav Kinsbursky Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- ipc/msg.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'ipc') 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, ©_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)) { -- cgit v1.2.3-70-g09d2