[13/28] relay: prevent integer overflow in relay_open()
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2012-02-17 01:06:21
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lkml
3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter <redacted> commit f6302f1bcd75a042df69866d98b8d775a668f8f1 upstream. "subbuf_size" and "n_subbufs" come from the user and they need to be capped to prevent an integer overflow. Signed-off-by: Dan Carpenter <redacted> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- kernel/relay.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
--- a/kernel/relay.c
+++ b/kernel/relay.c@@ -164,10 +164,14 @@ depopulate: */ static struct rchan_buf *relay_create_buf(struct rchan *chan) { - struct rchan_buf *buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL); - if (!buf) + struct rchan_buf *buf; + + if (chan->n_subbufs > UINT_MAX / sizeof(size_t *)) return NULL; + buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL); + if (!buf) + return NULL; buf->padding = kmalloc(chan->n_subbufs * sizeof(size_t *), GFP_KERNEL); if (!buf->padding) goto free_buf;
@@ -574,6 +578,8 @@ struct rchan *relay_open(const char *bas if (!(subbuf_size && n_subbufs)) return NULL; + if (subbuf_size > UINT_MAX / n_subbufs) + return NULL; chan = kzalloc(sizeof(struct rchan), GFP_KERNEL); if (!chan)