4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: David Rientjes <[email protected]> [ Upstream commit 88913bd8ea2a75d7e460a4bed5f75e1c32660d7e ] chan->n_subbufs is set by the user and relay_create_buf() does a kmalloc() of chan->n_subbufs * sizeof(size_t *). kmalloc_slab() will generate a warning when this fails if chan->subbufs * sizeof(size_t *) > KMALLOC_MAX_SIZE. Limit chan->n_subbufs to the maximum allowed kmalloc() size. Link: http://lkml.kernel.org/r/[email protected] Fixes: f6302f1bcd75 ("relay: prevent integer overflow in relay_open()") Signed-off-by: David Rientjes <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Jens Axboe <[email protected]> Cc: Dave Jiang <[email protected]> Cc: Al Viro <[email protected]> Cc: Dan Carpenter <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- kernel/relay.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/relay.c +++ b/kernel/relay.c @@ -163,7 +163,7 @@ static struct rchan_buf *relay_create_bu { struct rchan_buf *buf; - if (chan->n_subbufs > UINT_MAX / sizeof(size_t *)) + if (chan->n_subbufs > KMALLOC_MAX_SIZE / sizeof(size_t *)) return NULL; buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL);
