This is a note to let you know that I've just added the patch titled nvmet: prevent sprintf() overflow in nvmet_subsys_nsid_exists() to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nvmet-prevent-sprintf-overflow-in-nvmet_subsys_nsid_.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 56d8ccdfdeecbff45a88475b88c2d01d314d3c6f Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Date: Wed May 8 10:43:04 2024 +0300 nvmet: prevent sprintf() overflow in nvmet_subsys_nsid_exists() [ Upstream commit d15dcd0f1a4753b57e66c64c8dc2a9779ff96aab ] The nsid value is a u32 that comes from nvmet_req_find_ns(). It's endian data and we're on an error path and both of those raise red flags. So let's make this safer. 1) Make the buffer large enough for any u32. 2) Remove the unnecessary initialization. 3) Use snprintf() instead of sprintf() for even more safety. 4) The sprintf() function returns the number of bytes printed, not counting the NUL terminator. It is impossible for the return value to be <= 0 so delete that. Fixes: 505363957fad ("nvmet: fix nvme status code when namespace is disabled") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Reviewed-by: Sagi Grimberg <sagi@xxxxxxxxxxx> Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c index b1f5fa45bb4ac..40c1c3db5d7cd 100644 --- a/drivers/nvme/target/configfs.c +++ b/drivers/nvme/target/configfs.c @@ -618,10 +618,9 @@ static struct configfs_attribute *nvmet_ns_attrs[] = { bool nvmet_subsys_nsid_exists(struct nvmet_subsys *subsys, u32 nsid) { struct config_item *ns_item; - char name[4] = {}; + char name[12]; - if (sprintf(name, "%u", nsid) <= 0) - return false; + snprintf(name, sizeof(name), "%u", nsid); mutex_lock(&subsys->namespaces_group.cg_subsys->su_mutex); ns_item = config_group_find_item(&subsys->namespaces_group, name); mutex_unlock(&subsys->namespaces_group.cg_subsys->su_mutex);