This is a note to let you know that I've just added the patch titled octeontx2-af: avoid off-by-one read from userspace to the 5.15-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: octeontx2-af-avoid-off-by-one-read-from-userspace.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit d073e68f5a04c4a91775031e485b2a2a531bca76 Author: Bui Quang Minh <minhquangbui99@xxxxxxxxx> Date: Wed Apr 24 21:44:23 2024 +0700 octeontx2-af: avoid off-by-one read from userspace [ Upstream commit f299ee709fb45036454ca11e90cb2810fe771878 ] We try to access count + 1 byte from userspace with memdup_user(buffer, count + 1). However, the userspace only provides buffer of count bytes and only these count bytes are verified to be okay to access. To ensure the copied buffer is NUL terminated, we use memdup_user_nul instead. Fixes: 3a2eb515d136 ("octeontx2-af: Fix an off by one in rvu_dbg_qsize_write()") Signed-off-by: Bui Quang Minh <minhquangbui99@xxxxxxxxx> Link: https://lore.kernel.org/r/20240424-fix-oob-read-v2-6-f1f1b53a10f4@xxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c b/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c index 4dddf6ec3be87..e201827529513 100644 --- a/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c +++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c @@ -559,12 +559,10 @@ static ssize_t rvu_dbg_qsize_write(struct file *filp, u16 pcifunc; int ret, lf; - cmd_buf = memdup_user(buffer, count + 1); + cmd_buf = memdup_user_nul(buffer, count); if (IS_ERR(cmd_buf)) return -ENOMEM; - cmd_buf[count] = '\0'; - cmd_buf_tmp = strchr(cmd_buf, '\n'); if (cmd_buf_tmp) { *cmd_buf_tmp = '\0';