From 1ce23d5f20eec9ef48c2d40ed7831ee8ab9733c4 Mon Sep 17 00:00:00 2001 From: Kamal Heib Date: Fri, 7 Jun 2024 20:10:25 -0400 Subject: [PATCH] octeontx2-af: avoid off-by-one read from userspace JIRA: https://issues.redhat.com/browse/RHEL-39873 CVE: CVE-2024-36957 commit f299ee709fb45036454ca11e90cb2810fe771878 Author: Bui Quang Minh Date: Wed Apr 24 21:44:23 2024 +0700 octeontx2-af: avoid off-by-one read from userspace 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 Link: https://lore.kernel.org/r/20240424-fix-oob-read-v2-6-f1f1b53a10f4@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Kamal Heib --- drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c b/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c index 9533b1d92960..803039bef684 100644 --- a/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c +++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c @@ -999,12 +999,10 @@ 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';