From 0a0285cee11c7dcc2657bcd456e469958a5009e7 Mon Sep 17 00:00:00 2001 From: Bui Quang Minh Date: Wed, 24 Apr 2024 21:44:23 +0700 Subject: [PATCH] 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 Link: https://lore.kernel.org/r/20240424-fix-oob-read-v2-6-f1f1b53a10f4@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- 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 d30e84803481..feca86e429df 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';