From 40ec787e1adf302c11668d4cc69838f4d584187d Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 20 Jul 2022 21:23:38 +0300 Subject: [PATCH] platform/olpc: Fix uninitialized data in debugfs write The call to: size = simple_write_to_buffer(cmdbuf, sizeof(cmdbuf), ppos, buf, size); will succeed if at least one byte is written to the "cmdbuf" buffer. The "*ppos" value controls which byte is written. Another problem is that this code does not check for errors so it's possible for the entire buffer to be uninitialized. Inintialize the struct to zero to prevent reading uninitialized stack data. Debugfs is normally only writable by root so the impact of this bug is very minimal. Fixes: 6cca83d498bd ("Platform: OLPC: move debugfs support from x86 EC driver") Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/YthIKn+TfZSZMEcM@kili Reviewed-by: Hans de Goede Signed-off-by: Hans de Goede --- drivers/platform/olpc/olpc-ec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/platform/olpc/olpc-ec.c b/drivers/platform/olpc/olpc-ec.c index 4ff5c3a12991..921520475ff6 100644 --- a/drivers/platform/olpc/olpc-ec.c +++ b/drivers/platform/olpc/olpc-ec.c @@ -264,7 +264,7 @@ static ssize_t ec_dbgfs_cmd_write(struct file *file, const char __user *buf, int i, m; unsigned char ec_cmd[EC_MAX_CMD_ARGS]; unsigned int ec_cmd_int[EC_MAX_CMD_ARGS]; - char cmdbuf[64]; + char cmdbuf[64] = ""; int ec_cmd_bytes; mutex_lock(&ec_dbgfs_lock); -- 2.11.0