From: Dan Carpenter dan.carpenter@oracle.com
[ Upstream commit 40ec787e1adf302c11668d4cc69838f4d584187d ]
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 dan.carpenter@oracle.com Link: https://lore.kernel.org/r/YthIKn+TfZSZMEcM@kili Reviewed-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 2db7113383fd..89d9fca02fe9 100644 --- a/drivers/platform/olpc/olpc-ec.c +++ b/drivers/platform/olpc/olpc-ec.c @@ -265,7 +265,7 @@ 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);