| From e3f91c674c2dacf02ad73834d21f5d6ecbe9f9e6 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Wed, 20 Jul 2022 21:23:38 +0300 |
| Subject: platform/olpc: Fix uninitialized data in debugfs write |
| |
| 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); |
| -- |
| 2.35.1 |
| |
