[PATCH 5.17 0062/1126] remoteproc: Fix count check in rproc_coredump_write()

Greg Kroah-Hartman
2022-04-05T07:50:24Z

From: Alistair Delva <adelva@google.com>

commit f89672cc3681952f2d06314981a6b45f8b0045d1 upstream.

Check count for 0, to avoid a potential underflow. Make the check the
same as the one in rproc_recovery_write().

Fixes: 3afdc59e4390 ("remoteproc: Add coredump debugfs entry")
Signed-off-by: Alistair Delva <adelva@google.com>
Cc: Rishabh Bhatnagar <rishabhb@codeaurora.org>
Cc: stable@vger.kernel.org
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Sibi Sankar <sibis@codeaurora.org>
Cc: linux-remoteproc@vger.kernel.org
Cc: kernel-team@android.com
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220119232139.1125908-1-adelva@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/remoteproc/remoteproc_debugfs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/remoteproc/remoteproc_debugfs.c
+++ b/drivers/remoteproc/remoteproc_debugfs.c
@@ -76,7 +76,7 @@ static ssize_t rproc_coredump_write(stru
int ret, err = 0;
char buf[20];

- if (count > sizeof(buf))
+ if (count < 1 || count > sizeof(buf))
return -EINVAL;

ret = copy_from_user(buf, user_buf, count);