[PATCH AUTOSEL 5.5 296/542] drm: remove the newline for CRC source name.

[Sasha Levin]

From: Dingchen Zhang <dingchen.zhang@xxxxxxx>

[ Upstream commit 72a848f5c46bab4c921edc9cbffd1ab273b2be17 ]

userspace may transfer a newline, and this terminating newline
is replaced by a '\0' to avoid followup issues.

'len-1' is the index to replace the newline of CRC source name.

v3: typo fix (Sam)

v2: update patch subject, body and format. (Sam)

Cc: Leo Li <sunpeng.li@xxxxxxx>
Cc: Harry Wentland <Harry.Wentland@xxxxxxx>
Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
Signed-off-by: Dingchen Zhang <dingchen.zhang@xxxxxxx>
Reviewed-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20190610134751.14356-1-dingchen.zhang@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/gpu/drm/drm_debugfs_crc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_debugfs_crc.c b/drivers/gpu/drm/drm_debugfs_crc.c
index ca3c55c6b8155..2ece2957da1af 100644
--- a/drivers/gpu/drm/drm_debugfs_crc.c
+++ b/drivers/gpu/drm/drm_debugfs_crc.c
@@ -140,8 +140,8 @@ static ssize_t crc_control_write(struct file *file, const char __user *ubuf,
 	if (IS_ERR(source))
 		return PTR_ERR(source);
 
-	if (source[len] == '\n')
-		source[len] = '\0';
+	if (source[len - 1] == '\n')
+		source[len - 1] = '\0';
 
 	ret = crtc->funcs->verify_crc_source(crtc, source, &values_cnt);
 	if (ret)
-- 
2.20.1