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[15/99] fbdev/cirrusfb: Duplicate video-mode option string

Message ID 20230306160016.4459-16-tzimmermann@suse.de
State New
Headers show
Series fbdev: Fix memory leak in option parsing | expand

Commit Message

Thomas Zimmermann March 6, 2023, 3:58 p.m. UTC
Assume that the driver does not own the option string or its substrings
and hence duplicate the option string for the video mode. The driver only
parses the option string once as part of module initialization, so use
a static buffer to store the duplicated mode option. Linux automatically
frees the memory upon releasing the module.

Done in preparation of switching the driver to struct option_iter and
constifying the option string.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/video/fbdev/cirrusfb.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)
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Patch

diff --git a/drivers/video/fbdev/cirrusfb.c b/drivers/video/fbdev/cirrusfb.c
index ba45e2147c52..fbf9281a7004 100644
--- a/drivers/video/fbdev/cirrusfb.c
+++ b/drivers/video/fbdev/cirrusfb.c
@@ -2336,10 +2336,20 @@  static int __init cirrusfb_setup(char *options)
 
 		if (!strcmp(this_opt, "noaccel"))
 			noaccel = 1;
-		else if (!strncmp(this_opt, "mode:", 5))
-			mode_option = this_opt + 5;
-		else
-			mode_option = this_opt;
+		else {
+			static char mode_option_buf[256];
+			int ret;
+
+			if (!strncmp(this_opt, "mode:", 5))
+				this_opt += 5;
+
+			ret = snprintf(mode_option_buf, sizeof(mode_option_buf), "%s", this_opt);
+			if (WARN(ret < 0, "cirrusfb: ignoring invalid option, ret=%d\n", ret))
+				continue;
+			if (WARN(ret >= sizeof(mode_option_buf), "cirrusfb: option too long\n"))
+				continue;
+			mode_option = mode_option_buf;
+		}
 	}
 	return 0;
 }