[PATCH] video: fbdev: neofb: fix memory leak in neo_scan_monitor()

neofb_probe() calls neo_scan_monitor() that can successfully allocate a
memory for info->monspecs.modedb and proceed to case 0x03. There it does
not free the memory and returns -1. neofb_probe() goes to label
err_scan_monitor, thus, it does not free this memory through calling
fb_destroy_modedb() as well. We can not go to label err_init_hw since
neo_scan_monitor() can fail during memory allocation. So, the patch frees
the memory directly for case 0x03.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Evgeny Novikov <redacted>
---
 drivers/video/fbdev/neofb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/video/fbdev/neofb.c b/drivers/video/fbdev/neofb.c
index f5a676bfd67a..09a20d4ab35f 100644
--- a/drivers/video/fbdev/neofb.c
+++ b/drivers/video/fbdev/neofb.c

@@ -1819,6 +1819,7 @@ static int neo_scan_monitor(struct fb_info *info)
 #else
 		printk(KERN_ERR
 		       "neofb: Only 640x480, 800x600/480 and 1024x768 panels are currently supported\n");
+		kfree(info->monspecs.modedb);
 		return -1;
 #endif
 	default:

-- 
2.16.4

On 6/30/20 9:54 PM, Evgeny Novikov wrote:

neofb_probe() calls neo_scan_monitor() that can successfully allocate a
memory for info->monspecs.modedb and proceed to case 0x03. There it does
not free the memory and returns -1. neofb_probe() goes to label
err_scan_monitor, thus, it does not free this memory through calling
fb_destroy_modedb() as well. We can not go to label err_init_hw since
neo_scan_monitor() can fail during memory allocation. So, the patch frees
the memory directly for case 0x03.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Evgeny Novikov <redacted>

Applied to drm-misc-next tree, thanks.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics