In case of allocation failures, all code paths was jumping to this code:
err: kfree(fbi); kfree(var); kfree(fbops);
return r;
Since all 3 pointers placed on stack and don't initialized, they will be filled with some random values, which leads to deferencing random pointers in kfree(). Fix it by rewriting error handling path.
Fixes: 897044e99e43 ("OMAP: DSS2: OMAPFB: Reduce stack usage") Signed-off-by: Pavel Skripkin paskripkin@gmail.com --- .../video/fbdev/omap2/omapfb/omapfb-main.c | 21 +++++++++---------- 1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/drivers/video/fbdev/omap2/omapfb/omapfb-main.c b/drivers/video/fbdev/omap2/omapfb/omapfb-main.c index a3decc7fadde..6a302138ebeb 100644 --- a/drivers/video/fbdev/omap2/omapfb/omapfb-main.c +++ b/drivers/video/fbdev/omap2/omapfb/omapfb-main.c @@ -2025,21 +2025,19 @@ static int omapfb_mode_to_timings(const char *mode_str, fbops = NULL;
fbi = kzalloc(sizeof(*fbi), GFP_KERNEL); - if (fbi == NULL) { - r = -ENOMEM; - goto err; - } + if (fbi == NULL) + return -ENOMEM;
var = kzalloc(sizeof(*var), GFP_KERNEL); if (var == NULL) { r = -ENOMEM; - goto err; + goto err_var; }
fbops = kzalloc(sizeof(*fbops), GFP_KERNEL); if (fbops == NULL) { r = -ENOMEM; - goto err; + goto err_fbops; }
fbi->fbops = fbops; @@ -2047,7 +2045,7 @@ static int omapfb_mode_to_timings(const char *mode_str, r = fb_find_mode(var, fbi, mode_str, NULL, 0, NULL, 24); if (r == 0) { r = -EINVAL; - goto err; + goto err_find; }
if (display->driver->get_timings) { @@ -2088,11 +2086,12 @@ static int omapfb_mode_to_timings(const char *mode_str,
r = 0;
-err: - kfree(fbi); - kfree(var); +err_find: kfree(fbops); - +err_fbops: + kfree(var); +err_var: + kfree(fbi); return r; }