Staging: fbtft: fix memory leak in fbtft_framebuffer_alloc

BugLink: https://bugs.launchpad.net/bugs/1848780

[ Upstream commit 5bdea606 ]

In fbtft_framebuffer_alloc the error handling path should take care of
releasing frame buffer after it is allocated via framebuffer_alloc, too.
Therefore, in two failure cases the goto destination is changed to
address this issue.

Fixes: c296d5f9 ("staging: fbtft: core support")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@gmail.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190930030949.28615-1-navid.emamdoost@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/staging/fbtft/fbtft-core.c

@@ -813,7 +813,7 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
 	if (par->gamma.curves && gamma) {
 		if (fbtft_gamma_parse_str(par,
 			par->gamma.curves, gamma, strlen(gamma)))
-			goto alloc_fail;
+			goto release_framebuf;
 	}
 
 	/* Transmit buffer */
@@ -836,7 +836,7 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
 			txbuf = devm_kzalloc(par->info->device, txbuflen, GFP_KERNEL);
 		}
 		if (!txbuf)
-			goto alloc_fail;
+			goto release_framebuf;
 		par->txbuf.buf = txbuf;
 		par->txbuf.len = txbuflen;
 	}
@@ -872,6 +872,9 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
 
 	return info;
 
+release_framebuf:
+	framebuffer_release(info);
+
 alloc_fail:
 	vfree(vmem);