On 5/23/23 19:38, Markus Elfring wrote:
From: Markus Elfring <elfr...@users.sourceforge.net>
Date: Tue, 23 May 2023 14:32:39 +0200
The return value was overlooked from a call of
the function “fb_alloc_cmap”.
* Thus use a corresponding error check.
* Add two jump targets so that a bit of exception handling
can be better reused at the end of this function.
Reported-by: Helge Deller <del...@gmx.de>
Link:
https://lore.kernel.org/dri-devel/069f2f78-01f3-9476-d860-2b695c122...@gmx.de/
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Fixes: c75f5a550610 ("fbdev: imsttfb: Fix use after free bug in imsttfb_probe")
Signed-off-by: Markus Elfring <elfr...@users.sourceforge.net>
---
drivers/video/fbdev/imsttfb.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/drivers/video/fbdev/imsttfb.c b/drivers/video/fbdev/imsttfb.c
index 975dd682fae4..d3532def4707 100644
--- a/drivers/video/fbdev/imsttfb.c
+++ b/drivers/video/fbdev/imsttfb.c
@@ -1351,6 +1351,7 @@ static int init_imstt(struct fb_info *info)
{
struct imstt_par *par = info->par;
__u32 i, tmp, *ip, *end;
+ int ret;
tmp = read_reg_le32(par->dc_regs, PRC);
if (par->ramdac == IBM)
@@ -1419,8 +1420,7 @@ static int init_imstt(struct fb_info *info)
if ((info->var.xres * info->var.yres) * (info->var.bits_per_pixel >> 3) >
info->fix.smem_len
|| !(compute_imstt_regvals(par, info->var.xres, info->var.yres))) {
printk("imsttfb: %ux%ux%u not supported\n", info->var.xres,
info->var.yres, info->var.bits_per_pixel);
- framebuffer_release(info);
- return -ENODEV;
+ goto e_nodev;
}
sprintf(info->fix.id, "IMS TT (%s)", par->ramdac == IBM ? "IBM" :
"TVP");
@@ -1452,17 +1452,25 @@ static int init_imstt(struct fb_info *info)
FBINFO_HWACCEL_FILLRECT |
FBINFO_HWACCEL_YPAN;
- fb_alloc_cmap(&info->cmap, 0, 0);
+ ret = fb_alloc_cmap(&info->cmap, 0, 0);
+ if (ret)
+ goto release_framebuffer;
if (register_framebuffer(info) < 0) {
- framebuffer_release(info);
- return -ENODEV;
+ fb_dealloc_cmap(&info->cmap);
+ goto e_nodev;
}
tmp = (read_reg_le32(par->dc_regs, SSTATUS) & 0x0f00) >> 8;
fb_info(info, "%s frame buffer; %uMB vram; chip version %u\n",
info->fix.id, info->fix.smem_len >> 20, tmp);
return 0;
+
+e_nodev:
+ ret = -ENODEV;
I think the return value isn't checked at all, so you could
simply return below "-ENODEV" for all cases (instead of "return ret").
Then you don't need the e_nodev label and can simplify the flow.
Helge
+release_framebuffer:
+ framebuffer_release(info);
+ return ret;
}
static int imsttfb_probe(struct pci_dev *pdev, const struct pci_device_id
*ent)
--
2.40.1
