Messages in this thread | | | Date | Wed, 24 May 2023 20:20:11 +0200 | Subject | Re: [PATCH 1/4] fbdev: imsttfb: Fix error handling in init_imstt() | From | Helge Deller <> |
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On 5/23/23 19:38, Markus Elfring wrote: > From: Markus Elfring <elfring@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 <deller@gmx.de> > Link: https://lore.kernel.org/dri-devel/069f2f78-01f3-9476-d860-2b695c122649@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 <elfring@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 >
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