diff options
| author | Zheng Wang <zyytlz.wz@163.com> | 2023-04-27 11:08:41 +0800 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2023-05-11 22:58:59 +0200 |
| commit | c75f5a55061091030a13fef71b9995b89bc86213 (patch) | |
| tree | 7a8abedd4254f120f6d2b1178d8c96e01bb6f3e4 /drivers/video | |
| parent | 6208890495ded5429424b0335c7fd2d47fdffb83 (diff) | |
| download | lwn-c75f5a55061091030a13fef71b9995b89bc86213.tar.gz lwn-c75f5a55061091030a13fef71b9995b89bc86213.zip | |
fbdev: imsttfb: Fix use after free bug in imsttfb_probe
A use-after-free bug may occur if init_imstt invokes framebuffer_release
and free the info ptr. The caller, imsttfb_probe didn't notice that and
still keep the ptr as private data in pdev.
If we remove the driver which will call imsttfb_remove to make cleanup,
UAF happens.
Fix it by return error code if bad case happens in init_imstt.
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/fbdev/imsttfb.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/video/fbdev/imsttfb.c b/drivers/video/fbdev/imsttfb.c index bea45647184e..975dd682fae4 100644 --- a/drivers/video/fbdev/imsttfb.c +++ b/drivers/video/fbdev/imsttfb.c @@ -1347,7 +1347,7 @@ static const struct fb_ops imsttfb_ops = { .fb_ioctl = imsttfb_ioctl, }; -static void init_imstt(struct fb_info *info) +static int init_imstt(struct fb_info *info) { struct imstt_par *par = info->par; __u32 i, tmp, *ip, *end; @@ -1420,7 +1420,7 @@ static void init_imstt(struct fb_info *info) || !(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; + return -ENODEV; } sprintf(info->fix.id, "IMS TT (%s)", par->ramdac == IBM ? "IBM" : "TVP"); @@ -1456,12 +1456,13 @@ static void init_imstt(struct fb_info *info) if (register_framebuffer(info) < 0) { framebuffer_release(info); - return; + return -ENODEV; } 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; } static int imsttfb_probe(struct pci_dev *pdev, const struct pci_device_id *ent) @@ -1529,10 +1530,10 @@ static int imsttfb_probe(struct pci_dev *pdev, const struct pci_device_id *ent) if (!par->cmap_regs) goto error; info->pseudo_palette = par->palette; - init_imstt(info); - - pci_set_drvdata(pdev, info); - return 0; + ret = init_imstt(info); + if (!ret) + pci_set_drvdata(pdev, info); + return ret; error: if (par->dc_regs) |