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| author | Igor Matheus Andrade Torrente <igormtorrente@gmail.com> | 2021-05-03 13:57:06 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-13 17:33:55 +0200 |
| commit | dc13cac4862cc68ec74348a80b6942532b7735fa (patch) | |
| tree | 76b99cc1e200e5de2f07838e2d85b5b46f175836 /drivers/video | |
| parent | 58c0cc2d90f1e37c4eb63ae7f164c83830833f78 (diff) | |
| download | linux-dc13cac4862cc68ec74348a80b6942532b7735fa.tar.gz linux-dc13cac4862cc68ec74348a80b6942532b7735fa.tar.bz2 linux-dc13cac4862cc68ec74348a80b6942532b7735fa.zip | |
video: hgafb: fix potential NULL pointer dereference
The return of ioremap if not checked, and can lead to a NULL to be
assigned to hga_vram. Potentially leading to a NULL pointer
dereference.
The fix adds code to deal with this case in the error label and
changes how the hgafb_probe handles the return of hga_card_detect.
Cc: Ferenc Bakonyi <fero@drama.obuda.kando.hu>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Igor Matheus Andrade Torrente <igormtorrente@gmail.com>
Link: https://lore.kernel.org/r/20210503115736.2104747-40-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/fbdev/hgafb.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/drivers/video/fbdev/hgafb.c b/drivers/video/fbdev/hgafb.c index fca29f219f8b..cc8e62ae93f6 100644 --- a/drivers/video/fbdev/hgafb.c +++ b/drivers/video/fbdev/hgafb.c @@ -285,6 +285,8 @@ static int hga_card_detect(void) hga_vram_len = 0x08000; hga_vram = ioremap(0xb0000, hga_vram_len); + if (!hga_vram) + return -ENOMEM; if (request_region(0x3b0, 12, "hgafb")) release_io_ports = 1; @@ -344,13 +346,18 @@ static int hga_card_detect(void) hga_type_name = "Hercules"; break; } - return 1; + return 0; error: if (release_io_ports) release_region(0x3b0, 12); if (release_io_port) release_region(0x3bf, 1); - return 0; + + iounmap(hga_vram); + + pr_err("hgafb: HGA card not detected.\n"); + + return -EINVAL; } /** @@ -548,13 +555,11 @@ static const struct fb_ops hgafb_ops = { static int hgafb_probe(struct platform_device *pdev) { struct fb_info *info; + int ret; - if (! hga_card_detect()) { - printk(KERN_INFO "hgafb: HGA card not detected.\n"); - if (hga_vram) - iounmap(hga_vram); - return -EINVAL; - } + ret = hga_card_detect(); + if (!ret) + return ret; printk(KERN_INFO "hgafb: %s with %ldK of memory detected.\n", hga_type_name, hga_vram_len/1024); |