Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: tty: Fix out-of-bound vmalloc access in imageblit This issue happens when a userspace program does an ioctl FBIOPUT_VSCREENINFO passing the fb_var_screeninfo struct containing only the fields xres, yres, and bits_per_pixel with values. If this struct is the same as the previous ioctl, the vc_resize() detects it and doesn't call the resize_screen(), leaving the fb_var_screeninfo incomplete. And this leads to the updatescrollmode() calculates a wrong value to fbcon_display->vrows, which makes the real_y() return a wrong value of y, and that value, eventually, causes the imageblit to access an out-of-bound address value. To solve this issue I made the resize_screen() be called even if the screen does not need any resizing, so it will "fix and fill" the fb_var_screeninfo independently.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | < 4.4.286 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/067c694d06040db6f0c65281bb358452ca6d85b9Patch
- https://git.kernel.org/stable/c/3b0c406124719b625b1aba431659f5cdc24a982cPatch
- https://git.kernel.org/stable/c/699d926585daa6ec44be556cdc1ab89e5d54557bPatch
- https://git.kernel.org/stable/c/70aed03b1d5a5df974f456cdc8eedb213c94bb8bPatch
- https://git.kernel.org/stable/c/7e71fcedfda6f7de18f850a6b36e78d78b04476fPatch
- https://git.kernel.org/stable/c/883f7897a25e3ce14a7f274ca4c73f49ac84002aPatch
- https://git.kernel.org/stable/c/8a6a240f52e14356386030d8958ae8b1761d2325Patch
- https://git.kernel.org/stable/c/d570c48dd37dbe8fc6875d4461d01a9554ae2560Patch
- https://git.kernel.org/stable/c/067c694d06040db6f0c65281bb358452ca6d85b9Patch
- https://git.kernel.org/stable/c/3b0c406124719b625b1aba431659f5cdc24a982cPatch
- https://git.kernel.org/stable/c/699d926585daa6ec44be556cdc1ab89e5d54557bPatch
- https://git.kernel.org/stable/c/70aed03b1d5a5df974f456cdc8eedb213c94bb8bPatch
- https://git.kernel.org/stable/c/7e71fcedfda6f7de18f850a6b36e78d78b04476fPatch
- https://git.kernel.org/stable/c/883f7897a25e3ce14a7f274ca4c73f49ac84002aPatch
- https://git.kernel.org/stable/c/8a6a240f52e14356386030d8958ae8b1761d2325Patch
FAQ
What is CVE-2021-47383?
CVE-2021-47383 is a vulnerability with a CVSS score of 7.1 (HIGH). In the Linux kernel, the following vulnerability has been resolved: tty: Fix out-of-bound vmalloc access in imageblit This issue happens when a userspace program does an ioctl FBIOPUT_VSCREENINFO pa...
How severe is CVE-2021-47383?
CVE-2021-47383 has been rated HIGH with a CVSS base score of 7.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-47383?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.