CVE-2022-39842
An issue was discovered in the Linux kernel before 5.19. In pxa3xx_gcu_write in drivers/video/fbdev/pxa3xx-gcu.c, the count parameter has a type conflict of size_t versus int, causing an integer overflow and bypassing the size check. After that, because it is used as the third argument to copy_from_user(), a heap overflow may occur. NOTE: the original discoverer disputes that the overflow can actually happen.
02 / AFFECTED SOFTWARE
Affected packages
1 explicit affected versions
735 explicit affected versions
04 / EVIDENCE
Source records
In pxa3xx_gcu_write of pxa3xx-gcu.c, there is a possible out of bounds write due to an integer overflow. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
An issue was discovered in the Linux kernel before 5.19. In pxa3xx_gcu_write in drivers/video/fbdev/pxa3xx-gcu.c, the count parameter has a type conflict of size_t versus int, causing an integer overflow and bypassing the size check. After that, because it is used as the third argument to copy_from_user(), a heap overflow may occur. NOTE: the original discoverer disputes that the overflow can actually happen.
05 / REFERENCES
Further evidence
- https://android.googlesource.com/kernel/common/+/d75ef462c3dbd5bb52313e32d545c8be7f79049d
- https://source.android.com/security/bulletin/2023-02-01
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.19
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/39xxx/CVE-2022-39842.json
- https://github.com/torvalds/linux/commit/a09d2d00af53b43c6f11e6ab3cb58443c2cac8a7
- https://lists.debian.org/debian-lts-announce/2022/10/msg00000.html
- https://lists.debian.org/debian-lts-announce/2022/11/msg00001.html
- https://lore.kernel.org/all/YylaC1wHHyLw22D3%40kadam/T/
- https://nvd.nist.gov/vuln/detail/CVE-2022-39842
- https://www.debian.org/security/2022/dsa-5257