Vulnerabilities > CVE-2022-39842 - Integer Overflow or Wraparound vulnerability in multiple products
Attack vector
LOCAL Attack complexity
LOW Privileges required
LOW Confidentiality impact
NONE Integrity impact
LOW Availability impact
HIGH Summary
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.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Forced Integer Overflow This attack forces an integer variable to go out of range. The integer variable is often used as an offset such as size of memory allocation or similarly. The attacker would typically control the value of such variable and try to get it out of range. For instance the integer in question is incremented past the maximum possible value, it may wrap to become a very small, or negative number, therefore providing a very incorrect value which can lead to unexpected behavior. At worst the attacker can execute arbitrary code.
References
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.19
- https://github.com/torvalds/linux/commit/a09d2d00af53b43c6f11e6ab3cb58443c2cac8a7
- https://lists.debian.org/debian-lts-announce/2022/10/msg00000.html
- https://www.debian.org/security/2022/dsa-5257
- https://lists.debian.org/debian-lts-announce/2022/11/msg00001.html
- https://lore.kernel.org/all/YylaC1wHHyLw22D3%40kadam/T/