Vulnerabilities > CVE-2024-35827 - Integer Overflow or Wraparound vulnerability in Linux Kernel
Summary
In the Linux kernel, the following vulnerability has been resolved: io_uring/net: fix overflow check in io_recvmsg_mshot_prep() The "controllen" variable is type size_t (unsigned long). Casting it to int could lead to an integer underflow. The check_add_overflow() function considers the type of the destination which is type int. If we add two positive values and the result cannot fit in an integer then that's counted as an overflow. However, if we cast "controllen" to an int and it turns negative, then negative values *can* fit into an int type so there is no overflow. Good: 100 + (unsigned long)-4 = 96 <-- overflow Bad: 100 + (int)-4 = 96 <-- no overflow I deleted the cast of the sizeof() as well. That's not a bug but the cast is unnecessary.
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://git.kernel.org/stable/c/0c8c74bb59e7d77554016efc34c2d10376985e5e
- https://git.kernel.org/stable/c/0c8c74bb59e7d77554016efc34c2d10376985e5e
- https://git.kernel.org/stable/c/59a534690ecc3af72c6ab121aeac1237a4adae66
- https://git.kernel.org/stable/c/59a534690ecc3af72c6ab121aeac1237a4adae66
- https://git.kernel.org/stable/c/868ec868616438df487b9e2baa5a99f8662cc47c
- https://git.kernel.org/stable/c/868ec868616438df487b9e2baa5a99f8662cc47c
- https://git.kernel.org/stable/c/8ede3db5061bb1fe28e2c9683329aafa89d2b1b4
- https://git.kernel.org/stable/c/8ede3db5061bb1fe28e2c9683329aafa89d2b1b4
- https://git.kernel.org/stable/c/b6563ad0d599110bd5cf8f56c47d279c3ed796fe
- https://git.kernel.org/stable/c/b6563ad0d599110bd5cf8f56c47d279c3ed796fe