Vulnerabilities > CVE-2024-26883 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in Linux Kernel
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix stackmap overflow check on 32-bit arches The stackmap code relies on roundup_pow_of_two() to compute the number of hash buckets, and contains an overflow check by checking if the resulting value is 0. However, on 32-bit arches, the roundup code itself can overflow by doing a 32-bit left-shift of an unsigned long value, which is undefined behaviour, so it is not guaranteed to truncate neatly. This was triggered by syzbot on the DEVMAP_HASH type, which contains the same check, copied from the hashtab code. The commit in the fixes tag actually attempted to fix this, but the fix did not account for the UB, so the fix only works on CPUs where an overflow does result in a neat truncation to zero, which is not guaranteed. Checking the value before rounding does not have this problem.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Buffer Overflow via Environment Variables This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
- Overflow Buffers Buffer Overflow attacks target improper or missing bounds checking on buffer operations, typically triggered by input injected by an attacker. As a consequence, an attacker is able to write past the boundaries of allocated buffer regions in memory, causing a program crash or potentially redirection of execution as per the attackers' choice.
- Client-side Injection-induced Buffer Overflow This type of attack exploits a buffer overflow vulnerability in targeted client software through injection of malicious content from a custom-built hostile service.
- Filter Failure through Buffer Overflow In this attack, the idea is to cause an active filter to fail by causing an oversized transaction. An attacker may try to feed overly long input strings to the program in an attempt to overwhelm the filter (by causing a buffer overflow) and hoping that the filter does not fail securely (i.e. the user input is let into the system unfiltered).
- MIME Conversion An attacker exploits a weakness in the MIME conversion routine to cause a buffer overflow and gain control over the mail server machine. The MIME system is designed to allow various different information formats to be interpreted and sent via e-mail. Attack points exist when data are converted to MIME compatible format and back.
References
- https://git.kernel.org/stable/c/0971126c8164abe2004b8536b49690a0d6005b0a
- https://git.kernel.org/stable/c/0971126c8164abe2004b8536b49690a0d6005b0a
- https://git.kernel.org/stable/c/15641007df0f0d35fa28742b25c2a7db9dcd6895
- https://git.kernel.org/stable/c/15641007df0f0d35fa28742b25c2a7db9dcd6895
- https://git.kernel.org/stable/c/21e5fa4688e1a4d3db6b72216231b24232f75c1d
- https://git.kernel.org/stable/c/21e5fa4688e1a4d3db6b72216231b24232f75c1d
- https://git.kernel.org/stable/c/43f798b9036491fb014b55dd61c4c5c3193267d0
- https://git.kernel.org/stable/c/43f798b9036491fb014b55dd61c4c5c3193267d0
- https://git.kernel.org/stable/c/7070b274c7866a4c5036f8d54fcaf315c64ac33a
- https://git.kernel.org/stable/c/7070b274c7866a4c5036f8d54fcaf315c64ac33a
- https://git.kernel.org/stable/c/7a4b21250bf79eef26543d35bd390448646c536b
- https://git.kernel.org/stable/c/7a4b21250bf79eef26543d35bd390448646c536b
- https://git.kernel.org/stable/c/ca1f06e72dec41ae4f76e7b1a8a97265447b46ae
- https://git.kernel.org/stable/c/ca1f06e72dec41ae4f76e7b1a8a97265447b46ae
- https://git.kernel.org/stable/c/d0e214acc59145ce25113f617311aa79dda39cb3
- https://git.kernel.org/stable/c/d0e214acc59145ce25113f617311aa79dda39cb3
- https://git.kernel.org/stable/c/f06899582ccee09bd85d0696290e3eaca9aa042d
- https://git.kernel.org/stable/c/f06899582ccee09bd85d0696290e3eaca9aa042d
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html
- https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html