CVE-2024-43854

In the Linux kernel, the following vulnerability has been resolved:

block: initialize integrity buffer to zero before writing it to media

Metadata added by bio_integrity_prep is using plain kmalloc, which leads to random kernel memory being written media. For PI metadata this is limited to the app tag that isnt used by kernel generated metadata, but for non-PI metadata the entire buffer leaks kernel memory.

Fix this by adding the __GFP_ZERO flag to allocations for writes.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

• https://git.kernel.org/stable/c/129f95948a96105c1fad8e612c9097763e88ac5f
• https://git.kernel.org/stable/c/23a19655fb56f241e592041156dfb1c6d04da644
• https://git.kernel.org/stable/c/3fd11fe4f20756b4c0847f755a64cd96f8c6a005
• https://git.kernel.org/stable/c/899ee2c3829c5ac14bfc7d3c4a5846c0b709b78f
• https://git.kernel.org/stable/c/9f4af4cf08f9a0329ade3d938f55d2220c40d0a6
• https://git.kernel.org/stable/c/cf6b45ea7a8df0f61bded1dc4a8561ac6ad143d2
• https://git.kernel.org/stable/c/d418313bd8f55c079a7da12651951b489a638ac1
• https://git.kernel.org/stable/c/ebc0e91ba76dc6544fff9f5b66408b1982806a00