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CVE-2024-53096

mm: resolve faulty mmap_region() error path behaviour

Summary

mm: resolve faulty mmap_region() error path behaviour

Original description

The description as published by the source.

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

mm: resolve faulty mmap_region() error path behaviour

The mmap_region() function is somewhat terrifying, with spaghetti-like
control flow and numerous means by which issues can arise and incomplete
state, memory leaks and other unpleasantness can occur.

A large amount of the complexity arises from trying to handle errors late
in the process of mapping a VMA, which forms the basis of recently
observed issues with resource leaks and observable inconsistent state.

Taking advantage of previous patches in this series we move a number of
checks earlier in the code, simplifying things by moving the core of the
logic into a static internal function __mmap_region().

Doing this allows us to perform a number of checks up front before we do
any real work, and allows us to unwind the writable unmap check
unconditionally as required and to perform a CONFIG_DEBUG_VM_MAPLE_TREE
validation unconditionally also.

We move a number of things here:

  1. We preallocate memory for the iterator before we call the file-backed
    memory hook, allowing us to exit early and avoid having to perform
    complicated and error-prone close/free logic. We carefully free
    iterator state on both success and error paths.

  2. The enclosing mmap_region() function handles the mapping_map_writable()
    logic early. Previously the logic had the mapping_map_writable() at the
    point of mapping a newly allocated file-backed VMA, and a matching…

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

Affected packages

Linux Kernel
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.10.231"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.174"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.119"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.1.0"},{"fixed":"6.6.63"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

References

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