CVE-2023-52483: linux kernel Use-After-Free — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: mctp: perform route lookups under a RCU read-side lock Our current route lookups (mctp_route_lookup and mctp_route_lookup_null) traverse the net's route list without the RCU read lock held. This means the route lookup is subject to preemption, resulting in an potential grace period expiry, and so an eventual kfree() while we still have the route pointer. Add the proper read-side critical section locks around the route lookups, preventing premption and a possible parallel kfree. The remaining net->mctp.routes accesses are already under a rcu_read_lock, or protected by the RTNL for updates. Based on an analysis from Sili Luo <[email protected]>, where introducing a delay in the route lookup could cause a UAF on simultaneous sendmsg() and route deletion.

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.15 — 5.15.137
linux	linux_kernel	5.16 — 6.1.59
linux	linux_kernel	6.2 — 6.5.8
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/1db0724a01b558feb1ecae551782add1951a114a https://git.kernel.org/stable/c/2405f64a95a7a094eb24cba9bcfaffd1ea264de4 https://git.kernel.org/stable/c/5093bbfc10ab6636b32728e35813cbd79feb063c https://git.kernel.org/stable/c/6c52b12159049046483fdb0c411a0a1869c41a67 https://git.kernel.org/stable/c/1db0724a01b558feb1ecae551782add1951a114a https://git.kernel.org/stable/c/2405f64a95a7a094eb24cba9bcfaffd1ea264de4 https://git.kernel.org/stable/c/5093bbfc10ab6636b32728e35813cbd79feb063c https://git.kernel.org/stable/c/6c52b12159049046483fdb0c411a0a1869c41a67

Frequently Asked Questions

What is CVE-2023-52483? +

In the Linux kernel, the following vulnerability has been resolved: mctp: perform route lookups under a RCU read-side lock Our current route lookups (mctp_route_lookup and mctp_route_lookup_null) traverse the net's route list without the RCU read lock held. This means the route lookup is subject to preemption, resulting in an potential grace period expiry, and so an eventual kfree() while we still have the route pointer. Add the proper read-side critical section locks around the route lookups, preventing premption and a possible parallel kfree. The remaining net->mctp.routes accesses are already under a rcu_read_lock, or protected by the RTNL for updates. Based on an analysis from Sili Luo <[email protected]>, where introducing a delay in the route lookup could cause a UAF on simultaneous sendmsg() and route deletion. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2023-52483? +

CVE-2023-52483 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2023-52483? +

CVE-2023-52483 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2023-52483? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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