CVE-2021-47248

MEDIUM
Published May 21, 2024 Modified Apr 30, 2025 CWE-362

Description

In the Linux kernel, the following vulnerability has been resolved: udp: fix race between close() and udp_abort() Kaustubh reported and diagnosed a panic in udp_lib_lookup(). The root cause is udp_abort() racing with close(). Both racing functions acquire the socket lock, but udp{v6}_destroy_sock() release it before performing destructive actions. We can't easily extend the socket lock scope to avoid the race, instead use the SOCK_DEAD flag to prevent udp_abort from doing any action when the critical race happens. Diagnosed-and-tested-by: Kaustubh Pandey <[email protected]>

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CVSS v3.1 Score

4.7
MEDIUM
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-362 CWE-362

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel

References

Advisories & Patches

https://git.kernel.org/stable/c/2f73448041bd0682d4b552cfd314ace66107f1ad https://git.kernel.org/stable/c/5a88477c1c85e4baa51e91f2d40f2166235daa56 https://git.kernel.org/stable/c/65310b0aff86980a011c7c7bfa487a333d4ca241 https://git.kernel.org/stable/c/8729ec8a2238152a4afc212a331a6cd2c61aeeac https://git.kernel.org/stable/c/a0882f68f54f7a8b6308261acee9bd4faab5a69e https://git.kernel.org/stable/c/a8b897c7bcd47f4147d066e22cc01d1026d7640e https://git.kernel.org/stable/c/e3c36c773aed0fef8b1d3d555b43393ec564400f https://git.kernel.org/stable/c/2f73448041bd0682d4b552cfd314ace66107f1ad https://git.kernel.org/stable/c/5a88477c1c85e4baa51e91f2d40f2166235daa56 https://git.kernel.org/stable/c/65310b0aff86980a011c7c7bfa487a333d4ca241 https://git.kernel.org/stable/c/8729ec8a2238152a4afc212a331a6cd2c61aeeac https://git.kernel.org/stable/c/a0882f68f54f7a8b6308261acee9bd4faab5a69e https://git.kernel.org/stable/c/a8b897c7bcd47f4147d066e22cc01d1026d7640e https://git.kernel.org/stable/c/e3c36c773aed0fef8b1d3d555b43393ec564400f

Frequently Asked Questions

What is CVE-2021-47248? +
In the Linux kernel, the following vulnerability has been resolved: udp: fix race between close() and udp_abort() Kaustubh reported and diagnosed a panic in udp_lib_lookup(). The root cause is udp_abort() racing with close(). Both racing functions acquire the socket lock, but udp{v6}_destroy_sock() release it before performing destructive actions. We can't easily extend the socket lock scope to avoid the race, instead use the SOCK_DEAD flag to prevent udp_abort from doing any action when the critical race happens. Diagnosed-and-tested-by: Kaustubh Pandey <[email protected]> It has a CVSS v3.1 base score of 4.7 (MEDIUM).
How severe is CVE-2021-47248? +
CVE-2021-47248 has a CVSS v3.1 score of 4.7 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.
What products are affected by CVE-2021-47248? +
CVE-2021-47248 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-2021-47248? +
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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