CVE-2021-47291: linux kernel Out-of-bounds Read — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix another slab-out-of-bounds in fib6_nh_flush_exceptions While running the self-tests on a KASAN enabled kernel, I observed a slab-out-of-bounds splat very similar to the one reported in commit 821bbf79fe46 ("ipv6: Fix KASAN: slab-out-of-bounds Read in fib6_nh_flush_exceptions"). We additionally need to take care of fib6_metrics initialization failure when the caller provides an nh. The fix is similar, explicitly free the route instead of calling fib6_info_release on a half-initialized object.

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CVSS v3.1 Score

7.1

HIGH

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

Weakness Type (CWE)

CWE-125 Out-of-bounds Read

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.3 — 5.4.136
linux	linux_kernel	5.5 — 5.10.54
linux	linux_kernel	5.11 — 5.13.6
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/115784bcccf135c3a3548098153413d76f16aae0 https://git.kernel.org/stable/c/830251361425c5be044db4d826aaf304ea3d14c6 https://git.kernel.org/stable/c/8fb4792f091e608a0a1d353dfdf07ef55a719db5 https://git.kernel.org/stable/c/ce8fafb68051fba52546f8bbe8621f7641683680 https://git.kernel.org/stable/c/115784bcccf135c3a3548098153413d76f16aae0 https://git.kernel.org/stable/c/830251361425c5be044db4d826aaf304ea3d14c6 https://git.kernel.org/stable/c/8fb4792f091e608a0a1d353dfdf07ef55a719db5 https://git.kernel.org/stable/c/ce8fafb68051fba52546f8bbe8621f7641683680

Frequently Asked Questions

What is CVE-2021-47291? +

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix another slab-out-of-bounds in fib6_nh_flush_exceptions While running the self-tests on a KASAN enabled kernel, I observed a slab-out-of-bounds splat very similar to the one reported in commit 821bbf79fe46 ("ipv6: Fix KASAN: slab-out-of-bounds Read in fib6_nh_flush_exceptions"). We additionally need to take care of fib6_metrics initialization failure when the caller provides an nh. The fix is similar, explicitly free the route instead of calling fib6_info_release on a half-initialized object. It has a CVSS v3.1 base score of 7.1 (HIGH).

How severe is CVE-2021-47291? +

CVE-2021-47291 has a CVSS v3.1 score of 7.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2021-47291? +

CVE-2021-47291 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-2021-47291? +

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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