CVE-2024-26652

What it actually does

Double free of kernel memory object padev in the pdsc_auxbus_dev_release callback when auxiliary_device_add fails, because a redundant kfree remains in the error path after the release function already frees the allocation.

Why it matters to the business

Unpatched Linux kernel builds may experience memory corruption that leads to crashes or unpredictable behavior on systems using the affected pds_core driver, increasing downtime risk for network-dependent workloads.

How an attack unfolds

An attacker with the ability to induce failure in auxiliary_device_add (for example via resource exhaustion or malformed device registration) can trigger the error path that performs a second kfree on an already-released object, resulting in memory corruption.

How to fix it

Update the Linux kernel to the commit 995f802abff209514ac2ee03b96224237646cec3 or later stable releases that contain the fix removing the redundant kfree in the auxiliary device error path.

How to confirm the fix worked

Confirm the patch is present by inspecting the pdsc_auxbus_dev_release and error-handling functions for removal of the duplicate kfree call; boot the updated kernel and verify auxiliary device registration succeeds without double-free warnings in dmesg.

Typical attack path

1. Cause auxiliary_device_add to return an error for a pds_core auxiliary device
2. Allow the auxiliary_device_uninit path to invoke pdsc_auxbus_dev_release which calls kfree(padev)
3. Execute the leftover kfree(padev) in the original error handler
4. Trigger use of the freed memory to corrupt kernel structures or cause a crash

How to detect it

Review kernel logs for double-free or slab corruption warnings related to padev or pdsc_auxbus_dev_release; examine crash dumps for repeated kfree operations on the same auxiliary device object.

What your security team should do

• Prioritize kernel upgrades containing commit 995f802abff209514ac2ee03b96224237646cec3 on all systems using pds_core
• Monitor vendor advisories for backported fixes in distribution kernels
• Test the updated kernel in a staging environment before broad deployment