CVE-2026-64147: pds_core: fix debugfs_lookup dentry leak and error handling

From: Greg Kroah-Hartman <[email protected]>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

pds_core: fix debugfs_lookup dentry leak and error handling

debugfs_lookup() returns a dentry with an elevated reference count that
must be released with dput(). The current code discards the returned
dentry without calling dput(), causing a reference leak on every
firmware reset recovery.

Additionally, when CONFIG_DEBUG_FS is disabled, debugfs_lookup()
returns ERR_PTR(-ENODEV), not NULL. The current check passes for error
pointers and would call dput() on an invalid pointer, causing a crash.

The Linux kernel CVE team has assigned CVE-2026-64147 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.6.16 with commit 2bbf2b1c20f934a054172175ccbabcc01fe69ef6 and fixed in 6.6.142 with commit 60ef1675b652e912f3eb064767af4432393291fd
	Issue introduced in 6.8 with commit bc90fbe0c3182157d2be100a2f6c2edbb1820677 and fixed in 6.12.92 with commit 26e19622c485e53c3fdb299e822068a0542ddf0c
	Issue introduced in 6.8 with commit bc90fbe0c3182157d2be100a2f6c2edbb1820677 and fixed in 6.18.34 with commit 91d13e92b983e6c6d7631012c2e20ae8057de9f2
	Issue introduced in 6.8 with commit bc90fbe0c3182157d2be100a2f6c2edbb1820677 and fixed in 7.0.11 with commit d7f4dd4c8fb380898fef7a77d48fce7ccdb4fc32
	Issue introduced in 6.8 with commit bc90fbe0c3182157d2be100a2f6c2edbb1820677 and fixed in 7.1 with commit dc416e32baaeb620b9809e9e25fc7b30889686e9
	Issue introduced in 6.7.4 with commit 3ffe14c36985e3174933127c9efad82ac8f3fefb

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-64147
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ethernet/amd/pds_core/debugfs.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/60ef1675b652e912f3eb064767af4432393291fd
	https://git.kernel.org/stable/c/26e19622c485e53c3fdb299e822068a0542ddf0c
	https://git.kernel.org/stable/c/91d13e92b983e6c6d7631012c2e20ae8057de9f2
	https://git.kernel.org/stable/c/d7f4dd4c8fb380898fef7a77d48fce7ccdb4fc32
	https://git.kernel.org/stable/c/dc416e32baaeb620b9809e9e25fc7b30889686e9