CVE-2026-74403: crypto: ccp - Check for page allocation failure correctly in TIO

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

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

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

crypto: ccp - Check for page allocation failure correctly in TIO

Sashiko notes:

> if __snp_alloc_firmware_pages() returns NULL under memory pressure, is it
> safe to pass it directly to page_address()?
>
> On architectures without HASHED_PAGE_VIRTUAL, page_address(NULL) might
> compute a deterministic but invalid, non-zero virtual address. The
> subsequent if (tio_status) check would then evaluate to true, and
> sev_tsm_init_locked() would dereference the invalid pointer.

Indeed, page_address(NULL) will return non-NULL garbage here. Fix this by
checking the page allocation itself for NULL, not the resulting virtual
address.

The Linux kernel CVE team has assigned CVE-2026-74403 to this issue.


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

	Issue introduced in 6.19 with commit 4be423572da1f4c11f45168e3fafda870ddac9f8 and fixed in 7.1.5 with commit 17e1aae19a06d9f6da4b46d54fa2aeab77ec0c69
	Issue introduced in 6.19 with commit 4be423572da1f4c11f45168e3fafda870ddac9f8 and fixed in 7.2-rc1 with commit a8d5370eef00eca132a292b1901c9914c817e385

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-2026-74403
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/crypto/ccp/sev-dev.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/17e1aae19a06d9f6da4b46d54fa2aeab77ec0c69
	https://git.kernel.org/stable/c/a8d5370eef00eca132a292b1901c9914c817e385