CVE-2026-74452: drm/panthor: reject firmware sections with oversized data

CVE-2026-74452: drm/panthor: reject firmware sections with oversized data

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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

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

drm/panthor: reject firmware sections with oversized data

In panthor_fw_load_section_entry(), the data size to copy is calculated
without validating it against the allocated section_size:

    section->data.size = hdr.data.end - hdr.data.start;

If a crafted firmware sets data.size larger than the allocated memory,
this could cause a heap buffer overflow in panthor_fw_init_section_mem()

    memcpy(section->mem->kmap, section->data.buf, section->data.size);

Additionally, if the section->data.size exceeds the BO size, could this
memset underflow the size calculation, leading to a massive out-of-bounds
zeroing of kernel memory?

    memset(section->mem->kmap + section->data.size, 0,
           panthor_kernel_bo_size(section->mem) - section->data.size);

Reject section entries whose initial data is larger than the section size.

The Linux kernel CVE team has assigned CVE-2026-74452 to this issue.


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

	Issue introduced in 6.10 with commit 2718d91816eeed03c09c8abe872e45f59078768c and fixed in 6.12.103 with commit 0e57165ca025a67d8dfd17efd2765fdd4925fdab
	Issue introduced in 6.10 with commit 2718d91816eeed03c09c8abe872e45f59078768c and fixed in 6.18.44 with commit 2a761b9be5863e1d26a584f0c2d1e114a684ed9a
	Issue introduced in 6.10 with commit 2718d91816eeed03c09c8abe872e45f59078768c and fixed in 7.1.8 with commit 7f4674d986c15c74327cb6ac6e2e2afecf061e04
	Issue introduced in 6.10 with commit 2718d91816eeed03c09c8abe872e45f59078768c and fixed in 7.2-rc6 with commit a3caaa06809248b996254be5b47e10804a3494e2

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-2026-74452
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/gpu/drm/panthor/panthor_fw.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/0e57165ca025a67d8dfd17efd2765fdd4925fdab
	https://git.kernel.org/stable/c/2a761b9be5863e1d26a584f0c2d1e114a684ed9a
	https://git.kernel.org/stable/c/7f4674d986c15c74327cb6ac6e2e2afecf061e04
	https://git.kernel.org/stable/c/a3caaa06809248b996254be5b47e10804a3494e2