CVE-2026-46314
drm/v3d: Reject empty multisync extension to prevent infinite loop
Description
In the Linux kernel, the following vulnerability has been resolved: drm/v3d: Reject empty multisync extension to prevent infinite loop v3d_get_extensions() walks a userspace-provided singly-linked list of ioctl extensions without any bound on the chain length. A local user can craft a self-referential extension (ext->next == &ext) with zero in_sync_count and out_sync_count, which bypasses the existing duplicate- extension guard: if (se->in_sync_count || se->out_sync_count) return -EINVAL; The guard never fires because v3d_get_multisync_post_deps() returns immediately when count is zero, leaving both fields at zero on every iteration. The result is an infinite loop in kernel context, blocking the calling thread and pegging a CPU core indefinitely. Fix this by rejecting a multisync extension where both in_sync_count and out_sync_count are zero in v3d_get_multisync_submit_deps(). An empty multisync carries no synchronization information and serves no useful purpose, so returning -EINVAL for such an extension is the correct defense against this attack vector.
INFO
Published Date :
June 8, 2026, 5:16 p.m.
Last Modified :
June 8, 2026, 5:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-46314
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Apply kernel patches that reject zero-count multisync extensions.
- Update the Linux kernel to a patched version.
- Reject multisync extensions where in_sync_count and out_sync_count are zero.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-46314.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-46314 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-46314
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-46314 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-46314 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 08, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: drm/v3d: Reject empty multisync extension to prevent infinite loop v3d_get_extensions() walks a userspace-provided singly-linked list of ioctl extensions without any bound on the chain length. A local user can craft a self-referential extension (ext->next == &ext) with zero in_sync_count and out_sync_count, which bypasses the existing duplicate- extension guard: if (se->in_sync_count || se->out_sync_count) return -EINVAL; The guard never fires because v3d_get_multisync_post_deps() returns immediately when count is zero, leaving both fields at zero on every iteration. The result is an infinite loop in kernel context, blocking the calling thread and pegging a CPU core indefinitely. Fix this by rejecting a multisync extension where both in_sync_count and out_sync_count are zero in v3d_get_multisync_submit_deps(). An empty multisync carries no synchronization information and serves no useful purpose, so returning -EINVAL for such an extension is the correct defense against this attack vector. Added Reference https://git.kernel.org/stable/c/4fa42a249e8cd6ed17aea04e5695b6e9001f2433 Added Reference https://git.kernel.org/stable/c/9c5164781cb388d219d8f49fa0f0b04cf86ad544 Added Reference https://git.kernel.org/stable/c/fb44d589bf3148e13452185a6e772a7efbf2d684