{"id":"CVE-2026-46314","title":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/v3d: Reject empty multisync extension to prevent infinite loop\n\nv3d_get_extensions() walks a userspace-provided singly-linked list of\nioctl extensions without any b…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/v3d: Reject empty multisync extension to prevent infinite loop\n\nv3d_get_extensions() walks a userspace-provided singly-linked list of\nioctl extensions without any b…","severity":"none","published":"2026-06-08","updated":"2026-07-07","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-46314","references":[{"url":"https://git.kernel.org/stable/c/309abbddeca0c12714721928a819ef45e5710998","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4fa42a249e8cd6ed17aea04e5695b6e9001f2433","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9c5164781cb388d219d8f49fa0f0b04cf86ad544","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fb44d589bf3148e13452185a6e772a7efbf2d684","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00115,"epssPercentile":0.01759,"ingestedAt":"2026-07-08T12:51:00.729Z","slug":"CVE-2026-46314","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ndrm/v3d: Reject empty multisync extension to prevent infinite loop\n\nv3d_get_extensions() walks a userspace-provided singly-linked list of\nioctl extensions without any bound on the chain length. A local user\ncan craft a self-referential extension (ext->next == &ext) with zero\nin_sync_count and out_sync_count, which bypasses the existing duplicate-\nextension guard:\n\n    if (se->in_sync_count || se->out_sync_count)\n            return -EINVAL;\n\nThe guard never fires because v3d_get_multisync_post_deps() returns\nimmediately when count is zero, leaving both fields at zero on every\niteration. The result is an infinite loop in kernel context, blocking\nthe calling thread and pegging a CPU core indefinitely.\n\nFix this by rejecting a multisync extension where both in_sync_count\nand out_sync_count are zero in v3d_get_multisync_submit_deps(). An\nempty multisync carries no synchronization information and serves no\nuseful purpose, so returning -EINVAL for such an extension is the\ncorrect defense against this attack vector.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}