{"id":"CVE-2026-46314","summary":"drm/v3d: Reject empty multisync extension to prevent infinite loop","details":"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 bound on the chain length. A local user\ncan craft a self-referential extension (ext-\u003enext == &ext) with zero\nin_sync_count and out_sync_count, which bypasses the existing duplicate-\nextension guard:\n\n    if (se-\u003ein_sync_count || se-\u003eout_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.","modified":"2026-07-10T03:54:24.657189411Z","published":"2026-06-08T15:50:45.305Z","related":["openSUSE-SU-2026:11014-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46314.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/309abbddeca0c12714721928a819ef45e5710998"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4fa42a249e8cd6ed17aea04e5695b6e9001f2433"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9c5164781cb388d219d8f49fa0f0b04cf86ad544"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fb44d589bf3148e13452185a6e772a7efbf2d684"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46314.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46314"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"e4165ae8304e5ea822fbe5909dd3be5445c058b7"},{"fixed":"309abbddeca0c12714721928a819ef45e5710998"},{"fixed":"4fa42a249e8cd6ed17aea04e5695b6e9001f2433"},{"fixed":"9c5164781cb388d219d8f49fa0f0b04cf86ad544"},{"fixed":"fb44d589bf3148e13452185a6e772a7efbf2d684"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46314.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.176"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.18.33"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46314.json"}}],"schema_version":"1.7.5"}