{"id":"CVE-2024-40909","title":"bpf: Fix a potential use-after-free in bpf_link_free()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix a potential use-after-free in bpf_link_free()\n\nAfter commit 1a80dbcb2dba, bpf_link can be freed by\nlink->ops->dealloc_deferred, but the code still tests and us…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= ac48dc6ac9240f73bf08d29edf65c2deca93ee5d < e8ccda39b395169622855607085cdeef4d376e0f","Linux >= 876941f533e7b47fc69977fc4551c02f2d18af97 < 91cff53136daeff50816b0baeafd38a6976f6209","Linux >= 1a80dbcb2dbaf6e4c216e62e30fa7d3daa8001ce < fa97b8fed9896f1e89cb657513e483a152d4c382","Linux >= 1a80dbcb2dbaf6e4c216e62e30fa7d3daa8001ce < 2884dc7d08d98a89d8d65121524bb7533183a63a","Linux 5d8d447777564b35f67000e7838e7ccb64d525c8","Linux >= 6.6.26 < 6.6.35","Linux >= 6.8.5 < 6.9","Linux 6.9"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2024-09-10T17:06:09.099919Z"},"published":"2024-07-12","updated":"2026-10-30","sourceUpdated":"2026-10-30T12:18:36.759Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2024-40909","references":[{"url":"https://git.kernel.org/stable/c/e8ccda39b395169622855607085cdeef4d376e0f"},{"url":"https://git.kernel.org/stable/c/91cff53136daeff50816b0baeafd38a6976f6209"},{"url":"https://git.kernel.org/stable/c/fa97b8fed9896f1e89cb657513e483a152d4c382"},{"url":"https://git.kernel.org/stable/c/2884dc7d08d98a89d8d65121524bb7533183a63a"}],"tags":["cve.org"],"epss":0.00278,"epssPercentile":0.20328,"ingestedAt":"2026-11-03T12:44:28.823Z","slug":"CVE-2024-40909","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix a potential use-after-free in bpf_link_free()\n\nAfter commit 1a80dbcb2dba, bpf_link can be freed by\nlink->ops->dealloc_deferred, but the code still tests and uses\nlink->ops->dealloc afterward, which leads to a use-after-free as\nreported by syzbot. Actually, one of them should be sufficient, so\njust call one of them instead of both. Also add a WARN_ON() in case\nof any problematic implementation.\n\n## Affected\n\n- `Linux >= ac48dc6ac9240f73bf08d29edf65c2deca93ee5d < e8ccda39b395169622855607085cdeef4d376e0f`\n- `Linux >= 876941f533e7b47fc69977fc4551c02f2d18af97 < 91cff53136daeff50816b0baeafd38a6976f6209`\n- `Linux >= 1a80dbcb2dbaf6e4c216e62e30fa7d3daa8001ce < fa97b8fed9896f1e89cb657513e483a152d4c382`\n- `Linux >= 1a80dbcb2dbaf6e4c216e62e30fa7d3daa8001ce < 2884dc7d08d98a89d8d65121524bb7533183a63a`\n- `Linux 5d8d447777564b35f67000e7838e7ccb64d525c8`\n- `Linux >= 6.6.26 < 6.6.35`\n- `Linux >= 6.8.5 < 6.9`\n- `Linux 6.9`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}