{"id":"CVE-2026-90393","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix potential UAF in bpf_netns_link_update_prog\n\nIn bpf_netns_link_update_prog, the checks for old_prog and prog type\nare currently performed locklessly before acq…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix potential UAF in bpf_netns_link_update_prog\n\nIn bpf_netns_link_update_prog, the checks for old_prog and prog type\nare currently performed locklessly before acq…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < d462b5481d77ce7df8a5ff89a699386f00c9214d","Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < bdddf3e1493ee973619c154a57071ce67f78598b","Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < 79a66fd997d4eecf17302d613194879eb32e0986","Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < f4ce6803df4095777191d800bebc50219b615ca0","Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < 277168cb9d153ce8e9c3f9275670e32ae61b41d6","Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < bda86e9f31b9a296b6e64a51c91dc776fc9f613e","Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < 923f559e95b89b33c7e1793b3d8f7f4ec9b2e4b7","Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < 5c5997836381010fc5907b36bc17d3b19407e933","Linux 5.8"],"published":"2026-09-17","updated":"2026-09-17","sourceUpdated":"2026-09-17T17:17:38.903","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90393","references":[{"url":"https://git.kernel.org/stable/c/277168cb9d153ce8e9c3f9275670e32ae61b41d6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5c5997836381010fc5907b36bc17d3b19407e933","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/79a66fd997d4eecf17302d613194879eb32e0986","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/923f559e95b89b33c7e1793b3d8f7f4ec9b2e4b7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bda86e9f31b9a296b6e64a51c91dc776fc9f613e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bdddf3e1493ee973619c154a57071ce67f78598b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d462b5481d77ce7df8a5ff89a699386f00c9214d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f4ce6803df4095777191d800bebc50219b615ca0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-17T16:21:47.803Z","epss":0.00227,"epssPercentile":0.13634,"slug":"CVE-2026-90393","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix potential UAF in bpf_netns_link_update_prog\n\nIn bpf_netns_link_update_prog, the checks for old_prog and prog type\nare currently performed locklessly before acquiring netns_bpf_mutex.\nThis creates a race condition that can lead to a UAF issue.\n\nIf two threads concurrently execute BPF_LINK_UPDATE on the same netns\nlink, the following execution path can trigger a UAF:\n\nCPU0                                          CPU1\nbpf_netns_link_update_prog\n  if (old_prog && old_prog != link->prog)\n    return -EPERM;\n                                              bpf_netns_link_update_prog\n                                                if (old_prog && old_prog != link->prog)\n                                                ...\n                                                old_prog = xchg(&link->prog, new_prog);\n                                                bpf_prog_put(old_prog);\n  if (new_prog->type != link->prog->type) <-- trigger UAF\n\nFix this by moving the old_prog and prog->type checks inside the\nnetns_bpf_mutex critical section. Meanwhile, use guard() to simplify\nlock management and avoid all the goto jumping.\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":[]}