{"id":"CVE-2026-98600","summary":"Bluetooth: RFCOMM: Reject short EA=0 frames in rfcomm_recv_frame()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: Reject short EA=0 frames in rfcomm_recv_frame()\n\nWhile rfcomm_recv_frame() verifies that skb-\u003elen is at least\nsizeof(*hdr) + 1 (4 bytes: 3-byte header + 1-byte FCS), an RFCOMM frame\nwith an extended 2-byte length field (!__test_ea(hdr-\u003elen)) has a 4-byte\nheader plus a 1-byte FCS (5 bytes minimum, sizeof(*hdr) + 2).\n\nWhen a 4-byte RFCOMM frame with EA == 0 arrives:\n1. The initial skb-\u003elen \u003c sizeof(*hdr) + 1 check passes (4 \u003c 4 is false).\n2. Trimming the FCS byte decrements skb-\u003elen to 3.\n3. If __check_fcs() succeeds, skb_pull(skb, 4) fails (4 \u003e 3) and returns\n   NULL without advancing skb-\u003edata.\n4. Because the return value of skb_pull() is ignored, the un-pulled\n   3-byte struct rfcomm_hdr remains at skb-\u003edata and is either queued as\n   application payload via rfcomm_recv_data() or parsed as a multiplexer\n   control command via rfcomm_recv_mcc() on DLCI 0.\n\nFix this by extending the length check in rfcomm_recv_frame() to also\nrequire skb-\u003elen \u003e= sizeof(*hdr) + 2 when !__test_ea(hdr-\u003elen).","modified":"2026-10-20T02:30:45.461480885Z","published":"2026-10-18T15:19:12.864Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98600.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6d91041bb38b97e2feb625123cc0529d7b83a0e1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/71ccacde407b7d8f0ef48974a0d2524602fd5c44"},{"type":"WEB","url":"https://git.kernel.org/stable/c/76876fd26569302d26d91cbe8b75fa8e66cf8969"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7a1781a2f3a9667b3065d402d1f11986a2363e08"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9240fc1f2cde5331c61608da21b00394602ca762"},{"type":"WEB","url":"https://git.kernel.org/stable/c/97711b964877242933484989224a3c4c5d88a5ee"},{"type":"WEB","url":"https://git.kernel.org/stable/c/be00deee60044ffa820f9436415caeb665b2cda0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c25587fa26761e623198b4f47151fe79d09ccde6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98600.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98600"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"fb40eda15122f6b780228639c1ead6820340ff54"},{"fixed":"76876fd26569302d26d91cbe8b75fa8e66cf8969"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"3829af5fab5a22405bf1e7d69068c2ec0fce46ca"},{"fixed":"97711b964877242933484989224a3c4c5d88a5ee"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b161eacd7fa4a2d765724b5504ac6cc388e48f80"},{"fixed":"7a1781a2f3a9667b3065d402d1f11986a2363e08"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"30d1d9f3495463f7c026e4c553127f79b486fcd6"},{"fixed":"c25587fa26761e623198b4f47151fe79d09ccde6"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"67dc3b40fae71b6b11c71e7ff69bac0758818c05"},{"fixed":"71ccacde407b7d8f0ef48974a0d2524602fd5c44"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"bbc310caa2b6bf5fe42896ba27da0fbc12e4ac51"},{"fixed":"be00deee60044ffa820f9436415caeb665b2cda0"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b230e5bf501c5edaf2eb0991cb862ac142031d4b"},{"fixed":"9240fc1f2cde5331c61608da21b00394602ca762"},{"fixed":"6d91041bb38b97e2feb625123cc0529d7b83a0e1"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.12.111"},{"fixed":"6.12.112"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.18.53"},{"fixed":"6.18.55"}]}],"versions":["v6.12.111","v6.18.54","v6.18.53"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98600.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.112"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.55"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98600.json"}}],"schema_version":"1.9.0"}