{"id":"CVE-2026-98107","summary":"Bluetooth: L2CAP: fix out-of-bounds write in l2cap_ecred_connect","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: fix out-of-bounds write in l2cap_ecred_connect\n\nl2cap_chan_connect() tries to ensure there are no more than\nL2CAP_ECRED_CONN_SCID_MAX pending ECRED channels, so they fit in the\nsame L2CAP_ECRED_CONN_REQ that l2cap_ecred_connect() constructs.\n\nHowever, the check only counts deferred channels.  If 6 L2CAP sockets\nare connected at the same time in order DDDDND (D=deferred,\nN=non-deferred), the last can bump the total to max+1.  It results to\none __le16 written out of bounds of the scid array, and an invalid\nECRED_CONN_REQ being sent.\n\nFix by leaving room for the non-deferred pending ECRED channels in the\ncounting in l2cap_chan_connect(), so the limit can't be exceeded.\n\nMove counting under same critical section where the channel is added.\nAlthough race conditions involving this appear unreachable, it's easier\nto see.\n\nAlso add WARN_ON_ONCE check in l2cap_ecred_defer_connect() to make this\nless brittle.","modified":"2026-09-26T03:48:37.240100177Z","published":"2026-09-25T10:35:56.340Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98107.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/56c2b5831d39dc84aad2573dc3e197af1a872a05"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6da5c0331fc3ef0c7b8df8269523fc3b2cce1e65"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ce0927eb3ee2939fab5ce3f9334bfd2fafb38481"},{"type":"WEB","url":"https://git.kernel.org/stable/c/df8c3af6132640da4788e96a02d653e642059803"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98107.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98107"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"da49b602f7f75ccc91386e1274b3ef71676cd092"},{"fixed":"ce0927eb3ee2939fab5ce3f9334bfd2fafb38481"},{"fixed":"6da5c0331fc3ef0c7b8df8269523fc3b2cce1e65"},{"fixed":"df8c3af6132640da4788e96a02d653e642059803"},{"fixed":"56c2b5831d39dc84aad2573dc3e197af1a872a05"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98107.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.7.0"},{"fixed":"6.12.111"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.53"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98107.json"}}],"schema_version":"1.9.0"}