{"id":"CVE-2026-98735","state":"PUBLISHED","title":"Bluetooth: hci_core: Serialize ACL scheduling with channel deletion","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_core: Serialize ACL scheduling with channel deletion\n\nhci_chan_sent() selects a channel under RCU but drops the read lock before\naccessing chan->conn and returning the channel. The ACL and LE schedulers\nthen use its packet queue and update its transmit counters without any\nprotection against channel deletion.\n\nAfter TX selects a channel and releases RCU, a disconnect command timeout\non the separate request workqueue can run hci_conn_failed() and\nl2cap_conn_del(). hci_chan_del() can then unlink the channel, complete\nsynchronize_rcu(), purge its queue and free it before TX resumes. This\ncauses use-after-free both in hci_chan_sent() and in its callers.\n\nKASAN reported:\n\n  BUG: KASAN: slab-use-after-free in hci_chan_sent+0x892/0x9b0\n  Workqueue: hci0 hci_tx_work\n  Call Trace:\n   hci_chan_sent+0x892/0x9b0\n   hci_tx_work+0x5e6/0xb70\n  Allocated by task 91:\n   hci_chan_create+0xe3/0x350\n   l2cap_conn_add.part.0+0x12/0xa30\n   l2cap_chan_connect+0x110d/0x1b60\n   l2cap_sock_connect+0x310/0x530\n  Freed by task 99:\n   hci_chan_del+0x11f/0x170\n   l2cap_conn_del+0x4f1/0x800\n   l2cap_connect_cfm+0x88c/0xd30\n   hci_conn_failed+0x150/0x250\n   hci_abort_conn_sync+0x3e3/0x800\n   hci_cmd_sync_run+0x7e/0xc0\n   hci_abort_conn+0x105/0x1f0\n   disconnect_sync+0x157/0x290\n   hci_cmd_sync_work+0x13c/0x290\n\nHold the existing device mutex across channel selection and transmission\nin both schedulers to serialize them with channel teardown. Keep timeout\nhandling outside the critical sections because hci_link_tx_to() acquires\nthe same mutex. This also permits the transmit path to sleep, unlike\nextending the RCU read-side critical section across packet submission.","publishedAt":"2026-10-18T15:47:13.062Z","updatedAt":"2026-10-30T12:39:11.976Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"126714c495bf31a5e71411b8e0b65a685bb5e58d","versionType":"git"},{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"7fbeda3dcd5f54e7429f4b5e2cfa7344b7e9b1c9","versionType":"git"},{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"74667f6eb7c12b65c56e02e0f527e4099db4ebfd","versionType":"git"},{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"780affacd92977fd9b819bdc4f26a6832cb27fda","versionType":"git"},{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"51f95ea451f25d7e3f048c0f438f04fa74688aae","versionType":"git"},{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"86e9708f9d19a7f1bd5dc9c1652d07707f79f5bd","versionType":"git"},{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"4fda8f0abeea9929036446d89a476fb8298abcb0","versionType":"git"},{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"f4845ab191a4f686a5da481fbba90ed73bb693b0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.3","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_core.c"]}],"references":["https://git.kernel.org/stable/c/126714c495bf31a5e71411b8e0b65a685bb5e58d","https://git.kernel.org/stable/c/7fbeda3dcd5f54e7429f4b5e2cfa7344b7e9b1c9","https://git.kernel.org/stable/c/74667f6eb7c12b65c56e02e0f527e4099db4ebfd","https://git.kernel.org/stable/c/780affacd92977fd9b819bdc4f26a6832cb27fda","https://git.kernel.org/stable/c/51f95ea451f25d7e3f048c0f438f04fa74688aae","https://git.kernel.org/stable/c/86e9708f9d19a7f1bd5dc9c1652d07707f79f5bd","https://git.kernel.org/stable/c/4fda8f0abeea9929036446d89a476fb8298abcb0","https://git.kernel.org/stable/c/f4845ab191a4f686a5da481fbba90ed73bb693b0"],"weaknesses":[],"ingestedAt":"2026-10-30T12:58:04.520Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98735.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98735","state":"PUBLISHED","datePublished":"2026-10-18T15:47:13.062Z","dateUpdated":"2026-10-30T12:39:11.976Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.367Z"},"containers":{"cna":{"title":"Bluetooth: hci_core: Serialize ACL scheduling with channel deletion","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_core: Serialize ACL scheduling with channel deletion\n\nhci_chan_sent() selects a channel under RCU but drops the read lock before\naccessing chan->conn and returning the channel. The ACL and LE schedulers\nthen use its packet queue and update its transmit counters without any\nprotection against channel deletion.\n\nAfter TX selects a channel and releases RCU, a disconnect command timeout\non the separate request workqueue can run hci_conn_failed() and\nl2cap_conn_del(). hci_chan_del() can then unlink the channel, complete\nsynchronize_rcu(), purge its queue and free it before TX resumes. This\ncauses use-after-free both in hci_chan_sent() and in its callers.\n\nKASAN reported:\n\n  BUG: KASAN: slab-use-after-free in hci_chan_sent+0x892/0x9b0\n  Workqueue: hci0 hci_tx_work\n  Call Trace:\n   hci_chan_sent+0x892/0x9b0\n   hci_tx_work+0x5e6/0xb70\n  Allocated by task 91:\n   hci_chan_create+0xe3/0x350\n   l2cap_conn_add.part.0+0x12/0xa30\n   l2cap_chan_connect+0x110d/0x1b60\n   l2cap_sock_connect+0x310/0x530\n  Freed by task 99:\n   hci_chan_del+0x11f/0x170\n   l2cap_conn_del+0x4f1/0x800\n   l2cap_connect_cfm+0x88c/0xd30\n   hci_conn_failed+0x150/0x250\n   hci_abort_conn_sync+0x3e3/0x800\n   hci_cmd_sync_run+0x7e/0xc0\n   hci_abort_conn+0x105/0x1f0\n   disconnect_sync+0x157/0x290\n   hci_cmd_sync_work+0x13c/0x290\n\nHold the existing device mutex across channel selection and transmission\nin both schedulers to serialize them with channel teardown. Keep timeout\nhandling outside the critical sections because hci_link_tx_to() acquires\nthe same mutex. This also permits the transmit path to sleep, unlike\nextending the RCU read-side critical section across packet submission."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"126714c495bf31a5e71411b8e0b65a685bb5e58d","versionType":"git"},{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"7fbeda3dcd5f54e7429f4b5e2cfa7344b7e9b1c9","versionType":"git"},{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"74667f6eb7c12b65c56e02e0f527e4099db4ebfd","versionType":"git"},{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"780affacd92977fd9b819bdc4f26a6832cb27fda","versionType":"git"},{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"51f95ea451f25d7e3f048c0f438f04fa74688aae","versionType":"git"},{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"86e9708f9d19a7f1bd5dc9c1652d07707f79f5bd","versionType":"git"},{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"4fda8f0abeea9929036446d89a476fb8298abcb0","versionType":"git"},{"version":"3eff45eaf81780dad25c167bbaafa7d25ae407da","status":"affected","lessThan":"f4845ab191a4f686a5da481fbba90ed73bb693b0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.3","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_core.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/126714c495bf31a5e71411b8e0b65a685bb5e58d"},{"url":"https://git.kernel.org/stable/c/7fbeda3dcd5f54e7429f4b5e2cfa7344b7e9b1c9"},{"url":"https://git.kernel.org/stable/c/74667f6eb7c12b65c56e02e0f527e4099db4ebfd"},{"url":"https://git.kernel.org/stable/c/780affacd92977fd9b819bdc4f26a6832cb27fda"},{"url":"https://git.kernel.org/stable/c/51f95ea451f25d7e3f048c0f438f04fa74688aae"},{"url":"https://git.kernel.org/stable/c/86e9708f9d19a7f1bd5dc9c1652d07707f79f5bd"},{"url":"https://git.kernel.org/stable/c/4fda8f0abeea9929036446d89a476fb8298abcb0"},{"url":"https://git.kernel.org/stable/c/f4845ab191a4f686a5da481fbba90ed73bb693b0"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:39:11.976Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"6.12.113"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"6.18.56"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"7.2.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}