CVE-2026-98735
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: Serialize ACL scheduling with channel deletion hci_chan_sent() selects a channel under RCU but drops the read lock before accessing chan->conn and returning the channel. The ACL and LE schedulers then use its packet queue and update its transmit counters without any protection against channel deletion. After TX selects a channel and releases RCU, a disconnect command timeout on the separate request workqueue can run hci_conn_failed() and l2cap_conn_del(). hci_chan_del() can then unlink the channel, complete synchronize_rcu(), purge its queue and free it before TX resumes. This causes use-after-free both in hci_chan_sent() and in its callers. KASAN reported: BUG: KASAN: slab-use-after-free in hci_chan_sent+0x892/0x9b0 Workqueue: hci0 hci_tx_work Call Trace: hci_chan_sent+0x892/0x9b0 hci_tx_work+0x5e6/0xb70 Allocated by task 91: hci_chan_create+0xe3/0x350 l2cap_conn_add.part.0+0x12/0xa30 l2cap_chan_connect+0x110d/0x1b60 l2cap_sock_connect+0x310/0x530 Freed by task 99: hci_chan_del+0x11f/0x170 l2cap_conn_del+0x4f1/0x800 l2cap_connect_cfm+0x88c/0xd30 hci_conn_failed+0x150/0x250 hci_abort_conn_sync+0x3e3/0x800 hci_cmd_sync_run+0x7e/0xc0 hci_abort_conn+0x105/0x1f0 disconnect_sync+0x157/0x290 hci_cmd_sync_work+0x13c/0x290 Hold the existing device mutex across channel selection and transmission in both schedulers to serialize them with channel teardown. Keep timeout handling outside the critical sections because hci_link_tx_to() acquires the same mutex. This also permits the transmit path to sleep, unlike extending the RCU read-side critical section across packet submission.
View original CVE JSON
{
"id": "CVE-2026-98735",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-18T16:17:27.127",
"lastModified": "2026-10-30T13:21:22.250",
"vulnStatus": "Received",
"cveTags": [],
"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": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/bluetooth/hci_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "3eff45eaf81780dad25c167bbaafa7d25ae407da",
"lessThan": "126714c495bf31a5e71411b8e0b65a685bb5e58d",
"versionType": "git",
"status": "affected"
},
{
"version": "3eff45eaf81780dad25c167bbaafa7d25ae407da",
"lessThan": "7fbeda3dcd5f54e7429f4b5e2cfa7344b7e9b1c9",
"versionType": "git",
"status": "affected"
},
{
"version": "3eff45eaf81780dad25c167bbaafa7d25ae407da",
"lessThan": "74667f6eb7c12b65c56e02e0f527e4099db4ebfd",
"versionType": "git",
"status": "affected"
},
{
"version": "3eff45eaf81780dad25c167bbaafa7d25ae407da",
"lessThan": "780affacd92977fd9b819bdc4f26a6832cb27fda",
"versionType": "git",
"status": "affected"
},
{
"version": "3eff45eaf81780dad25c167bbaafa7d25ae407da",
"lessThan": "51f95ea451f25d7e3f048c0f438f04fa74688aae",
"versionType": "git",
"status": "affected"
},
{
"version": "3eff45eaf81780dad25c167bbaafa7d25ae407da",
"lessThan": "86e9708f9d19a7f1bd5dc9c1652d07707f79f5bd",
"versionType": "git",
"status": "affected"
},
{
"version": "3eff45eaf81780dad25c167bbaafa7d25ae407da",
"lessThan": "4fda8f0abeea9929036446d89a476fb8298abcb0",
"versionType": "git",
"status": "affected"
},
{
"version": "3eff45eaf81780dad25c167bbaafa7d25ae407da",
"lessThan": "f4845ab191a4f686a5da481fbba90ed73bb693b0",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/bluetooth/hci_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "3.3",
"status": "affected"
},
{
"version": "0",
"lessThan": "3.3",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.273",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.224",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.191",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.160",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.113",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.56",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.10",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/126714c495bf31a5e71411b8e0b65a685bb5e58d",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/4fda8f0abeea9929036446d89a476fb8298abcb0",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/51f95ea451f25d7e3f048c0f438f04fa74688aae",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/74667f6eb7c12b65c56e02e0f527e4099db4ebfd",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/780affacd92977fd9b819bdc4f26a6832cb27fda",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/7fbeda3dcd5f54e7429f4b5e2cfa7344b7e9b1c9",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/86e9708f9d19a7f1bd5dc9c1652d07707f79f5bd",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f4845ab191a4f686a5da481fbba90ed73bb693b0",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}