{"id":"CVE-2026-98738","title":"Bluetooth: Serialize SMP remote OOB data access","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: Serialize SMP remote OOB data access\n\nbuild_pairing_cmd() looks up remote OOB data and copies its contents\nwithout holding hdev->lock, which serializes the l…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 02b05bd8b0a632e9a26795bced8f19ca6a5f7079 < 1e11412a1b9854a89d044576d616675b16141d87","Linux >= 02b05bd8b0a632e9a26795bced8f19ca6a5f7079 < 889c61e3d0f1091a958e4b2a24b20bab23d915c4","Linux >= 02b05bd8b0a632e9a26795bced8f19ca6a5f7079 < df5162eeb10e69fe0c2349503882c4a09077f001","Linux >= 02b05bd8b0a632e9a26795bced8f19ca6a5f7079 < 81a2345f1984f0b36d3226571bc196316a01b648","Linux 3.19"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:47:21.503Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98738","references":[{"url":"https://git.kernel.org/stable/c/1e11412a1b9854a89d044576d616675b16141d87"},{"url":"https://git.kernel.org/stable/c/889c61e3d0f1091a958e4b2a24b20bab23d915c4"},{"url":"https://git.kernel.org/stable/c/df5162eeb10e69fe0c2349503882c4a09077f001"},{"url":"https://git.kernel.org/stable/c/81a2345f1984f0b36d3226571bc196316a01b648"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T16:47:32.503Z","slug":"CVE-2026-98738","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: Serialize SMP remote OOB data access\n\nbuild_pairing_cmd() looks up remote OOB data and copies its contents\nwithout holding hdev->lock, which serializes the list's writers. After\nSMP finds an entry, a concurrent management Remove Remote OOB Data\ncommand can unlink and free it before SMP reads its present flag or\ncopies its random and confirmation values. Removal can also invalidate\nan entry while the lookup is still traversing the list.\n\nKASAN reported:\n\n  BUG: KASAN: slab-use-after-free in build_pairing_cmd+0x948/0x9b0\n  Call Trace:\n   build_pairing_cmd+0x948/0x9b0\n   smp_recv_cb+0x459f/0x8110\n   l2cap_recv_frame+0xf14/0x9190\n   l2cap_recv_acldata+0xa64/0xd40\n   hci_rx_work+0x4ca/0x730\n\n  Allocated by task 87:\n   hci_add_remote_oob_data+0x11d/0x530\n   add_remote_oob_data+0x282/0x400\n   hci_sock_sendmsg+0x1033/0x1ea0\n\n  Freed by task 93:\n   hci_remote_oob_data_clear+0x108/0x1c0\n   remove_remote_oob_data+0x198/0x220\n   hci_sock_sendmsg+0x1033/0x1ea0\n\nTaking hdev->lock in build_pairing_cmd() would recurse for callers that\nalready hold it and invert the device-to-L2CAP lock order on the receive\npath. Add a per-device remote_oob_lock instead, held across the SMP\nlookup and copies and by the add, remove and clear helpers. Cover\ninitialization and in-place updates as well, so SMP cannot read partially\ninitialized or updated OOB values. Release the mutex on allocation\nfailure, preserving the existing error return.\n\nThe new critical sections acquire no device, connection or channel locks.\nWriters retain their existing hdev->lock protection, which continues to\nserialize the other readers without changing their locking or behavior.\n\n## Affected\n\n- `Linux >= 02b05bd8b0a632e9a26795bced8f19ca6a5f7079 < 1e11412a1b9854a89d044576d616675b16141d87`\n- `Linux >= 02b05bd8b0a632e9a26795bced8f19ca6a5f7079 < 889c61e3d0f1091a958e4b2a24b20bab23d915c4`\n- `Linux >= 02b05bd8b0a632e9a26795bced8f19ca6a5f7079 < df5162eeb10e69fe0c2349503882c4a09077f001`\n- `Linux >= 02b05bd8b0a632e9a26795bced8f19ca6a5f7079 < 81a2345f1984f0b36d3226571bc196316a01b648`\n- `Linux 3.19`\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":[]}