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CVE-2026-53256

Bluetooth: RFCOMM: hold listener socket in rfcomm_connect_ind() PUBLISHED

Description (CNA)

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: hold listener socket in rfcomm_connect_ind() rfcomm_get_sock_by_channel() scans rfcomm_sk_list under the list lock, but returns the selected listener after dropping that lock without taking a reference. rfcomm_connect_ind() then locks the listener, queues a child socket on it, and may notify it after unlocking it. The buggy scenario involves two paths, with each column showing the order within that path: rfcomm_connect_ind(): listener close: 1. Find parent in 1. close() enters rfcomm_get_sock_by_channel() rfcomm_sock_release(). 2. Drop rfcomm_sk_list.lock 2. rfcomm_sock_shutdown() without pinning parent. closes the listener. 3. Call lock_sock(parent) and 3. rfcomm_sock_kill() bt_accept_enqueue(parent, unlinks and puts parent. sk, true). 4. Read parent flags and may 4. parent can be freed. call sk_state_change(). If close wins the race, parent can be freed before rfcomm_connect_ind() reaches lock_sock(), bt_accept_enqueue(), or the deferred-setup callback. Take a reference on the listener before leaving rfcomm_sk_list.lock. After lock_sock() succeeds, recheck that it is still in BT_LISTEN before queueing a child, cache the deferred-setup bit while the parent is locked, and drop the reference after the last parent use. KASAN reported a slab-use-after-free in lock_sock_nested() from rfcomm_connect_ind(), with the freeing stack going through rfcomm_sock_kill() and rfcomm_sock_release().

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before f5ec76bdbeb80f75ad0be204371afffee0f8fac8; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before a07d741c077d4e34b16458241a94d29039386553; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 1f73f92f66251065a5f39b09a47cf05ea14d3107; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before de31973ef00e5aa55496f84cf6a44bb157a34e02; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before b0e33e409715c617e2a20f46f99aa5403a14dfda; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 8802413ce63175fb522a2bd609fb043a3550c720; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 6f4462d12133106460d7c046b95aad2491e3fddf; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 43c441edacf953b39517a44f5e5e10a93618b226
Linux / Linuxaffected 2.6.12; unaffected 0 before 2.6.12; unaffected 5.10.259 through 5.10.*; unaffected 5.15.210 through 5.15.*; unaffected 6.1.176 through 6.1.*; unaffected 6.6.143 through 6.6.*; unaffected 6.12.94 through 6.12.*; unaffected 6.18.36 through 6.18.*; unaffected 7.0.13 through 7.0.*; unaffected 7.1 through *

CWE

No CWE identifiers supplied.

References

ADP enrichment

siemens-SADP

No English description supplied.

CISA-ADP

No English description supplied.

No references supplied.