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Fencer Vulns
high 8.8

CVE-2022-49910 json

Bluetooth: L2CAP: Fix use-after-free caused by l2cap_reassemble_sdu

published 2025-05-01 18 mo ago modified 2026-08-05 3 mo ago also EUVD-2025-12858

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 19%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: L2CAP: Fix use-after-free caused by l2cap_reassemble_sdu

Fix the race condition between the following two flows that run in parallel:

1. l2cap_reassemble_sdu -> chan->ops->recv (l2cap_sock_recv_cb) -> __sock_queue_rcv_skb.

2. bt_sock_recvmsg -> skb_recv_datagram, skb_free_datagram.

An SKB can be queued by the first flow and immediately dequeued and freed by the second flow, therefore the callers of l2cap_reassemble_sdu can't use the SKB after that function returns. However, some places continue accessing struct l2cap_ctrl that resides in the SKB's CB for a short time after l2cap_reassemble_sdu returns, leading to a use-after-free condition (the stack trace is below, line numbers for kernel 5.19.8).

Fix it by keeping a local copy of struct l2cap_ctrl.

BUG: KASAN: use-after-free in l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth Read of size 1 at addr ffff88812025f2f0 by task kworker/u17:3/43169

Workqueue: hci0 hci_rx_work [bluetooth] Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:107 (discriminator 4)) print_report.cold (mm/kasan/report.c:314 mm/kasan/report.c:429) ? l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth kasan_report (mm/kasan/report.c:162 mm/kasan/report.c:493) ? l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth l2cap_rx (net/bluetooth/l2cap_core.c:7236 net/bluetooth/l2cap_core.c:7271) bluetooth ret_from_fork (arch/x86/entry/entry_64.S:306) </TASK>

Allocated by task 43169: kasan_save_stack (mm/kasan/common.c:39) __kasan_slab_alloc (mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469) kmem_cache_alloc_node (mm/slab.h:750 mm/slub.c:3243 mm/slub.c:3293) __alloc_skb (net/core/skbuff.c:414) l2cap_recv_frag (./include/net/bluetooth/bluetooth.h:425 net/bluetooth/l2cap_core.c:8329) bluetooth l2cap_recv_acldata (net/bluetooth/l2cap_core.c:8442) bluetooth hci_rx_work (net/bluetooth/hci_core.c:3642 net/bluetooth/hci_core.c:3832) bluetooth process_one_work (kernel/workqueue.c:2289) worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2437) kthread (kernel/kthread.c:376) ret_from_fork (arch/x86/entry/entry_64.S:306)

Freed by task 27920: kasan_save_stack (mm/kasan/common.c:39) kasan_set_track (mm/kasan/common.c:45) kasan_set_free_info (mm/kasan/generic.c:372) ____kasan_slab_free (mm/kasan/common.c:368 mm/kasan/common.c:328) slab_free_freelist_hook (mm/slub.c:1780) kmem_cache_free (mm/slub.c:3536 mm/slub.c:3553) skb_free_datagram (./include/net/sock.h:1578 ./include/net/sock.h:1639 net/core/datagram.c:323) bt_sock_recvmsg (net/bluetooth/af_bluetooth.c:295) bluetooth l2cap_sock_recvmsg (net/bluetooth/l2cap_sock.c:1212) bluetooth sock_read_iter (net/socket.c:1087) new_sync_read (./include/linux/fs.h:2052 fs/read_write.c:401) vfs_read (fs/read_write.c:482) ksys_read (fs/read_write.c:620) do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)

Patch / fix

  • Linux Linux 4.9.333, 4.14.299, 4.19.265, 5.4.224, 5.10.154, 5.15.78, 6.0.8, 6.1
  • linux Debian 14, Debian 13, Debian 12 6.0.8-1

debian advisories DEBIAN-CVE-2022-49910

  • kernel RHEL 9 5.14.0-162.18.1.el9_1
  • perf RHEL 9 5.14.0-162.18.1.el9_1
  • bpftool RHEL 9 5.14.0-162.18.1.el9_1
  • kernel-core RHEL 9 5.14.0-162.18.1.el9_1
  • kernel-tools RHEL 9 5.14.0-162.18.1.el9_1
  • python3-perf RHEL 9 5.14.0-162.18.1.el9_1
  • kernel-modules RHEL 9 5.14.0-162.18.1.el9_1
  • kernel-zfcpdump RHEL 9 5.14.0-162.18.1.el9_1

red hat advisories RHSA-2023:0951RHSA-2023:2951RHSA-2023:4151RHSA-2023:3388

  • kernel-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.167.1
  • kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.167.1
  • kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.167.1
  • kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +7 more 5.14.21-150400.24.167.1
  • kernel-zfcpdump SLES 15 SP4-LTSS, Manager Server 4.3 5.14.21-150400.24.167.1
  • kernel-obs-build SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.167.1
  • kernel-default-base SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +5 more 5.14.21-150400.24.167.1.150400.24.84.1
  • kernel-64kb SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS, SLE High Performance Computing 15 SP5-ESPOS 5.14.21-150500.55.110.1

suse advisories SUSE-SU-2025:02262-1SUSE-SU-2025:02173-1SUSE-SU-2025:01995-1SUSE-SU-2025:01983-1SUSE-SU-2025:01982-1SUSE-SU-2025:01966-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-49910 updated cvss 7.1

kernel: Bluetooth: L2CAP: Fix use-after-free caused by l2cap_reassemble_sdu

  • Red Hat Enterprise Linux 7 kernel-rt, kernel-rt-kvm, kernel-rt-trace, kernel-rt-debug-kvm, kernel-rt-trace-kvm Red Hat Enterprise Linux 8 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +6 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: workaround, no fix available “Fix deferred”
  • Red Hat CodeReady Linux Builder (v. 9) kernel-debuginfo-common-s390x 5.14.0-162.18.1.el9_1, kernel-debuginfo-common-x86_64 5.14.0-162.18.1.el9_1, kernel-debuginfo-common-aarch64 5.14.0-162.18.1.el9_1, kernel-debuginfo-common-ppc64le 5.14.0-162.18.1.el9_1
    fixed: vendor fix RHSA-2023:0951
  • Red Hat CodeReady Linux Builder EUS (v.8.6) kernel-debuginfo-common-x86_64 4.18.0-372.57.1.el8_6, kernel-debuginfo-common-aarch64 4.18.0-372.57.1.el8_6, kernel-debuginfo-common-ppc64le 4.18.0-372.57.1.el8_6
    fixed: vendor fix RHSA-2023:3388
  • Red Hat Enterprise Linux AppStream (v. 9) perf 5.14.0-162.18.1.el9_1, kernel-devel-matched 5.14.0-162.18.1.el9_1, kernel-debug-devel-matched 5.14.0-162.18.1.el9_1, kernel-debuginfo-common-s390x 5.14.0-162.18.1.el9_1, kernel-zfcpdump-devel-matched 5.14.0-162.18.1.el9_1, kernel-debuginfo-common-x86_64 5.14.0-162.18.1.el9_1, +2 more
    fixed: vendor fix RHSA-2023:0951
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-477.10.1.el8_8, kernel 4.18.0-477.10.1.el8_8, bpftool 4.18.0-477.10.1.el8_8, kernel-core 4.18.0-477.10.1.el8_8, kernel-tools 4.18.0-477.10.1.el8_8, python3-perf 4.18.0-477.10.1.el8_8, +15 more
    fixed: vendor fix RHSA-2023:2951
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-162.18.1.el9_1, bpftool 5.14.0-162.18.1.el9_1, kernel-core 5.14.0-162.18.1.el9_1, kernel-tools 5.14.0-162.18.1.el9_1, python3-perf 5.14.0-162.18.1.el9_1, kernel-modules 5.14.0-162.18.1.el9_1, +14 more
    fixed: vendor fix RHSA-2023:0951
  • Red Hat Enterprise Linux BaseOS EUS (v.8.6) perf 4.18.0-372.57.1.el8_6, kernel 4.18.0-372.57.1.el8_6, bpftool 4.18.0-372.57.1.el8_6, kernel-core 4.18.0-372.57.1.el8_6, kernel-tools 4.18.0-372.57.1.el8_6, python3-perf 4.18.0-372.57.1.el8_6, +15 more
    fixed: vendor fix RHSA-2023:3388
  • Red Hat Enterprise Linux Client (v. 7) perf 3.10.0-1160.95.1.el7, kernel 3.10.0-1160.95.1.el7, bpftool 3.10.0-1160.95.1.el7, python-perf 3.10.0-1160.95.1.el7, kernel-tools 3.10.0-1160.95.1.el7, kernel-tools-libs 3.10.0-1160.95.1.el7, +2 more Red Hat Enterprise Linux Client Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.95.1.el7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.95.1.el7
    fixed: vendor fix RHSA-2023:4151
show 4 more
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-477.10.1.el8_8, kernel-debuginfo-common-aarch64 4.18.0-477.10.1.el8_8, kernel-debuginfo-common-ppc64le 4.18.0-477.10.1.el8_8
    fixed: vendor fix RHSA-2023:2951
  • Red Hat Enterprise Linux Server (v. 7) perf 3.10.0-1160.95.1.el7, kernel 3.10.0-1160.95.1.el7, bpftool 3.10.0-1160.95.1.el7, python-perf 3.10.0-1160.95.1.el7, kernel-kdump 3.10.0-1160.95.1.el7, kernel-tools 3.10.0-1160.95.1.el7, +7 more Red Hat Enterprise Linux Server Optional (v. 7) kernel-debuginfo-common-ppc64 3.10.0-1160.95.1.el7, kernel-debuginfo-common-x86_64 3.10.0-1160.95.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-1160.95.1.el7 Red Hat Enterprise Linux Workstation (v. 7) perf 3.10.0-1160.95.1.el7, kernel 3.10.0-1160.95.1.el7, bpftool 3.10.0-1160.95.1.el7, python-perf 3.10.0-1160.95.1.el7, kernel-tools 3.10.0-1160.95.1.el7, kernel-tools-libs 3.10.0-1160.95.1.el7, +2 more Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.95.1.el7
    fixed: vendor fix RHSA-2023:4151
  • Red Hat Virtualization 4 Hypervisor for RHEL 8 perf 4.18.0-372.57.1.el8_6, kernel-debuginfo-common-x86_64 4.18.0-372.57.1.el8_6
    fixed: vendor fix RHSA-2023:3388
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.