Skip to content
Fencer Vulns
medium 5.5

CVE-2022-49908 json

Bluetooth: L2CAP: Fix memory leak in vhci_write

published 2025-05-01 18 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-12865

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

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

Bluetooth: L2CAP: Fix memory leak in vhci_write

Syzkaller reports a memory leak as follows: ==================================== BUG: memory leak unreferenced object 0xffff88810d81ac00 (size 240): [...] hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff838733d9>] __alloc_skb+0x1f9/0x270 net/core/skbuff.c:418 [<ffffffff833f742f>] alloc_skb include/linux/skbuff.h:1257 [inline] [<ffffffff833f742f>] bt_skb_alloc include/net/bluetooth/bluetooth.h:469 [inline] [<ffffffff833f742f>] vhci_get_user drivers/bluetooth/hci_vhci.c:391 [inline] [<ffffffff833f742f>] vhci_write+0x5f/0x230 drivers/bluetooth/hci_vhci.c:511 [<ffffffff815e398d>] call_write_iter include/linux/fs.h:2192 [inline] [<ffffffff815e398d>] new_sync_write fs/read_write.c:491 [inline] [<ffffffff815e398d>] vfs_write+0x42d/0x540 fs/read_write.c:578 [<ffffffff815e3cdd>] ksys_write+0x9d/0x160 fs/read_write.c:631 [<ffffffff845e0645>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff845e0645>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff84600087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd ====================================

HCI core will uses hci_rx_work() to process frame, which is queued to the hdev->rx_q tail in hci_recv_frame() by HCI driver.

Yet the problem is that, HCI core may not free the skb after handling ACL data packets. To be more specific, when start fragment does not contain the L2CAP length, HCI core just copies skb into conn->rx_skb and finishes frame process in l2cap_recv_acldata(), without freeing the skb, which triggers the above memory leak.

This patch solves it by releasing the relative skb, after processing the above case in l2cap_recv_acldata().

Patch / fix

  • Linux Linux 5.15.78, 6.0.8, 6.1
  • linux Debian 14, Debian 13, Debian 12 6.0.8-1

debian advisories DEBIAN-CVE-2022-49908

  • linux Ubuntu 22.04 LTS 5.15.0-60.66
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1030.34
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1029.36
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1027.32
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1025.28
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1028.33
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1033.40
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1015.19

ubuntu advisories UBUNTU-CVE-2022-49908

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • perf rhev hypervisor 4.4, RHEL 8.6 EUS 4.18.0-372.91.1.el8_6
  • kernel RHEL 9 5.14.0-284.11.1.el9_2
  • perf RHEL 9 5.14.0-284.11.1.el9_2
  • rtla RHEL 9 5.14.0-284.11.1.el9_2
  • bpftool RHEL 9 7.0.0-284.11.1.el9_2
  • kernel-64k RHEL 9 5.14.0-284.11.1.el9_2
  • kernel-core RHEL 9 5.14.0-284.11.1.el9_2
  • kernel-tools RHEL 9 5.14.0-284.11.1.el9_2

red hat advisories RHSA-2024:0724RHSA-2023:2458RHSA-2023:2951

  • 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-2025:01966-1SUSE-SU-2025:01918-1

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-2022-49908 updated cvss 5.5

kernel: Bluetooth: L2CAP: Fix memory leak in vhci_write

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more 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
    affected: no fix planned “Out of support scope”
  • 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: no fix available “Fix deferred”
  • Red Hat CodeReady Linux Builder EUS (v.8.6) kernel-debuginfo-common-x86_64 4.18.0-372.91.1.el8_6, kernel-debuginfo-common-aarch64 4.18.0-372.91.1.el8_6, kernel-debuginfo-common-ppc64le 4.18.0-372.91.1.el8_6
    fixed: vendor fix RHSA-2024:0724
  • Red Hat Enterprise Linux AppStream (v. 9) perf 5.14.0-284.11.1.el9_2, rtla 5.14.0-284.11.1.el9_2, kernel-devel-matched 5.14.0-284.11.1.el9_2, kernel-64k-devel-matched 5.14.0-284.11.1.el9_2, kernel-debug-devel-matched 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.11.1.el9_2, +5 more
    fixed: vendor fix RHSA-2023:2458
  • 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) bpftool 7.0.0-284.11.1.el9_2, kernel 5.14.0-284.11.1.el9_2, kernel-64k 5.14.0-284.11.1.el9_2, kernel-core 5.14.0-284.11.1.el9_2, kernel-tools 5.14.0-284.11.1.el9_2, python3-perf 5.14.0-284.11.1.el9_2, +28 more
    fixed: vendor fix RHSA-2023:2458
  • Red Hat Enterprise Linux BaseOS EUS (v.8.6) perf 4.18.0-372.91.1.el8_6, kernel 4.18.0-372.91.1.el8_6, bpftool 4.18.0-372.91.1.el8_6, kernel-core 4.18.0-372.91.1.el8_6, kernel-tools 4.18.0-372.91.1.el8_6, python3-perf 4.18.0-372.91.1.el8_6, +15 more
    fixed: vendor fix RHSA-2024:0724
  • 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
show 3 more
  • Red Hat Enterprise Linux CRB (v. 9) kernel-debuginfo-common-s390x 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-x86_64 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-aarch64 5.14.0-284.11.1.el9_2, kernel-debuginfo-common-ppc64le 5.14.0-284.11.1.el9_2
    fixed: vendor fix RHSA-2023:2458
  • Red Hat Virtualization 4 Hypervisor for RHEL 8 perf 4.18.0-372.91.1.el8_6, kernel-debuginfo-common-x86_64 4.18.0-372.91.1.el8_6
    fixed: vendor fix RHSA-2024:0724
  • 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

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
13 mo ago

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-401 Missing Release of Memory after Effective Lifetime
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.