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Fencer Vulns
high 8.1

CVE-2023-53186 json

skbuff: Fix a race between coalescing and releasing SKBs

published 2025-09-15 13 mo ago modified 2026-10-15 24 d ago also EUVD-2023-59790

cvss
8.1
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 18%
public exploits
0
none known

Summary

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

skbuff: Fix a race between coalescing and releasing SKBs

Commit 1effe8ca4e34 ("skbuff: fix coalescing for page_pool fragment recycling") allowed coalescing to proceed with non page pool page and page pool page when @from is cloned, i.e.

to->pp_recycle --> false from->pp_recycle --> true skb_cloned(from) --> true

However, it actually requires skb_cloned(@from) to hold true until coalescing finishes in this situation. If the other cloned SKB is released while the merging is in process, from_shinfo->nr_frags will be set to 0 toward the end of the function, causing the increment of frag page _refcount to be unexpectedly skipped resulting in inconsistent reference counts. Later when SKB(@to) is released, it frees the page directly even though the page pool page is still in use, leading to use-after-free or double-free errors. So it should be prohibited.

The double-free error message below prompted us to investigate: BUG: Bad page state in process swapper/1 pfn:0e0d1 page:00000000c6548b28 refcount:-1 mapcount:0 mapping:0000000000000000 index:0x2 pfn:0xe0d1 flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff) raw: 000fffffc0000000 0000000000000000 ffffffff00000101 0000000000000000 raw: 0000000000000002 0000000000000000 ffffffffffffffff 0000000000000000 page dumped because: nonzero _refcount

CPU: 1 PID: 0 Comm: swapper/1 Tainted: G E 6.2.0+ Call Trace: <IRQ> dump_stack_lvl+0x32/0x50 bad_page+0x69/0xf0 free_pcp_prepare+0x260/0x2f0 free_unref_page+0x20/0x1c0 skb_release_data+0x10b/0x1a0 napi_consume_skb+0x56/0x150 net_rx_action+0xf0/0x350 ? __napi_schedule+0x79/0x90 __do_softirq+0xc8/0x2b1 __irq_exit_rcu+0xb9/0xf0 common_interrupt+0x82/0xa0 </IRQ> <TASK> asm_common_interrupt+0x22/0x40 RIP: 0010:default_idle+0xb/0x20

Patch / fix

  • Linux Linux 5.15.108, 6.1.25, 6.2.12, 6.3
  • linux Debian 14, Debian 13, Debian 12 6.1.25-1

debian advisories DEBIAN-CVE-2023-53186

  • linux Ubuntu 22.04 LTS 5.15.0-79.86
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1042.47
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1039.47
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1039.44
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1035.38
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1039.44
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1045.52
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1025.30

ubuntu advisories UBUNTU-CVE-2023-53186

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

  • kpatch-patch-5_14_0-284_92_1 RHEL 9.2 E4S 1-13.el9_2
  • kpatch-patch-5_14_0-284_79_1 RHEL 9.2 E4S 1-15.el9_2
  • kpatch-patch-5_14_0-284_104_1 RHEL 9.2 E4S 1-11.el9_2
  • kpatch-patch-5_14_0-284_117_1 RHEL 9.2 E4S 1-8.el9_2
  • kpatch-patch-5_14_0-284_134_1 RHEL 9.2 E4S 1-2.el9_2
  • kernel RHEL 9.2 E4S 5.14.0-284.142.1.el9_2
  • perf RHEL 9.2 E4S 5.14.0-284.142.1.el9_2
  • rtla RHEL 9.2 E4S 5.14.0-284.142.1.el9_2

red hat advisories RHSA-2025:17896RHSA-2025:17734

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-2023-53186 updated cvss 7.0

kernel: skbuff: Fix a race between coalescing and releasing SKBs

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: workaround, no fix available
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) perf 5.14.0-284.142.1.el9_2, rtla 5.14.0-284.142.1.el9_2, kernel-devel-matched 5.14.0-284.142.1.el9_2, kernel-64k-devel-matched 5.14.0-284.142.1.el9_2, kernel-debug-devel-matched 5.14.0-284.142.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.142.1.el9_2, +5 more Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool 7.0.0-284.142.1.el9_2, kernel 5.14.0-284.142.1.el9_2, kernel-64k 5.14.0-284.142.1.el9_2, kernel-core 5.14.0-284.142.1.el9_2, kernel-tools 5.14.0-284.142.1.el9_2, python3-perf 5.14.0-284.142.1.el9_2, +33 more
    fixed: vendor fix RHSA-2025:17734
  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 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
total
Assessed
24 d ago

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization
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.