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Fencer Vulns
critical 9.8

CVE-2025-37750 in the critical feed json

smb: client: fix UAF in decryption with multichannel

published 2025-05-01 18 mo ago modified 2026-10-30 10 d ago also EUVD-2025-13072

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits
0
none known

Summary

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

smb: client: fix UAF in decryption with multichannel

After commit f7025d861694 ("smb: client: allocate crypto only for primary server") and commit b0abcd65ec54 ("smb: client: fix UAF in async decryption"), the channels started reusing AEAD TFM from primary channel to perform synchronous decryption, but that can't done as there could be multiple cifsd threads (one per channel) simultaneously accessing it to perform decryption.

This fixes the following KASAN splat when running fstest generic/249 with 'vers=3.1.1,multichannel,max_channels=4,seal' against Windows Server 2022:

BUG: KASAN: slab-use-after-free in gf128mul_4k_lle+0xba/0x110 Read of size 8 at addr ffff8881046c18a0 by task cifsd/986 CPU: 3 UID: 0 PID: 986 Comm: cifsd Not tainted 6.15.0-rc1 #1 PREEMPT(voluntary) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-3.fc41 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x5d/0x80 print_report+0x156/0x528 ? gf128mul_4k_lle+0xba/0x110 ? __virt_addr_valid+0x145/0x300 ? __phys_addr+0x46/0x90 ? gf128mul_4k_lle+0xba/0x110 kasan_report+0xdf/0x1a0 ? gf128mul_4k_lle+0xba/0x110 gf128mul_4k_lle+0xba/0x110 ghash_update+0x189/0x210 shash_ahash_update+0x295/0x370 ? __pfx_shash_ahash_update+0x10/0x10 ? __pfx_shash_ahash_update+0x10/0x10 ? __pfx_extract_iter_to_sg+0x10/0x10 ? ___kmalloc_large_node+0x10e/0x180 ? __asan_memset+0x23/0x50 crypto_ahash_update+0x3c/0xc0 gcm_hash_assoc_remain_continue+0x93/0xc0 crypt_message+0xe09/0xec0 [cifs] ? __pfx_crypt_message+0x10/0x10 [cifs] ? _raw_spin_unlock+0x23/0x40 ? __pfx_cifs_readv_from_socket+0x10/0x10 [cifs] decrypt_raw_data+0x229/0x380 [cifs] ? __pfx_decrypt_raw_data+0x10/0x10 [cifs] ? __pfx_cifs_read_iter_from_socket+0x10/0x10 [cifs] smb3_receive_transform+0x837/0xc80 [cifs] ? __pfx_smb3_receive_transform+0x10/0x10 [cifs] ? __pfx___might_resched+0x10/0x10 ? __pfx_smb3_is_transform_hdr+0x10/0x10 [cifs] cifs_demultiplex_thread+0x692/0x1570 [cifs] ? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs] ? rcu_is_watching+0x20/0x50 ? rcu_lockdep_current_cpu_online+0x62/0xb0 ? find_held_lock+0x32/0x90 ? kvm_sched_clock_read+0x11/0x20 ? local_clock_noinstr+0xd/0xd0 ? trace_irq_enable.constprop.0+0xa8/0xe0 ? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs] kthread+0x1fe/0x380 ? kthread+0x10f/0x380 ? __pfx_kthread+0x10/0x10 ? local_clock_noinstr+0xd/0xd0 ? ret_from_fork+0x1b/0x60 ? local_clock+0x15/0x30 ? lock_release+0x29b/0x390 ? rcu_is_watching+0x20/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x60 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK>

Patch / fix

  • Linux Linux 5.11, 5.16, 6.1.191, 6.12, 6.12.24, 6.13.12, 6.14.3, 6.15
  • linux Debian 14, Debian 13 6.12.25-1

debian advisories DEBIAN-CVE-2025-37750

  • linux Ubuntu 24.04 LTS 6.8.0-64.67
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1032.34
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1033.35
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1028.32
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1029.29
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1034.39
  • linux-gkeop Ubuntu 24.04 LTS 6.8.0-1015.17
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1031.35

ubuntu advisories UBUNTU-CVE-2025-37750

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_0-570_17_1 RHEL 9 1-2.el9_6
  • kernel RHEL 9 5.14.0-570.22.1.el9_6
  • rv RHEL 9 5.14.0-570.22.1.el9_6
  • perf RHEL 9 5.14.0-570.22.1.el9_6
  • rtla RHEL 9 5.14.0-570.22.1.el9_6
  • libperf RHEL 9 5.14.0-570.22.1.el9_6
  • kernel-rt RHEL 9 5.14.0-570.22.1.el9_6
  • kernel-64k RHEL 9 5.14.0-570.22.1.el9_6

red hat advisories RHSA-2025:9393RHSA-2025:9080RHSA-2025:9079

  • dtb-aarch64 openSUSE Leap 15.6 6.4.0-150600.23.53.1
  • kernel-64kb SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 6.4.0-150600.23.53.1
  • kernel-syms SLE Module for Development Tools 15 SP6, openSUSE Leap 15.6 6.4.0-150600.23.53.1
  • kernel-obs-qa openSUSE Leap 15.6 6.4.0-150600.23.53.1
  • kernel-source SLE Module for Development Tools 15 SP6, SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 6.4.0-150600.23.53.1
  • kernel-default SLE Workstation Extension 15 SP6, SLE Module for Legacy 15 SP6, SLE Module for Basesystem 15 SP6 +3 more 6.4.0-150600.23.53.1
  • kernel-kvmsmall openSUSE Leap 15.6 6.4.0-150600.23.53.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 6.4.0-150600.23.53.1

suse advisories SUSE-SU-2025:02000-1SUSE-SU-2025:01972-1SUSE-SU-2025:20413-1SUSE-SU-2025:01967-1SUSE-SU-2025:01965-1SUSE-SU-2025:01964-1

  • kernel AlmaLinux 9 5.14.0-570.22.1.el9_6
  • rv AlmaLinux 9 5.14.0-570.22.1.el9_6
  • perf AlmaLinux 9 5.14.0-570.22.1.el9_6
  • rtla AlmaLinux 9 5.14.0-570.22.1.el9_6
  • libperf AlmaLinux 9 5.14.0-570.22.1.el9_6
  • kernel-rt AlmaLinux 9 5.14.0-570.22.1.el9_6
  • kernel-64k AlmaLinux 9 5.14.0-570.22.1.el9_6
  • kernel-core AlmaLinux 9 5.14.0-570.22.1.el9_6

almalinux advisories ALSA-2025:9080

  • kernel Rocky Linux 10 6.12.0-55.17.1.el10_0

rocky linux advisories RLSA-2025:9079

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-2025-37750 updated cvss 7.3

kernel: smb: client: fix UAF in decryption with multichannel

  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-570.22.1.el9_6, perf 5.14.0-570.22.1.el9_6, rtla 5.14.0-570.22.1.el9_6, python3-perf 5.14.0-570.22.1.el9_6, kernel-devel-matched 5.14.0-570.22.1.el9_6, kernel-64k-devel-matched 5.14.0-570.22.1.el9_6, +7 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2025:9080
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-55.17.1.el10_0, perf 6.12.0-55.17.1.el10_0, rtla 6.12.0-55.17.1.el10_0, python3-perf 6.12.0-55.17.1.el10_0, kernel-devel-matched 6.12.0-55.17.1.el10_0, kernel-64k-devel-matched 6.12.0-55.17.1.el10_0, +7 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2025:9079
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-570.22.1.el9_6, kernel-64k 5.14.0-570.22.1.el9_6, kernel-core 5.14.0-570.22.1.el9_6, kernel-tools 5.14.0-570.22.1.el9_6, kernel-modules 5.14.0-570.22.1.el9_6, kernel-64k-core 5.14.0-570.22.1.el9_6, +28 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2025:9080
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-55.17.1.el10_0, kernel-64k 6.12.0-55.17.1.el10_0, kernel-core 6.12.0-55.17.1.el10_0, kernel-tools 6.12.0-55.17.1.el10_0, kernel-modules 6.12.0-55.17.1.el10_0, kernel-64k-core 6.12.0-55.17.1.el10_0, +27 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2025:9079
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-570.22.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.22.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.22.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.22.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.22.1.el9_6
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2025:9080
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-55.17.1.el10_0, kernel-debuginfo-common-s390x 6.12.0-55.17.1.el10_0, kernel-debuginfo-common-x86_64 6.12.0-55.17.1.el10_0, kernel-debuginfo-common-aarch64 6.12.0-55.17.1.el10_0, kernel-debuginfo-common-ppc64le 6.12.0-55.17.1.el10_0
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2025:9079
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-570.22.1.el9_6, kernel-rt-64k 5.14.0-570.22.1.el9_6, kernel-rt-core 5.14.0-570.22.1.el9_6, kernel-rt-modules 5.14.0-570.22.1.el9_6, kernel-rt-64k-core 5.14.0-570.22.1.el9_6, kernel-rt-debug-core 5.14.0-570.22.1.el9_6, +14 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2025:9080
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-55.17.1.el10_0, kernel-rt-64k 6.12.0-55.17.1.el10_0, kernel-rt-core 6.12.0-55.17.1.el10_0, kernel-rt-modules 6.12.0-55.17.1.el10_0, kernel-rt-64k-core 6.12.0-55.17.1.el10_0, kernel-rt-debug-core 6.12.0-55.17.1.el10_0, +14 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2025:9079
show 3 more
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-570.22.1.el9_6, kernel-rt-kvm 5.14.0-570.22.1.el9_6, kernel-rt-core 5.14.0-570.22.1.el9_6, kernel-rt-modules 5.14.0-570.22.1.el9_6, kernel-rt-debug-kvm 5.14.0-570.22.1.el9_6, kernel-rt-debug-core 5.14.0-570.22.1.el9_6, +6 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2025:9080
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-55.17.1.el10_0, kernel-rt-kvm 6.12.0-55.17.1.el10_0, kernel-rt-core 6.12.0-55.17.1.el10_0, kernel-rt-modules 6.12.0-55.17.1.el10_0, kernel-rt-debug-kvm 6.12.0-55.17.1.el10_0, kernel-rt-debug-core 6.12.0-55.17.1.el10_0, +6 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2025:9079
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more 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 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    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

0.50% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 9.8 CVSS:3.1/AV:N/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.