critical 9.8

CVE-2024-50047 in the critical feed json

smb: client: fix UAF in async decryption

published 2024-10-21 2 y ago modified 2026-08-05 3 mo ago also EUVD-2024-44763

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 44%
public exploits: 0; none known

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

Doing an async decryption (large read) crashes with a slab-use-after-free way down in the crypto API.

Reproducer: # mount.cifs -o ...,seal,esize=1 //srv/share /mnt # dd if=/mnt/largefile of=/dev/null ... [ 194.196391] ================================================================== [ 194.196844] BUG: KASAN: slab-use-after-free in gf128mul_4k_lle+0xc1/0x110 [ 194.197269] Read of size 8 at addr ffff888112bd0448 by task kworker/u77:2/899 [ 194.197707] [ 194.197818] CPU: 12 UID: 0 PID: 899 Comm: kworker/u77:2 Not tainted 6.11.0-lku-00028-gfca3ca14a17a-dirty #43 [ 194.198400] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-prebuilt.qemu.org 04/01/2014 [ 194.199046] Workqueue: smb3decryptd smb2_decrypt_offload [cifs] [ 194.200032] Call Trace: [ 194.200191] <TASK> [ 194.200327] dump_stack_lvl+0x4e/0x70 [ 194.200558] ? gf128mul_4k_lle+0xc1/0x110 [ 194.200809] print_report+0x174/0x505 [ 194.201040] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [ 194.201352] ? srso_return_thunk+0x5/0x5f [ 194.201604] ? __virt_addr_valid+0xdf/0x1c0 [ 194.201868] ? gf128mul_4k_lle+0xc1/0x110 [ 194.202128] kasan_report+0xc8/0x150 [ 194.202361] ? gf128mul_4k_lle+0xc1/0x110 [ 194.202616] gf128mul_4k_lle+0xc1/0x110 [ 194.202863] ghash_update+0x184/0x210 [ 194.203103] shash_ahash_update+0x184/0x2a0 [ 194.203377] ? __pfx_shash_ahash_update+0x10/0x10 [ 194.203651] ? srso_return_thunk+0x5/0x5f [ 194.203877] ? crypto_gcm_init_common+0x1ba/0x340 [ 194.204142] gcm_hash_assoc_remain_continue+0x10a/0x140 [ 194.204434] crypt_message+0xec1/0x10a0 [cifs] [ 194.206489] ? __pfx_crypt_message+0x10/0x10 [cifs] [ 194.208507] ? srso_return_thunk+0x5/0x5f [ 194.209205] ? srso_return_thunk+0x5/0x5f [ 194.209925] ? srso_return_thunk+0x5/0x5f [ 194.210443] ? srso_return_thunk+0x5/0x5f [ 194.211037] decrypt_raw_data+0x15f/0x250 [cifs] [ 194.212906] ? __pfx_decrypt_raw_data+0x10/0x10 [cifs] [ 194.214670] ? srso_return_thunk+0x5/0x5f [ 194.215193] smb2_decrypt_offload+0x12a/0x6c0 [cifs]

This is because TFM is being used in parallel.

Fix this by allocating a new AEAD TFM for async decryption, but keep the existing one for synchronous READ cases (similar to what is done in smb3_calc_signature()).

Also remove the calls to aead_request_set_callback() and crypto_wait_req() since it's always going to be a synchronous operation.

Patch / fix

fixed in 1 distros 6 links 6

Linux Linux 5.10.237, 5.15.181, 6.1.128, 6.6.57, 6.11.4, 6.12

debian ubuntu red hat suse opensuse azure linux

linux Debian 12 6.1.128-1
linux Debian 14, Debian 13 6.11.4-1

debian advisories DEBIAN-CVE-2024-50047

linux Ubuntu 22.04 LTS 5.15.0-143.153
linux Ubuntu 24.04 LTS 6.8.0-56.58
linux-aws Ubuntu 22.04 LTS 5.15.0-1087.94
linux-aws Ubuntu 24.04 LTS 6.8.0-1025.27
linux-gcp Ubuntu 22.04 LTS 5.15.0-1086.95
linux-gcp Ubuntu 24.04 LTS 6.8.0-1026.28
linux-gke Ubuntu 22.04 LTS 5.15.0-1084.90
linux-gke Ubuntu 24.04 LTS 6.8.0-1021.25

ubuntu advisories UBUNTU-CVE-2024-50047

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

kernel RHEL 9 5.14.0-570.12.1.el9_6
rv RHEL 9 5.14.0-570.12.1.el9_6
perf RHEL 9 5.14.0-570.12.1.el9_6
rtla RHEL 9 5.14.0-570.12.1.el9_6
libperf RHEL 9 5.14.0-570.12.1.el9_6
kernel-rt RHEL 9 5.14.0-570.12.1.el9_6
kernel-64k RHEL 9 5.14.0-570.12.1.el9_6
kernel-core RHEL 9 5.14.0-570.12.1.el9_6

red hat advisories RHSA-2025:6966

kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
kernel-livepatch-MICRO-6-0-RT_Update_5 Linux Micro 6.1, Linux Micro 6.0 1-1.1
kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
kernel-default Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
kernel-kvmsmall Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
kernel-default-base Linux Micro 6.1, Linux Micro 6.0 6.4.0-24.1.21.4
kernel-livepatch-MICRO-6-0_Update_5 Linux Micro 6.1, Linux Micro 6.0 1-1.2

suse advisories SUSE-SU-2025:20166-1 SUSE-SU-2025:20249-1 SUSE-SU-2025:20165-1 SUSE-SU-2025:20164-1 SUSE-SU-2025:20248-1 SUSE-SU-2025:20247-1

kernel-source-longterm openSUSE Tumbleweed 6.12.11-1.1
kernel-source openSUSE Tumbleweed 6.11.8-1.1

opensuse advisories openSUSE-SU-2025:14705-1 openSUSE-SU-2024:14500-1

kernel CBL-Mariner 2.0 5.15.182.1-1
kernel Azure Linux 3.0 6.6.57.1-1

azure linux advisories AZL-50767 AZL-50936

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2024-50047 updated 2026-11-05 cvss 6.7

kernel: smb: client: fix UAF in async decryption

Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-570.12.1.el9_6, perf 5.14.0-570.12.1.el9_6, rtla 5.14.0-570.12.1.el9_6, python3-perf 5.14.0-570.12.1.el9_6, kernel-devel-matched 5.14.0-570.12.1.el9_6, kernel-64k-devel-matched 5.14.0-570.12.1.el9_6, +7 more Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-570.12.1.el9_6, kernel-64k 5.14.0-570.12.1.el9_6, kernel-core 5.14.0-570.12.1.el9_6, kernel-tools 5.14.0-570.12.1.el9_6, kernel-modules 5.14.0-570.12.1.el9_6, kernel-64k-core 5.14.0-570.12.1.el9_6, +27 more Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.12.1.el9_6 Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-570.12.1.el9_6, kernel-rt-64k 5.14.0-570.12.1.el9_6, kernel-rt-core 5.14.0-570.12.1.el9_6, kernel-rt-modules 5.14.0-570.12.1.el9_6, kernel-rt-64k-core 5.14.0-570.12.1.el9_6, kernel-rt-debug-core 5.14.0-570.12.1.el9_6, +14 more Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-570.12.1.el9_6, kernel-rt-kvm 5.14.0-570.12.1.el9_6, kernel-rt-core 5.14.0-570.12.1.el9_6, kernel-rt-modules 5.14.0-570.12.1.el9_6, kernel-rt-debug-kvm 5.14.0-570.12.1.el9_6, kernel-rt-debug-core 5.14.0-570.12.1.el9_6, +6 more
fixed: vendor fix RHSA-2025:6966
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
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: 2 y ago (2024-10-22)

Exploit prediction

0.52% chance of exploitation in the next 30 days, higher than 44% 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

CWE-416 Use After Free

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2024-50047
NVD CVE-2024-50047

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.

Summary