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In the Linux kernel, the following vulnerability has been...

High severity Unreviewed Published May 1, 2025 to the GitHub Advisory Database • Updated Nov 7, 2025

Package

No package listed— Suggest a package

Affected versions

Unknown

Patched versions

Unknown

Description

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:

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

References

Published by the National Vulnerability Database May 1, 2025
Published to the GitHub Advisory Database May 1, 2025
Last updated Nov 7, 2025

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(4th percentile)

Weaknesses

Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer. Learn more on MITRE.

CVE ID

CVE-2025-37750

GHSA ID

GHSA-r3p6-jggx-m3qg

Source code

No known source code

Dependabot alerts are not supported on this advisory because it does not have a package from a supported ecosystem with an affected and fixed version.

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