CVE-2023-53599

crypto: af_alg - Fix missing initialisation affecting gcm-aes-s390

Published Oct 4, 2025 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

crypto: af_alg - Fix missing initialisation affecting gcm-aes-s390

Fix af_alg_alloc_areq() to initialise areq->first_rsgl.sgl.sgt.sgl to point
to the scatterlist array in areq->first_rsgl.sgl.sgl.

Without this, the gcm-aes-s390 driver will oops when it tries to do
gcm_walk_start() on req->dst because req->dst is set to the value of
areq->first_rsgl.sgl.sgl by _aead_recvmsg() calling
aead_request_set_crypt().

The problem comes if an empty ciphertext is passed: the loop in
af_alg_get_rsgl() just passes straight out and doesn't set areq->first_rsgl
up.

This isn't a problem on x86_64 using gcmaes_crypt_by_sg() because, as far
as I can tell, that ignores req->dst and only uses req->src[*].

[*] Is this a bug in aesni-intel_glue.c?

The s390x oops looks something like:

Unable to handle kernel pointer dereference in virtual kernel address space
Failing address: 0000000a00000000 TEID: 0000000a00000803
Fault in home space mode while using kernel ASCE.
AS:00000000a43a0007 R3:0000000000000024
Oops: 003b ilc:2 [#1] SMP
...
Call Trace:
[<000003ff7fc3d47e>] gcm_walk_start+0x16/0x28 [aes_s390]
[<00000000a2a342f2>] crypto_aead_decrypt+0x9a/0xb8
[<00000000a2a60888>] aead_recvmsg+0x478/0x698
[<00000000a2e519a0>] sock_recvmsg+0x70/0xb0
[<00000000a2e51a56>] sock_read_iter+0x76/0xa0
[<00000000a273e066>] vfs_read+0x26e/0x2a8
[<00000000a273e8c4>] ksys_read+0xbc/0x100
[<00000000a311d808>] __do_syscall+0x1d0/0x1f8
[<00000000a312ff30>] system_call+0x70/0x98
Last Breaking-Event-Address:
[<000003ff7fc3e6b4>] gcm_aes_crypt+0x104/0xa68 [aes_s390]

Analysis

No analysis available yet

Remediation

No remediation available yet

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2023-60009 In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Fix missing initialisation affecting gcm-aes-s390 Fix af_alg_alloc_areq() to initialise areq->first_rsgl.sgl.sgt.sgl to point to the scatterlist array in areq->first_rsgl.sgl.sgl. Without this, the gcm-aes-s390 driver will oops when it tries to do gcm_walk_start() on req->dst because req->dst is set to the value of areq->first_rsgl.sgl.sgl by _aead_recvmsg() calling aead_request_set_crypt(). The problem comes if an empty ciphertext is passed: the loop in af_alg_get_rsgl() just passes straight out and doesn't set areq->first_rsgl up. This isn't a problem on x86_64 using gcmaes_crypt_by_sg() because, as far as I can tell, that ignores req->dst and only uses req->src[*]. [*] Is this a bug in aesni-intel_glue.c? The s390x oops looks something like: Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 0000000a00000000 TEID: 0000000a00000803 Fault in home space mode while using kernel ASCE. AS:00000000a43a0007 R3:0000000000000024 Oops: 003b ilc:2 [#1] SMP ... Call Trace: [<000003ff7fc3d47e>] gcm_walk_start+0x16/0x28 [aes_s390] [<00000000a2a342f2>] crypto_aead_decrypt+0x9a/0xb8 [<00000000a2a60888>] aead_recvmsg+0x478/0x698 [<00000000a2e519a0>] sock_recvmsg+0x70/0xb0 [<00000000a2e51a56>] sock_read_iter+0x76/0xa0 [<00000000a273e066>] vfs_read+0x26e/0x2a8 [<00000000a273e8c4>] ksys_read+0xbc/0x100 [<00000000a311d808>] __do_syscall+0x1d0/0x1f8 [<00000000a312ff30>] system_call+0x70/0x98 Last Breaking-Event-Address: [<000003ff7fc3e6b4>] gcm_aes_crypt+0x104/0xa68 [aes_s390]
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Weaknesses CWE-476
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel
Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Fix missing initialisation affecting gcm-aes-s390 Fix af_alg_alloc_areq() to initialise areq->first_rsgl.sgl.sgt.sgl to point to the scatterlist array in areq->first_rsgl.sgl.sgl. Without this, the gcm-aes-s390 driver will oops when it tries to do gcm_walk_start() on req->dst because req->dst is set to the value of areq->first_rsgl.sgl.sgl by _aead_recvmsg() calling aead_request_set_crypt(). The problem comes if an empty ciphertext is passed: the loop in af_alg_get_rsgl() just passes straight out and doesn't set areq->first_rsgl up. This isn't a problem on x86_64 using gcmaes_crypt_by_sg() because, as far as I can tell, that ignores req->dst and only uses req->src[*]. [*] Is this a bug in aesni-intel_glue.c? The s390x oops looks something like: Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 0000000a00000000 TEID: 0000000a00000803 Fault in home space mode while using kernel ASCE. AS:00000000a43a0007 R3:0000000000000024 Oops: 003b ilc:2 [#1] SMP ... Call Trace: [<000003ff7fc3d47e>] gcm_walk_start+0x16/0x28 [aes_s390] [<00000000a2a342f2>] crypto_aead_decrypt+0x9a/0xb8 [<00000000a2a60888>] aead_recvmsg+0x478/0x698 [<00000000a2e519a0>] sock_recvmsg+0x70/0xb0 [<00000000a2e51a56>] sock_read_iter+0x76/0xa0 [<00000000a273e066>] vfs_read+0x26e/0x2a8 [<00000000a273e8c4>] ksys_read+0xbc/0x100 [<00000000a311d808>] __do_syscall+0x1d0/0x1f8 [<00000000a312ff30>] system_call+0x70/0x98 Last Breaking-Event-Address: [<000003ff7fc3e6b4>] gcm_aes_crypt+0x104/0xa68 [aes_s390]
Title crypto: af_alg - Fix missing initialisation affecting gcm-aes-s390
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Aug 5, 2026, 9:15 AM
Reserved
Oct 4, 2025, 3:40 PM
Status
Modified
Published
Oct 4, 2025, 4:15 PM
Modified
Aug 4, 2026, 10:19 AM
Severity
Moderate
Public date
Oct 4, 2025, 12:00 AM