In the Linux kernel, the following vulnerability has been resolved:
tls: fix handling of zero-length records on the rx_list
Each recvmsg() call must process either
- only contiguous DATA records (any number of them)
- one non-DATA record
If the next record has different type than what has already been
processed we break out of the main processing loop. If the record
has already been decrypted (which may be the case for TLS 1.3 where
we don't know type until decryption) we queue the pending record
to the rx_list. Next recvmsg() will pick it up from there.
Queuing the skb to rx_list after zero-copy decrypt is not possible,
since in that case we decrypted directly to the user space buffer,
and we don't have an skb to queue (darg.skb points to the ciphertext
skb for access to metadata like length).
Only data records are allowed zero-copy, and we break the processing
loop after each non-data record. So we should never zero-copy and
then find out that the record type has changed. The corner case
we missed is when the initial record comes from rx_list, and it's
zero length.
tls: fix handling of zero-length records on the rx_list
Each recvmsg() call must process either
- only contiguous DATA records (any number of them)
- one non-DATA record
If the next record has different type than what has already been
processed we break out of the main processing loop. If the record
has already been decrypted (which may be the case for TLS 1.3 where
we don't know type until decryption) we queue the pending record
to the rx_list. Next recvmsg() will pick it up from there.
Queuing the skb to rx_list after zero-copy decrypt is not possible,
since in that case we decrypted directly to the user space buffer,
and we don't have an skb to queue (darg.skb points to the ciphertext
skb for access to metadata like length).
Only data records are allowed zero-copy, and we break the processing
loop after each non-data record. So we should never zero-copy and
then find out that the record type has changed. The corner case
we missed is when the initial record comes from rx_list, and it's
zero length.
Metrics
Affected Vendors & Products
Advisories
| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4328-1 | linux-6.1 security update |
Debian DSA |
DSA-6008-1 | linux security update |
Debian DSA |
DSA-6009-1 | linux security update |
EUVD |
EUVD-2025-31542 | In the Linux kernel, the following vulnerability has been resolved: tls: fix handling of zero-length records on the rx_list Each recvmsg() call must process either - only contiguous DATA records (any number of them) - one non-DATA record If the next record has different type than what has already been processed we break out of the main processing loop. If the record has already been decrypted (which may be the case for TLS 1.3 where we don't know type until decryption) we queue the pending record to the rx_list. Next recvmsg() will pick it up from there. Queuing the skb to rx_list after zero-copy decrypt is not possible, since in that case we decrypted directly to the user space buffer, and we don't have an skb to queue (darg.skb points to the ciphertext skb for access to metadata like length). Only data records are allowed zero-copy, and we break the processing loop after each non-data record. So we should never zero-copy and then find out that the record type has changed. The corner case we missed is when the initial record comes from rx_list, and it's zero length. |
Ubuntu USN |
USN-7833-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7834-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-7833-2 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-7835-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7835-2 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-7835-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7833-3 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-7833-4 | Linux kernel (GCP) vulnerabilities |
Ubuntu USN |
USN-7835-4 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-7856-1 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-7835-5 | Linux kernel (Oracle) vulnerabilities |
Ubuntu USN |
USN-7835-6 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-7887-1 | Linux kernel (Raspberry Pi Real-time) vulnerabilities |
Ubuntu USN |
USN-7887-2 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-7940-1 | Linux kernel (Azure FIPS) vulnerabilities |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Mon, 03 Nov 2025 18:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Sat, 06 Sep 2025 09:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Vendors & Products |
Linux
Linux linux Kernel |
Sat, 06 Sep 2025 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Fri, 05 Sep 2025 17:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: tls: fix handling of zero-length records on the rx_list Each recvmsg() call must process either - only contiguous DATA records (any number of them) - one non-DATA record If the next record has different type than what has already been processed we break out of the main processing loop. If the record has already been decrypted (which may be the case for TLS 1.3 where we don't know type until decryption) we queue the pending record to the rx_list. Next recvmsg() will pick it up from there. Queuing the skb to rx_list after zero-copy decrypt is not possible, since in that case we decrypted directly to the user space buffer, and we don't have an skb to queue (darg.skb points to the ciphertext skb for access to metadata like length). Only data records are allowed zero-copy, and we break the processing loop after each non-data record. So we should never zero-copy and then find out that the record type has changed. The corner case we missed is when the initial record comes from rx_list, and it's zero length. | |
| Title | tls: fix handling of zero-length records on the rx_list | |
| References |
|
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-11-03T17:42:13.673Z
Reserved: 2025-04-16T07:20:57.113Z
Link: CVE-2025-39682
No data.
Status : Awaiting Analysis
Published: 2025-09-05T18:15:44.670
Modified: 2025-11-03T18:16:38.987
Link: CVE-2025-39682
OpenCVE Enrichment
Updated: 2025-09-06T09:01:37Z
Weaknesses
No weakness.
Debian DLA
Debian DSA
EUVD
Ubuntu USN