// For flags

CVE-2024-35841

net: tls, fix WARNIING in __sk_msg_free

Severity Score

"-"
*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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

net: tls, fix WARNIING in __sk_msg_free

A splice with MSG_SPLICE_PAGES will cause tls code to use the
tls_sw_sendmsg_splice path in the TLS sendmsg code to move the user
provided pages from the msg into the msg_pl. This will loop over the
msg until msg_pl is full, checked by sk_msg_full(msg_pl). The user
can also set the MORE flag to hint stack to delay sending until receiving
more pages and ideally a full buffer.

If the user adds more pages to the msg than can fit in the msg_pl
scatterlist (MAX_MSG_FRAGS) we should ignore the MORE flag and send
the buffer anyways.

What actually happens though is we abort the msg to msg_pl scatterlist
setup and then because we forget to set 'full record' indicating we
can no longer consume data without a send we fallthrough to the 'continue'
path which will check if msg_data_left(msg) has more bytes to send and
then attempts to fit them in the already full msg_pl. Then next
iteration of sender doing send will encounter a full msg_pl and throw
the warning in the syzbot report.

To fix simply check if we have a full_record in splice code path and
if not send the msg regardless of MORE flag.

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: net: tls, corrija la ADVERTENCIA en __sk_msg_free Un empalme con MSG_SPLICE_PAGES hará que el código tls use la ruta tls_sw_sendmsg_splice en el código TLS sendmsg para mover las páginas proporcionadas por el usuario del msg al msg_pl . Esto recorrerá el mensaje hasta que msg_pl esté lleno, verificado por sk_msg_full(msg_pl). El usuario también puede configurar el indicador MORE para que la pila de sugerencias retrase el envío hasta recibir más páginas e idealmente un búfer completo. Si el usuario agrega más páginas al mensaje de las que caben en la lista de dispersión msg_pl (MAX_MSG_FRAGS), debemos ignorar el indicador MÁS y enviar el búfer de todos modos. Sin embargo, lo que realmente sucede es que abortamos la configuración de la lista de dispersión de msg a msg_pl y luego, como nos olvidamos de configurar el 'registro completo', lo que indica que ya no podemos consumir datos sin un envío, pasamos a la ruta 'continuar' que verificará si msg_data_left(msg) tiene más bytes para enviar y luego intenta incluirlos en el msg_pl que ya está completo. Luego, la próxima iteración del remitente que realiza el envío encontrará un msg_pl completo y arrojará la advertencia en el informe syzbot. Para solucionarlo, simplemente verifique si tenemos un registro completo en la ruta del código de empalme y, si no, envíe el mensaje independientemente del indicador MORE.

*Credits: N/A
CVSS Scores
Attack Vector
-
Attack Complexity
-
Privileges Required
-
User Interaction
-
Scope
-
Confidentiality
-
Integrity
-
Availability
-
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-05-17 CVE Reserved
  • 2024-05-17 CVE Published
  • 2024-05-18 EPSS Updated
  • 2024-09-11 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 6.5 < 6.6.14
Search vendor "Linux" for product "Linux Kernel" and version " >= 6.5 < 6.6.14"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 6.5 < 6.7.2
Search vendor "Linux" for product "Linux Kernel" and version " >= 6.5 < 6.7.2"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 6.5 < 6.8
Search vendor "Linux" for product "Linux Kernel" and version " >= 6.5 < 6.8"
en
Affected