// For flags

CVE-2024-38596

af_unix: Fix data races in unix_release_sock/unix_stream_sendmsg

Severity Score

4.7
*CVSS v3.1

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:

af_unix: Fix data races in unix_release_sock/unix_stream_sendmsg

A data-race condition has been identified in af_unix. In one data path,
the write function unix_release_sock() atomically writes to
sk->sk_shutdown using WRITE_ONCE. However, on the reader side,
unix_stream_sendmsg() does not read it atomically. Consequently, this
issue is causing the following KCSAN splat to occur:

BUG: KCSAN: data-race in unix_release_sock / unix_stream_sendmsg

write (marked) to 0xffff88867256ddbb of 1 bytes by task 7270 on cpu 28:
unix_release_sock (net/unix/af_unix.c:640)
unix_release (net/unix/af_unix.c:1050)
sock_close (net/socket.c:659 net/socket.c:1421)
__fput (fs/file_table.c:422)
__fput_sync (fs/file_table.c:508)
__se_sys_close (fs/open.c:1559 fs/open.c:1541)
__x64_sys_close (fs/open.c:1541)
x64_sys_call (arch/x86/entry/syscall_64.c:33)
do_syscall_64 (arch/x86/entry/common.c:?)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

read to 0xffff88867256ddbb of 1 bytes by task 989 on cpu 14:
unix_stream_sendmsg (net/unix/af_unix.c:2273)
__sock_sendmsg (net/socket.c:730 net/socket.c:745)
____sys_sendmsg (net/socket.c:2584)
__sys_sendmmsg (net/socket.c:2638 net/socket.c:2724)
__x64_sys_sendmmsg (net/socket.c:2753 net/socket.c:2750 net/socket.c:2750)
x64_sys_call (arch/x86/entry/syscall_64.c:33)
do_syscall_64 (arch/x86/entry/common.c:?)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

value changed: 0x01 -> 0x03

The line numbers are related to commit dd5a440a31fa ("Linux 6.9-rc7").

Commit e1d09c2c2f57 ("af_unix: Fix data races around sk->sk_shutdown.")
addressed a comparable issue in the past regarding sk->sk_shutdown.
However, it overlooked resolving this particular data path.
This patch only offending unix_stream_sendmsg() function, since the
other reads seem to be protected by unix_state_lock() as discussed in

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: af_unix: corrige ejecucións de datos en unix_release_sock/unix_stream_sendmsg Se identificó una condición de ejecución de datos en af_unix. En una ruta de datos, la función de escritura unix_release_sock() escribe atómicamente en sk->sk_shutdown usando WRITE_ONCE. Sin embargo, en el lado del lector, unix_stream_sendmsg() no lo lee atómicamente. En consecuencia, este problema está provocando que se produzca el siguiente símbolo de KCSAN: ERROR: KCSAN: data-race en unix_release_sock / unix_stream_sendmsg escribe (marcado) en 0xffff88867256ddbb de 1 byte por tarea 7270 en la CPU 28: unix_release_sock (net/unix/af_unix.c: 640) unix_release (net/unix/af_unix.c:1050) sock_close (net/socket.c:659 net/socket.c:1421) __fput (fs/file_table.c:422) __fput_sync (fs/file_table.c:508 ) __se_sys_close (fs/open.c:1559 fs/open.c:1541) __x64_sys_close (fs/open.c:1541) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/ common.c:?) Entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) leído en 0xffff88867256ddbb de 1 bytes por la tarea 989 en la CPU 14: unix_stream_sendmsg (net/unix/af_unix.c:2273) __sock_sendmsg (net/socket .c:730 net/socket.c:745) ____sys_sendmsg (net/socket.c:2584) __sys_sendmmsg (net/socket.c:2638 net/socket.c:2724) __x64_sys_sendmmsg (net/socket.c:2753 net/ socket.c:2750 net/socket.c:2750) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) Entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64 .S:130) valor cambiado: 0x01 -> 0x03 Los números de línea están relacionados con el commit dd5a440a31fa ("Linux 6.9-rc7"). El commit e1d09c2c2f57 ("af_unix: corregir ejecucións de datos alrededor de sk->sk_shutdown.") abordó un problema comparable en el pasado con respecto a sk->sk_shutdown. Sin embargo, pasó por alto resolver esta ruta de datos en particular. Este parche solo ofende la función unix_stream_sendmsg(), ya que las otras lecturas parecen estar protegidas por unix_state_lock() como se explica en

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-06-18 CVE Reserved
  • 2024-06-19 CVE Published
  • 2024-06-20 EPSS Updated
  • 2024-09-11 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
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"
>= 2.6.12 < 4.19.316
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 4.19.316"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 5.4.278
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 5.4.278"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 5.10.219
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 5.10.219"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 5.15.161
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 5.15.161"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 6.1.93
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 6.1.93"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 6.6.33
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 6.6.33"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 6.8.12
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 6.8.12"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 6.9.3
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 6.9.3"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 6.10
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 6.10"
en
Affected