CyberAlerts is shutting down on June 30th, 2025. Thank you for your support!

CVE-2024-50035: ppp: fix ppp_async_encode() illegal access

7.1 CVSS

Description

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

ppp: fix ppp_async_encode() illegal access

syzbot reported an issue in ppp_async_encode() [1]

In this case, pppoe_sendmsg() is called with a zero size.
Then ppp_async_encode() is called with an empty skb.

BUG: KMSAN: uninit-value in ppp_async_encode drivers/net/ppp/ppp_async.c:545 [inline]
BUG: KMSAN: uninit-value in ppp_async_push+0xb4f/0x2660 drivers/net/ppp/ppp_async.c:675
ppp_async_encode drivers/net/ppp/ppp_async.c:545 [inline]
ppp_async_push+0xb4f/0x2660 drivers/net/ppp/ppp_async.c:675
ppp_async_send+0x130/0x1b0 drivers/net/ppp/ppp_async.c:634
ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2280 [inline]
ppp_input+0x1f1/0xe60 drivers/net/ppp/ppp_generic.c:2304
pppoe_rcv_core+0x1d3/0x720 drivers/net/ppp/pppoe.c:379
sk_backlog_rcv+0x13b/0x420 include/net/sock.h:1113
__release_sock+0x1da/0x330 net/core/sock.c:3072
release_sock+0x6b/0x250 net/core/sock.c:3626
pppoe_sendmsg+0x2b8/0xb90 drivers/net/ppp/pppoe.c:903
sock_sendmsg_nosec net/socket.c:729 [inline]
__sock_sendmsg+0x30f/0x380 net/socket.c:744
____sys_sendmsg+0x903/0xb60 net/socket.c:2602
___sys_sendmsg+0x28d/0x3c0 net/socket.c:2656
__sys_sendmmsg+0x3c1/0x960 net/socket.c:2742
__do_sys_sendmmsg net/socket.c:2771 [inline]
__se_sys_sendmmsg net/socket.c:2768 [inline]
__x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2768
x64_sys_call+0xb6e/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:308
do_syscall_...

Classification

CVE ID: CVE-2024-50035

CVSS Base Severity: HIGH

CVSS Base Score: 7.1

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.03% (probability of being exploited)

EPSS Percentile: 6.84% (scored less or equal to compared to others)

EPSS Date: 2025-06-02 (when was this score calculated)

Stakeholder-Specific Vulnerability Categorization (SSVC)

SSVC Exploitation: none

SSVC Technical Impact: partial

SSVC Automatable: false

References

Timeline

2025-05-04 10:40:21 UTC
CVE

ppp: fix ppp_async_encode() illegal access