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CVE Record

CVE-2024-26675: ppp_async: limit MRU to 64K

In the Linux kernel, the following vulnerability has been resolved: ppp_async: limit MRU to 64K syzbot triggered a warning [1] in __alloc_pages(): WARN_ON_ONCE_GFP(order > MAX_PAGE_ORDER, gfp) Willem fixed a similar issue in commit c0a2a1b0d631 ("ppp: limit MRU to 64K") Adopt the same sanity check for ppp_async_ioctl(PPPIOCSMRU) [1]: WARNING: CPU: 1 PID: 11 at mm/page_alloc.c:4543 __alloc_pages+0x308/0x698 mm/page_alloc.c:4543 Modules linked in: CPU: 1 PID: 11 Comm: kworker/u4:0 Not tainted 6.8.0-rc2-syzkaller-g41bccc98fb79 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: events_unbound flush_to_ldisc pstate: 204000c5 (nzCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __alloc_pages+0x308/0x698 mm/page_alloc.c:4543 lr : __alloc_pages+0xc8/0x698 mm/page_alloc.c:4537 sp : ffff800093967580 x29: ffff800093967660 x28: ffff8000939675a0 x27: dfff800000000000 x26: ffff70001272ceb4 x25: 0000000000000000 x24: ffff8000939675c0 x23: 0000000000000000 x22: 0000000000060820 x21: 1ffff0001272ceb8 x20: ffff8000939675e0 x19: 0000000000000010 x18: ffff800093967120 x17: ffff800083bded5c x16: ffff80008ac97500 x15: 0000000000000005 x14: 1ffff0001272cebc x13: 0000000000000000 x12: 0000000000000000 x11: ffff70001272cec1 x10: 1ffff0001272cec0 x9 : 0000000000000001 x8 : ffff800091c91000 x7 : 0000000000000000 x6 : 000000000000003f x5 : 00000000ffffffff x4 : 0000000000000000 x3 : 0000000000000020 x2 : 0000000000000008 x1 : 0000000000000000 x0 : ffff8000939675e0 Call trace: __alloc_pages+0x308/0x698 mm/page_alloc.c:4543 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] __kmalloc_large_node+0xbc/0x1fc mm/slub.c:3926 __do_kmalloc_node mm/slub.c:3969 [inline] __kmalloc_node_track_caller+0x418/0x620 mm/slub.c:4001 kmalloc_reserve+0x17c/0x23c net/core/skbuff.c:590 __alloc_skb+0x1c8/0x3d8 net/core/skbuff.c:651 __netdev_alloc_skb+0xb8/0x3e8 net/core/skbuff.c:715 netdev_alloc_skb include/linux/skbuff.h:3235 [inline] dev_alloc_skb include/linux/skbuff.h:3248 [inline] ppp_async_input drivers/net/ppp/ppp_async.c:863 [inline] ppp_asynctty_receive+0x588/0x186c drivers/net/ppp/ppp_async.c:341 tty_ldisc_receive_buf+0x12c/0x15c drivers/tty/tty_buffer.c:390 tty_port_default_receive_buf+0x74/0xac drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:444 [inline] flush_to_ldisc+0x284/0x6e4 drivers/tty/tty_buffer.c:494 process_one_work+0x694/0x1204 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x938/0xef4 kernel/workqueue.c:2787 kthread+0x288/0x310 kernel/kthread.c:388 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2024-26675 is a Linux kernel PPP async bug where an excessively large receive size can drive oversized memory allocation. The public record shows a syzbot-triggered kernel warning, not confirmed real-world compromise. Business urgency depends on whether systems use PPP async networking and whether vendor kernels include the stable fix.

Executive priority

Treat as a targeted kernel maintenance item, not an emergency from the provided evidence. Patch through normal kernel security update processes, with higher priority for systems that rely on PPP async connectivity.

Technical view

The issue is in drivers/net/ppp/ppp_async.c. ppp_async_ioctl(PPPIOCSMRU) lacked the MRU sanity limit already added elsewhere in PPP. The fix limits MRU to 64K, preventing ppp_async_input from reaching an oversized skb allocation path that triggered __alloc_pages warnings.

Likely exposure

Exposure appears limited to Linux systems with PPP async functionality reachable or configured. The source bundle does not define attacker prerequisites, remote reachability, privilege requirements, or impact beyond the observed allocation warning.

Exploitation context

CISA KEV status is false, and the provided sources do not report active exploitation or public weaponization. The issue was identified by syzbot against Linux 6.8-rc2-era code.

Researcher notes

The record provides a kernel warning trace and stable backport links, but no CVSS, CWE, exploit status, or complete attacker model. Analysis should remain conservative until vendor advisories clarify impact and prerequisites.

Mitigation direction

  • Apply vendor Linux kernel updates containing the ppp_async 64K MRU limit.
  • Review Debian LTS advisories if running Debian-packaged kernels.
  • Check Linux stable commit references for the relevant maintained kernel branch.
  • Prioritize systems using PPP async or PPP over TTY paths.
  • If patch status is unclear, follow the distribution vendor’s security guidance.

Validation and detection

  • Identify Linux kernel versions and vendor package backport status.
  • Confirm the ppp_async MRU limit is present in the installed kernel source or changelog.
  • Inventory systems using PPP async functionality before ranking exposure.
  • Check vendor advisories for fixed package versions covering CVE-2024-26675.
  • Document whether PPP async is enabled, loaded, or operationally required.
Prepared
Confidence
medium
Sources
12

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

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CVE-2024-26675 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
2ADP providers
11Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2unaffected
LinuxLinux2.6.12, 0, 4.19.307, 5.4.269, 5.10.210, 5.15.149, 6.1.78, 6.6.17, 6.7.5, 6.8affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.