PT-2025-34399 · Linux+1 · Linux Kernel+1

Syzbot · Published 2025-07-26 · Updated 2025-08-22 · CVE-2025-38638

Positive Technologies (AI Summary)

CVSS v2.0

6.0

Medium

Base vector

AV:L/AC:H/Au:S/C:C/I:C/A:C

Name of the Vulnerable Software and Affected Versions: Linux kernel versions prior to 6.16.0-rc7-syzkaller

Description: The Linux kernel contained a flaw in the inet6 rt notify() function within the IPv6 networking stack. Specifically, the function could be called while under RCU protection, potentially leading to a race condition where a route could change concurrently with the function's execution. This could result in rt6 fill node() returning an -EMSGSIZE error. The issue was addressed by adding retry logic to resize the skb when this condition occurs, removing a related warning that was triggered by syzbot.

Recommendations: Update to a version newer than 6.16.0-rc7-syzkaller.

Exploit

Fix

Improper Locking

Weakness Enumeration

CWE-667

Related Identifiers

BDU:2026-01554

CVE-2025-38638

Affected Products

Astra Linux

Linux Kernel

References · 13

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38638.json · Exploit
• https://git.kernel.org/stable/c/0bdca3439a22c70eb8f404acd61bf7aca5d731b0 · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2025-38638 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-38638 · Security Note
• https://cve.org/CVERecord?id=CVE-2025-38638 · Security Note
• https://osv.dev/vulnerability/CVE-2025-38638 · Vendor Advisory
• https://bdu.fstec.ru/vul/2026-01554 · Security Note
• https://ubuntu.com/security/CVE-2025-38638 · Vendor Advisory
• https://git.kernel.org/stable/c/ea2f921db7a483a526058c5b5b8162edd88dabe5 · Patch
• https://lore.kernel.org/linux-cve-announce/2025082234-CVE-2025-38638-caad@gregkh · Note
• https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git · Note
• https://git.kernel.org/linus/ea2f921db7a483a526058c5b5b8162edd88dabe5 · Note
• https://twitter.com/CVEnew/status/1958933916749853018 · Twitter Post