CVE-2025-40064

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Last Modified: UTC

Moderate Moderate Impact What does this mean?
7.1 CVSS v3 Base Score

Description

The MITRE CVE dictionary describes this issue as

In the Linux kernel, the following vulnerability has been resolved: smc: Fix use-after-free in __pnet_find_base_ndev(). syzbot reported use-after-free of net_device in __pnet_find_base_ndev(), which was called during connect(). [0] smc_pnet_find_ism_resource() fetches sk_dst_get(sk)->dev and passes down to pnet_find_base_ndev(), where RTNL is held. Then, UAF happened at __pnet_find_base_ndev() when the dev is first used. This means dev had already been freed before acquiring RTNL in pnet_find_base_ndev(). While dev is going away, dst->dev could be swapped with blackhole_netdev, and the dev's refcnt by dst will be released. We must hold dev's refcnt before calling smc_pnet_find_ism_resource(). Also, smc_pnet_find_roce_resource() has the same problem. Let's use __sk_dst_get() and dst_dev_rcu() in the two functions. [0]: BUG: KASAN: use-after-free in __pnet_find_base_ndev+0x1b1/0x1c0 net/smc/smc_pnet.c:926 Read of size 1 at addr ffff888036bac33a by task syz.0.3632/18609 CPU: 1 UID: 0 PID: 18609 Comm: syz.0.3632 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 __pnet_find_base_ndev+0x1b1/0x1c0 net/smc/smc_pnet.c:926 pnet_find_base_ndev net/smc/smc_pnet.c:946 [inline] smc_pnet_find_ism_by_pnetid net/smc/smc_pnet.c:1103 [inline] smc_pnet_find_ism_resource+0xef/0x390 net/smc/smc_pnet.c:1154 smc_find_ism_device net/smc/af_smc.c:1030 [inline] smc_find_proposal_devices net/smc/af_smc.c:1115 [inline] __smc_connect+0x372/0x1890 net/smc/af_smc.c:1545 smc_connect+0x877/0xd90 net/smc/af_smc.c:1715 __sys_connect_file net/socket.c:2086 [inline] __sys_connect+0x313/0x440 net/socket.c:2105 __do_sys_connect net/socket.c:2111 [inline] __se_sys_connect net/socket.c:2108 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2108 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f47cbf8eba9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f47ccdb1038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 00007f47cc1d5fa0 RCX: 00007f47cbf8eba9 RDX: 0000000000000010 RSI: 0000200000000280 RDI: 000000000000000b RBP: 00007f47cc011e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f47cc1d6038 R14: 00007f47cc1d5fa0 R15: 00007ffc512f8aa8 </TASK> The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888036bacd00 pfn:0x36bac flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001243d08 ffff8880b863fdc0 0000000000000000 raw: ffff888036bacd00 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 2, migratetype Unmovable, gfp_mask 0x446dc0(GFP_KERNEL_ACCOUNT|__GFP_ZERO|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_COMP), pid 16741, tgid 16741 (syz-executor), ts 343313197788, free_ts 380670750466 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 ___kmalloc_large_node+0x5f/0x1b0 mm/slub.c:4317 __kmalloc_large_node_noprof+0x18/0x90 mm/slub.c:4348 __do_kmalloc_node mm/slub.c:4364 [inline] __kvmalloc_node ---truncated---

Additional Information

External References

Content from www.cve.org is not included.https://www.cve.org/CVERecord?id=CVE-2025-40064

Content from nvd.nist.gov is not included.https://nvd.nist.gov/vuln/detail/CVE-2025-40064

Content from lore.kernel.org is not included.https://lore.kernel.org/linux-cve-announce/2025102817-CVE-2025-40064-0c16@gregkh/T

Affected Packages and Issued Red Hat Security Errata

Products / Services Components State Errata
Red Hat Enterprise Linux 10 kernel Fixed RHSA-2026:2721
Red Hat Enterprise Linux 10.0 Extended Update Support kernel Fixed RHSA-2026:4111
Red Hat Enterprise Linux 6 kernel Not affected
Red Hat Enterprise Linux 7 kernel Not affected
Red Hat Enterprise Linux 7 kernel-rt Not affected
Red Hat Enterprise Linux 8 kernel Fixed RHSA-2026:3083
Red Hat Enterprise Linux 8 kernel-rt Fixed RHSA-2026:3110
Red Hat Enterprise Linux 8.8 Telecommunications Update Service kernel Fixed RHSA-2026:6954
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions kernel Fixed RHSA-2026:6954
Red Hat Enterprise Linux 9 kernel-rt Affected
Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authorities (CNA) source for its products and services (see Red Hat classifications ).

CVSS v3 Score Breakdown Red Hat NVD
CVSS v3 Base Score 7.1
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality Impact High
Integrity Impact None
Availability Impact High

CVSS v3 Vector

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

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

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For more information, see https://access.redhat.com/solutions/762393.

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
  • "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
  • "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.

What can I do if my product is listed as "Will not fix"?

 A "will not fix" status means that a fix for an affected product version is not planned or not possible due to complexity, which may create additional risk.

Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
  • Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
  • Apply a mitigation (if one exists).
  • Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.

What can I do if my product is listed as "Fix deferred"?

 A deferred status means that a fix for an affected product version is not guaranteed due to higher-priority development work.

Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
  • Apply a mitigation (if one exists).
  • Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
  • Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.

What is a mitigation?

 A mitigation is an action that can be taken to reduce the impact of a security vulnerability, without deploying any fixes.

I have a Red Hat product but it is not in the above list, is it affected?

 The listed products were found to include one or more of the components that this vulnerability affects. These products underwent a thorough evaluation to determine their affectedness by this vulnerability. Note that layered products (such as container-based offerings) that consume affected components from any of the products listed in this table may be affected and are not represented.

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

 In order to maintain code stability and compatibility, Red Hat usually does not rebase packages to entirely new versions. Instead, we backport fixes and new features to an older version of the package we distribute. This can result in some security scanners that only consider the package version to report the package as vulnerable. To avoid this, we suggest that you use an approved vulnerability scanner from our This content is not included.Red Hat Vulnerability Scanner Certification program.

My product is listed as "Out of Support Scope". What does this mean?

 When a product is listed as "Out of Support Scope", it means a vulnerability with the impact level assigned to this CVE is no longer covered by its current support lifecycle phase. The product has been identified to contain the impacted component, but analysis to determine whether it is affected or not by this vulnerability was not performed. The product should be assumed to be affected. Customers are advised to apply any mitigation options documented on this page, consider removing or disabling the impacted component, or upgrade to a supported version of the product that has an update available.