Linux Kernel up to 7.0.10 Netfs subrequests/flags privilege escalation

Summaryinfo

A vulnerability identified as very critical has been detected in Linux Kernel up to 7.0.10. This vulnerability affects the function netfs_collect_read_results/netfs_collect_write_results of the component Netfs. The manipulation of the argument subrequests/flags leads to Remote Privilege Escalation. This vulnerability is uniquely identified as CVE-2026-64067. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 7.0.10. This issue affects the function netfs_collect_read_results/netfs_collect_write_results of the component Netfs. The manipulation of the argument subrequests/flags with an unknown input leads to a remote privilege escalation vulnerability. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: netfs: Fix missing barriers when accessing stream->subrequests locklessly The list of subrequests attached to stream->subrequests is accessed without locks by netfs_collect_read_results() and netfs_collect_write_results(), and then they access subreq->flags without taking a barrier after getting the subreq pointer from the list. Relatedly, the functions that build the list don't use any sort of write barrier when constructing the list to make sure that the NETFS_SREQ_IN_PROGRESS flag is perceived to be set first if no lock is taken. Fix this by: (1) Add a new list_add_tail_release() function that uses a release barrier to set the pointer to the new member of the list. (2) Add a new list_first_entry_or_null_acquire() function that uses an acquire barrier to read the pointer to the first member in a list (or return NULL). (3) Use list_add_tail_release() when adding a subreq to ->subrequests. (4) Use list_first_entry_or_null_acquire() when initially accessing the front of the list (when an item is removed, the pointer to the new front iterm is obtained under the same lock).

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-64067 since 07/19/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/19/2026).

Upgrading to version 7.0.11 eliminates this vulnerability.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.0.0
• 7.0.1
• 7.0.2
• 7.0.3
• 7.0.4
• 7.0.5
• 7.0.6
• 7.0.7
• 7.0.8
• 7.0.9
• 7.0.10

License

• open-source

Website

• Vendor: https://www.kernel.org/

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