Bug 2482642 (CVE-2026-46164)

Summary: CVE-2026-46164 kernel: btrfs: fix double free in create_space_info_sub_group() error path
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's btrfs filesystem. This vulnerability, a double free, occurs in the `create_space_info_sub_group()` function's error handling path. When `kobject_init_and_add()` fails, a memory region can be freed twice. This can lead to memory corruption, potentially resulting in a denial of service or other unpredictable system behavior.
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-05-28 11:07:17 UTC 
In the Linux kernel, the following vulnerability has been resolved:

btrfs: fix double free in create_space_info_sub_group() error path

When kobject_init_and_add() fails, the call chain is:

create_space_info_sub_group()
-> btrfs_sysfs_add_space_info_type()
-> kobject_init_and_add()
-> failure
-> kobject_put(&sub_group->kobj)
-> space_info_release()
-> kfree(sub_group)

Then control returns to create_space_info_sub_group(), where:

btrfs_sysfs_add_space_info_type() returns error
-> kfree(sub_group)

Thus, sub_group is freed twice.

Keep parent->sub_group[index] = NULL for the failure path, but after
btrfs_sysfs_add_space_info_type() has called kobject_put(), let the
kobject release callback handle the cleanup.
Comment 1 Keith Grant 2026-05-28 15:34:24 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026052825-CVE-2026-46164-6259@gregkh/T