Bug 2482655 (CVE-2026-46129)

Summary: CVE-2026-46129 kernel: btrfs: fix double free in create_space_info() error path
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel, specifically within the btrfs filesystem. This vulnerability, a double free, occurs in the `create_space_info()` function's error handling path. When an internal object initialization fails, the system attempts to release memory twice for the same resource. This can lead to system instability or a denial of service (DoS), making the system unavailable to legitimate users.
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Description OSIDB Bzimport 2026-05-28 11:07:56 UTC 
In the Linux kernel, the following vulnerability has been resolved:

btrfs: fix double free in create_space_info() error path

When kobject_init_and_add() fails, the call chain is:

create_space_info()
-> btrfs_sysfs_add_space_info_type()
-> kobject_init_and_add()
-> failure
-> kobject_put(&space_info->kobj)
-> space_info_release()
-> kfree(space_info)

Then control returns to create_space_info():

btrfs_sysfs_add_space_info_type() returns error
-> goto out_free
-> kfree(space_info)

This causes a double free.

Keep the direct kfree(space_info) for the earlier 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 17:41:57 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026052817-CVE-2026-46129-5c77@gregkh/T