From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-68450: btrfs: free mapping node on duplicate reloc root insert
Date: Wed, 12 Aug 2026 09:50:26 +0900 [thread overview]
Message-ID: <2026081225-CVE-2026-68450-e589@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
btrfs: free mapping node on duplicate reloc root insert
__add_reloc_root() allocates a mapping_node before inserting it into
rc->reloc_root_tree. If rb_simple_insert() finds an existing entry, it
returns the existing rb_node and leaves the newly allocated node unlinked.
The error path then returns -EEXIST without freeing the new node. Since
the node was never inserted into reloc_root_tree, the later cleanup in
put_reloc_control() cannot find it either.
Free the newly allocated node before returning -EEXIST.
The callers currently assert that -EEXIST should not happen, so this is a
defensive cleanup for an unexpected duplicate insert path. If the path is
ever reached, the local allocation should still be released.
The Linux kernel CVE team has assigned CVE-2026-68450 to this issue.
Affected and fixed versions
===========================
Issue introduced in 5.13 with commit 57a304cfd43b2b4a5b44b8f5dc026abb34183068 and fixed in 6.6.148 with commit 92bedc0455552b42ada1a1f42b0e3a8593cdfccc
Issue introduced in 5.13 with commit 57a304cfd43b2b4a5b44b8f5dc026abb34183068 and fixed in 6.12.101 with commit 14a8be9428435ee17f17fae7991215c246b7fd43
Issue introduced in 5.13 with commit 57a304cfd43b2b4a5b44b8f5dc026abb34183068 and fixed in 6.18.42 with commit 797dc567146c7e3c4f8d9680e4fbc76e0a6d9151
Issue introduced in 5.13 with commit 57a304cfd43b2b4a5b44b8f5dc026abb34183068 and fixed in 7.1.6 with commit ae0629ff9ccb836416ada129f4edc7efea6eaaad
Issue introduced in 5.13 with commit 57a304cfd43b2b4a5b44b8f5dc026abb34183068 and fixed in 7.2-rc5 with commit 6a8269b6459ed870a8156c106a0f597383907872
Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.
Unaffected versions might change over time as fixes are backported to
older supported kernel versions. The official CVE entry at
https://cve.org/CVERecord/?id=CVE-2026-68450
will be updated if fixes are backported, please check that for the most
up to date information about this issue.
Affected files
==============
The file(s) affected by this issue are:
fs/btrfs/relocation.c
Mitigation
==========
The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes. Individual
changes are never tested alone, but rather are part of a larger kernel
release. Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all. If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
https://git.kernel.org/stable/c/92bedc0455552b42ada1a1f42b0e3a8593cdfccc
https://git.kernel.org/stable/c/14a8be9428435ee17f17fae7991215c246b7fd43
https://git.kernel.org/stable/c/797dc567146c7e3c4f8d9680e4fbc76e0a6d9151
https://git.kernel.org/stable/c/ae0629ff9ccb836416ada129f4edc7efea6eaaad
https://git.kernel.org/stable/c/6a8269b6459ed870a8156c106a0f597383907872
reply other threads:[~2026-08-12 0:52 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2026081225-CVE-2026-68450-e589@gregkh \
--to=gregkh@linuxfoundation.org \
--cc=cve@kernel.org \
--cc=gregkh@kernel.org \
--cc=linux-cve-announce@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.