From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7C226455176 for ; Fri, 11 Sep 2026 20:04:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789157071; cv=none; b=XgiOzu5CUZaJ9bE+5Aox6dSfjeckQ6uqEflA1j43PhIBGoKeE9MScIeIL37JkBXTx1ScIxpGAphhpsQ+sGWsvliCK13Dv2vxMcrMLKPS3l92gInBYtc/jqpv2ffIq5W+gig2ad8UagvyhL4+PC2QnD5tGlSUhYmuoqiD8d97NcI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789157071; c=relaxed/simple; bh=FLwcFyQ6GeVem95NLMuxeGm0VAFlc/M3s0ho2L1N+Yw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=J2F3Hk5p3Qwe4TKdHI+z8mhAFd+oitFzGmi2uhQ60xp1QEh5i7ZY+Mt7zwzGpMnLe/a564Jw3O02TdELIimzVQANVSHWhQmZXa9THd02fE4G4NkMMxEacZSK5/r2FLfmkiSlU4KV6zRfcS0KRxIgjBch6k5B6l+XpPsR/03EREk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=UzqG0DZE; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="UzqG0DZE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 149AA1F00893; Fri, 11 Sep 2026 20:04:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789157060; bh=ycl9cOs7CtVzBDEy+LnJVokPNY8/jXXbVBwFou0t+Qs=; h=From:To:Cc:Subject:Date:Reply-To; b=UzqG0DZEaRVeK2c3fI5vaGiRKfba+pvd4T7gMM4tugVwVX3aARXufLAkrB2S30ZX8 s48W4gfI+wOq8l1wAiVf9lTgBljFjb+gIpL8Xy7QiLBmnsziivRVDw13JcFFwXLpwq DrE7BSWkSSXgUOK2u7jRLi/XFl1IF2WHhnwNfMXk= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89723: nilfs2: fix slab-out-of-bounds in nilfs_direct_propagate after truncation Date: Fri, 11 Sep 2026 21:46:52 +0200 Message-ID: <2026091100-CVE-2026-89723-c489@gregkh> X-Mailer: git-send-email 2.55.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3704; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=Tm3VzqFblQ0XCI4dQ9c9jyR2kNpOk42838aaeaqjrt4=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIjvedIsrrLp7aqLo27lxK04K7bDSaGlp4vSxCOU38 v/246NlRywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAEzkoQPDfDc7UaXE9r1HRXKY X02PCZ/Lw6BdzTBPMa3a3sPNNelv1k/ZeaeC539/tJQPAA== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix slab-out-of-bounds in nilfs_direct_propagate after truncation Shuangpeng Bai reported that KASAN detected a slab-out-of-bounds error in nilfs_direct_propagate() during testing. Analysis revealed that after truncating a file, a node block immediately below the B-tree root was not deleted. Instead, it remained in the B-tree node cache in a dirty state. The log writer subsequently detected this block and incorrectly invoked nilfs_direct_propagate() on it, which is designed to handle only data blocks in direct mapping. B-tree nodes in the cache are managed by virtual block numbers, and their logical keys typically exceed the range expected by direct mapping. Consequently, processing such a node as a direct mapping entry triggers a slab-out-of-bounds access. The root cause is that when a B-tree mapping collapses into a direct mapping during truncation, an intermediate node block pointed to by the root node is left behind as garbage instead of being explicitly deleted. This resolves the issue by adding a nilfs_btree_discard() operation to delete the remaining intermediate node block during the conversion. A 'deform' flag is added to the bop_delete interface to explicitly signal that the deletion is part of a mapping transformation. This allows the B-tree mapping implementation to perform the necessary cleanup and discarding of the residual node structure that would be otherwise be left orphaned after the transition. The Linux kernel CVE team has assigned CVE-2026-89723 to this issue. Affected and fixed versions =========================== Issue introduced in 2.6.30 with commit 36a580eb489f54d81a0534974962e732a314b999 and fixed in 6.12.109 with commit 5d3783c451a546373662ee11ec17019273e68034 Issue introduced in 2.6.30 with commit 36a580eb489f54d81a0534974962e732a314b999 and fixed in 6.18.50 with commit 448636c745a3f3b8582a0b8ce718c890a11c0fa9 Issue introduced in 2.6.30 with commit 36a580eb489f54d81a0534974962e732a314b999 and fixed in 7.2.4 with commit 28362e8ce51377afdec1782e661e808328a10514 Issue introduced in 2.6.30 with commit 36a580eb489f54d81a0534974962e732a314b999 and fixed in 7.3-rc1 with commit 45662dedb8f272ef7f16e69f13424c4bd0399240 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-2026-89723 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/nilfs2/bmap.c fs/nilfs2/bmap.h fs/nilfs2/btree.c fs/nilfs2/direct.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/5d3783c451a546373662ee11ec17019273e68034 https://git.kernel.org/stable/c/448636c745a3f3b8582a0b8ce718c890a11c0fa9 https://git.kernel.org/stable/c/28362e8ce51377afdec1782e661e808328a10514 https://git.kernel.org/stable/c/45662dedb8f272ef7f16e69f13424c4bd0399240