From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794048320; b=xDsrqsLHCwDU+j6nX9C/WykDgXd5qqePnHABPgjBR5xWS/ZFVSR7WweOQY+Lf4GwNspb //K42tB6uwLwON9SnqAwwChbOqTYU+SSXpOs1k1lRmxPspIp3IffUNTy+unzlNGNuu+Om PIWpqOGOET+Emya+6okciNQj2dVFXYoFkEkPNHg3ZSDU1EGwYowJlY8FWTMU5FSopzzB2 5vwr+e2pcTx+pUoJ2vU2x8FDtlngT8uE0CDxBMtiCHh4mmmasggG7dMnwdu32W07WFhOa xryQtJoyjtlQOPBl+SGbW4Cl05ZjJzii9qOOjQOlGJJjBxJlaUD6lRM0jasUW7SLxuA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794048320; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=tBGEtT3l+B1Kqq1OhSCxBEkxSRIPPQYCwinfZnoQmXM=; b=FCDOme3rpxKwUetWCssgDtiOc9rZ6ZDFb2d+BwfoP+WES06eqo2g+OplI3KTMrG4j/AJ 47zuGN2n3LaPrwr1gnpnIlsmneyvTFrPtmX5Nd9MSphxTp5hwMU6fU6eGFAP6jXwsvuLf N/Lbv8iyeclRj5StniEhtMijoP0dOuef49wTnsPOLugpUVuAJ5ELi28V6zSDElAyI7TIC Z0svK7oHBjnWZ6V0FHB2N4f8cns8jmASXPFxLupyHCyGoz4zpBSfhu9zDWXiwVyE0PwCi TECTH5j5jHMEY4xJoGqY8GzF+y3U9eItuSibczhLQChCkwaswWMA3wgcFIkV7Kv6Zww== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=R9QAaa0q; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6C459606A32C for ; Sat, 7 Nov 2026 10:45:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=R9QAaa0q Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5DBC61F0089F; Sat, 7 Nov 2026 10:45:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794048320; bh=tBGEtT3l+B1Kqq1OhSCxBEkxSRIPPQYCwinfZnoQmXM=; h=From:To:Cc:Subject:Date; b=R9QAaa0qYuyTCbVF1dyoy8pSQnYrtQ2uWHqsjrwBJgLc3Nie8OVYG7b+zzZUsG7v4 TKHYVhl7TTjLsW8t6gAvXBNzsT9oO12UJDN+8ivfOzGuYCA8qW68CtrPlsrY6jXYF8 1b43VdYcm2deTOXGx4Rg65UMw3PC7yZgyThl1WjPr4/yGmhjXDwfkUt704AnpEN+cV cVWBKx3/JtS8vmjDkWL12oNtFMxfe8AZl+Mqf6sNQdhCtWk2XXszuM7MQdUUkqb7+P zyMOuoGUhlIJuE2W55slZCQ+OL4jL5KoxA6AuCXh4s2iPgk27BjFqLa5kTydjyyWUZ no9B3n5+h6QzQ== From: Sasha Levin To: joseph.qi@linux.alibaba.com, akpm@linux-foundation.org, gechangwei@live.cn, heming.zhao@suse.com, jlbec@evilplan.org, piaojun@huawei.com, junxiao.bi@oracle.com, mark@fasheh.com Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] ocfs2: restrict OCFS2_INVALID_SLOT suballoc slot to system inodes" failed to apply to 6.1-stable tree Date: Sat, 7 Nov 2026 05:45:17 -0500 Message-ID: <20261107054517-failed-6.1-25bf9e549360@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 25bf9e549360b656a6763232e0e9e58a00c3aff7 # git commit -s git send-email --to '' --in-reply-to '20261107054517-failed-6.1-25bf9e549360@kernel.org' --subject-prefix 'PATCH 6.1.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 25bf9e549360b656a6763232e0e9e58a00c3aff7 Mon Sep 17 00:00:00 2001 From: Joseph Qi Date: Tue, 1 Sep 2026 20:52:18 +0800 Subject: [PATCH] ocfs2: restrict OCFS2_INVALID_SLOT suballoc slot to system inodes Patch series "ocfs2: validate suballoc slot and bit of metadata blocks", v3. The ocfs2 metadata validators trust the on-disk suballoc slot and bit without checking them against the slot range of the mounted filesystem and the capacity of the block group bitmap. A corrupted image can carry OCFS2_INVALID_SLOT or another out-of-range slot, or a suballoc bit beyond the bitmap, and once the corresponding inode, extent block, xattr block, dir index root or refcount block gets freed, the bad value goes straight into ocfs2_get_system_file_inode() or _ocfs2_free_suballoc_bits() and hits a BUG_ON() or runs off the end of local_system_inodes[]. This series rejects such values at read time, in the existing validators, so corrupted objects fail with -EROFS (and a read-only remount) instead of crashing: patch 1 restricts OCFS2_INVALID_SLOT dinodes to system inodes, completing fe7a283b3916 ("ocfs2: add suballoc slot check in ocfs2_validate_inode_block()"), and turns the "system file state is ambiguous" BUG_ON() in ocfs2_read_locked_inode() into an ocfs2_error(); patch 2 rejects oversized dinode suballoc bits; patch 3 validates the suballoc slot and bit of xattr and dir index blocks; patch 4 validates the suballoc slot and bit of extent and refcount blocks. The checks only enforce what the kernel and mkfs.ocfs2 already write: a valid slot from meta_ac->ac_alloc_slot and a bit within the block group bitmap, with system inodes carrying OCFS2_INVALID_SLOT plus OCFS2_SYSTEM_FL and extent blocks using slot 0. Nothing changes for healthy filesystems. Each new check was exercised under QEMU by corrupting the field in question with an out-of-range value; with the series applied the access fails with -EROFS and the filesystem remounts read-only instead of hitting the BUG_ON(). This patch (of 4): ocfs2_validate_inode_block() currently permits i_suballoc_slot to be OCFS2_INVALID_SLOT for any dinode. Only system inodes created by mkfs.ocfs2 are allocated from the global allocator and thus legitimately carry this value; regular inodes are always allocated from a per-slot suballocator and hence must have a valid slot. If a corrupted regular inode with OCFS2_INVALID_SLOT is accepted, ocfs2_remove_inode() will pass the slot to ocfs2_get_system_file_inode() and get_local_system_inode() will hit BUG_ON(slot == OCFS2_INVALID_SLOT) when the inode is deleted. This can be triggered by an unprivileged user unlinking such a corrupted file. Reject OCFS2_INVALID_SLOT for non-system dinodes during validation, while still accepting it for system inodes. Note that a crafted dinode carrying OCFS2_SYSTEM_FL passes the check above, yet a plain lookup of it still used to BUG() in ocfs2_read_locked_inode() ("system file state is ambiguous"). Since i_flags comes from disk, handle that mismatch with ocfs2_error() instead of BUG_ON() as well. Link: https://lore.kernel.org/20260901125221.1634686-1-joseph.qi@linux.alibaba.com Link: https://lore.kernel.org/20260901125221.1634686-2-joseph.qi@linux.alibaba.com Fixes: fe7a283b3916 ("ocfs2: add suballoc slot check in ocfs2_validate_inode_block()") Signed-off-by: Joseph Qi Signed-off-by: Andrew Morton Cc: Changwei Ge Cc: Heming Zhao Cc: Joel Becker Cc: Jun Piao Cc: Junxiao Bi Cc: Mark Fasheh Cc: --- fs/ocfs2/inode.c | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-) diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c index 180107a11046c..9228d6ef23c24 100644 --- a/fs/ocfs2/inode.c +++ b/fs/ocfs2/inode.c @@ -638,14 +638,18 @@ static int ocfs2_read_locked_inode(struct inode *inode, fe = (struct ocfs2_dinode *) bh->b_data; /* - * This is a code bug. Right now the caller needs to - * understand whether it is asking for a system file inode or - * not so the proper lock names can be built. + * The caller must know whether it is asking for a system file inode + * or not so the proper lock names can be built. Since i_flags comes + * from disk, a mismatch is filesystem corruption instead of a code + * bug, so handle it with ocfs2_error() rather than BUG_ON(). */ - mlog_bug_on_msg(!!(fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL)) != - !!(args->fi_flags & OCFS2_FI_FLAG_SYSFILE), - "Inode %llu: system file state is ambiguous\n", - (unsigned long long)args->fi_blkno); + if (!!(fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL)) != + !!(args->fi_flags & OCFS2_FI_FLAG_SYSFILE)) { + status = ocfs2_error(osb->sb, + "Inode %llu: system file state is ambiguous\n", + (unsigned long long)args->fi_blkno); + goto bail; + } if (S_ISCHR(le16_to_cpu(fe->i_mode)) || S_ISBLK(le16_to_cpu(fe->i_mode))) @@ -1520,8 +1524,23 @@ int ocfs2_validate_inode_block(struct super_block *sb, goto bail; } - if (le16_to_cpu(di->i_suballoc_slot) != (u16)OCFS2_INVALID_SLOT && - (u32)le16_to_cpu(di->i_suballoc_slot) > OCFS2_SB(sb)->max_slots - 1) { + /* + * Only system inodes created by mkfs.ocfs2 are allocated from the + * global allocator and thus legitimately carry OCFS2_INVALID_SLOT. + * Regular inodes are always allocated from a per-slot suballocator. + * If a regular inode with OCFS2_INVALID_SLOT was accepted here, + * deleting it would pass the slot to get_local_system_inode() via + * ocfs2_remove_inode() and trigger BUG_ON(slot == OCFS2_INVALID_SLOT). + */ + if (le16_to_cpu(di->i_suballoc_slot) == (u16)OCFS2_INVALID_SLOT) { + if (!(le32_to_cpu(di->i_flags) & OCFS2_SYSTEM_FL)) { + rc = ocfs2_error(sb, + "Invalid dinode %llu: suballoc slot %u for non-system inode\n", + (unsigned long long)bh->b_blocknr, + le16_to_cpu(di->i_suballoc_slot)); + goto bail; + } + } else if ((u32)le16_to_cpu(di->i_suballoc_slot) > OCFS2_SB(sb)->max_slots - 1) { rc = ocfs2_error(sb, "Invalid dinode %llu: suballoc slot %u\n", (unsigned long long)bh->b_blocknr, le16_to_cpu(di->i_suballoc_slot)); -- 2.53.0