From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E7C08286D5E for ; Mon, 13 Apr 2026 15:50:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776095431; cv=none; b=AZv6VnPv1jkR2Mso6KvQtIMxLxNy0OS8hb6aii06LA8DSiknHRCa2QB7xNL5L7ZuJB6Edzl7RQHQj6PROScLsQOwaxEBr6koIguDOb1G1i9EFbZGNg7eObvihSMdMqoZ9ygND9lS6t8ehluFeTrIC87KKThHzafyc1CeEB5cQiU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776095431; c=relaxed/simple; bh=X0hdRl494d49qU1E6wKPd7lLI0sbEvaZJC3jrT71Kok=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cxURvIPFutdn20mW3wjqbztlPKvCi38jt4rtVUG74xT1Wo47aFH5HdlJ5W0q01y2RW92zRFGyZ1P9S17xCXIvz0ubCRo9MYd8NjFwSv5foPFs4irvSY2vZfLVNkT1v/+3eEtsaVMfiwPfoRSs+7ta6nmWHdabJVMwr9KHBZVuNU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Uh6GsFZ9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Uh6GsFZ9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 86AEFC2BCB4; Mon, 13 Apr 2026 15:50:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776095430; bh=X0hdRl494d49qU1E6wKPd7lLI0sbEvaZJC3jrT71Kok=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Uh6GsFZ9fBILsefargGXzxjJFslllfGNwGKK9lyiyytRIfZTOB413gjZEdh6OD04+ Tyr7ahm4Wa+ASdrMGW7iValcQ9vF8QocvmKLQIP6M2B4nP4YBL+UgksGN2mViQRKeZ /kL/MUsq7V0bRxIlURuWwBQbZlPwaBsL1GHUgKJQpuCe4GCMRYYmsU94EvmAMdPtvB YveUGmXXwkPFDO3xw84TcAcVCdGXkY1DsBV+f6ieW1OzusTeBY2lfNKDSJzYa4idIQ obhX3YVMGF4pAtXvU2GzRwX3KhpQ2dIaO6H2vfN8R/rbBaIiYGMWToLz3qL5NsSoVI akUoFL1twUcVg== From: Sasha Levin To: stable@vger.kernel.org Cc: Joseph Qi , syzbot+62c1793956716ea8b28a@syzkaller.appspotmail.com, Mark Fasheh , Joel Becker , Junxiao Bi , Changwei Ge , Jun Piao , Heming Zhao , Andrew Morton , Sasha Levin Subject: [PATCH 5.15.y 3/3] ocfs2: fix out-of-bounds write in ocfs2_write_end_inline Date: Mon, 13 Apr 2026 11:50:25 -0400 Message-ID: <20260413155025.3145781-3-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260413155025.3145781-1-sashal@kernel.org> References: <2026041353-swimmer-skied-a346@gregkh> <20260413155025.3145781-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Joseph Qi [ Upstream commit 7bc5da4842bed3252d26e742213741a4d0ac1b14 ] KASAN reports a use-after-free write of 4086 bytes in ocfs2_write_end_inline, called from ocfs2_write_end_nolock during a copy_file_range splice fallback on a corrupted ocfs2 filesystem mounted on a loop device. The actual bug is an out-of-bounds write past the inode block buffer, not a true use-after-free. The write overflows into an adjacent freed page, which KASAN reports as UAF. The root cause is that ocfs2_try_to_write_inline_data trusts the on-disk id_count field to determine whether a write fits in inline data. On a corrupted filesystem, id_count can exceed the physical maximum inline data capacity, causing writes to overflow the inode block buffer. Call trace (crash path): vfs_copy_file_range (fs/read_write.c:1634) do_splice_direct splice_direct_to_actor iter_file_splice_write ocfs2_file_write_iter generic_perform_write ocfs2_write_end ocfs2_write_end_nolock (fs/ocfs2/aops.c:1949) ocfs2_write_end_inline (fs/ocfs2/aops.c:1915) memcpy_from_folio <-- KASAN: write OOB So add id_count upper bound check in ocfs2_validate_inode_block() to alongside the existing i_size check to fix it. Link: https://lkml.kernel.org/r/20260403063830.3662739-1-joseph.qi@linux.alibaba.com Signed-off-by: Joseph Qi Reported-by: syzbot+62c1793956716ea8b28a@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=62c1793956716ea8b28a Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Cc: Heming Zhao Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- fs/ocfs2/inode.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c index 0c11e298ec282..ead61176b0f28 100644 --- a/fs/ocfs2/inode.c +++ b/fs/ocfs2/inode.c @@ -1427,6 +1427,16 @@ int ocfs2_validate_inode_block(struct super_block *sb, goto bail; } + if (le16_to_cpu(data->id_count) > + ocfs2_max_inline_data_with_xattr(sb, di)) { + rc = ocfs2_error(sb, + "Invalid dinode #%llu: inline data id_count %u exceeds max %d\n", + (unsigned long long)bh->b_blocknr, + le16_to_cpu(data->id_count), + ocfs2_max_inline_data_with_xattr(sb, di)); + goto bail; + } + if (le64_to_cpu(di->i_size) > le16_to_cpu(data->id_count)) { rc = ocfs2_error(sb, "Invalid dinode #%llu: inline data i_size %llu exceeds id_count %u\n", -- 2.53.0