From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-118.freemail.mail.aliyun.com (out30-118.freemail.mail.aliyun.com [115.124.30.118]) (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 1B6AD3DDDB1 for ; Tue, 1 Sep 2026 12:52:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.118 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788267156; cv=none; b=a5LIgqIRHILt+6VtvZm1F1KvwQp8mTN081KPXZCob0OjjScERQD/DJUGKDGNVexJ/W+ZKwYMz2f8cri4CcURAOxkDz7iJnLWjLrCmcn2GlnDvPywshl+5PfrO7LnInxsjAei9sOxx89eKHhspsnQJYGkzeFjPtrbpwU2u3xImNg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788267156; c=relaxed/simple; bh=VwqZK90dxuLVjGg6rgDcQEloreeN/ku+546Mw+4DdCI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=b0V1vxDOeBg/0NrckGpkYPn6s63Dh6POimM3Oxq4zfrnICrUTB6I8L4kRR3ksSZyzHHm7i+EMwQnig6WVcYAnmusRS18c6oMEQTIfemVXODM6fwmsusaIQNrDmaC8ULcuPHxQsU4J2AlcJCAwIq/rkUYoqP7PjB8vStaGCNWvo8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=rCR2Fphx; arc=none smtp.client-ip=115.124.30.118 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="rCR2Fphx" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1788267146; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=lO05Xg2Ij7GojObgHIN9IulfmzcQf0TBixu99pXyXZ0=; b=rCR2FphxkqQRYdRP8SptrDv/R4sf5SDClFpBQZvSVetbHOHAR70m3PespsDXZVdGepYHsSqJohRPFK+QHXxpJnb69Bn9JK+CMiICG/M5jaTZDFqT0aQNWpTu5JliL8q4qk3/ZdkuRCVC3C8InF0sreOtAW6/QB2GlW0WtUFAkcQ= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R391e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033037009110;MF=joseph.qi@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0XA8SdjK_1788267145; Received: from localhost(mailfrom:joseph.qi@linux.alibaba.com fp:SMTPD_---0XA8SdjK_1788267145 cluster:ay36) by smtp.aliyun-inc.com; Tue, 01 Sep 2026 20:52:25 +0800 From: Joseph Qi To: Andrew Morton , Heming Zhao Cc: Mark Fasheh , Joel Becker , ocfs2-devel@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v3 4/4] ocfs2: validate suballoc slot and bit of extent and refcount blocks Date: Tue, 1 Sep 2026 20:52:21 +0800 Message-Id: <20260901125221.1634686-5-joseph.qi@linux.alibaba.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20260901125221.1634686-1-joseph.qi@linux.alibaba.com> References: <20260901125221.1634686-1-joseph.qi@linux.alibaba.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit ocfs2_validate_extent_block() and ocfs2_validate_refcount_block() do not validate h_suballoc_slot, h_suballoc_bit, rf_suballoc_slot and rf_suballoc_bit at all. Since extent blocks and refcount blocks are allocated from a per-slot suballocator at runtime, their suballoc slots must be within range and their suballoc bits must fit in a block group bitmap. Otherwise a corrupted image can carry an out-of-range slot. When the extent block is freed, ocfs2_cache_extent_block_free() caches it and ocfs2_free_cached_blocks() later passes the unvalidated slot to ocfs2_get_system_file_inode(); when the refcount block is freed, ocfs2_remove_refcount_extent() passes it via ocfs2_cache_block_dealloc(). get_local_system_inode() will then either hit BUG_ON(slot == OCFS2_INVALID_SLOT) or compute an out-of-bounds index into the local_system_inodes array. Similarly an oversized suballoc bit will error out the filesystem in _ocfs2_free_suballoc_bits(). Furthermore group descriptor validation only guarantees bg_bits within the physical bitmap size, so a corrupted image can still carry a suballoc bit beyond bg_bits, which would let ocfs2_block_group_clear_bits() clear bits beyond bg_bitmap. Convert the remaining BUG_ON against group->bg_bits in _ocfs2_free_suballoc_bits() to ocfs2_error() as well. Reject out-of-range suballoc slots and oversized suballoc bits during validation. Signed-off-by: Joseph Qi --- fs/ocfs2/alloc.c | 27 +++++++++++++++++++++++++++ fs/ocfs2/refcounttree.c | 27 +++++++++++++++++++++++++++ fs/ocfs2/suballoc.c | 15 ++++++++++++++- 3 files changed, 68 insertions(+), 1 deletion(-) diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c index be09e766ac1f..2fdc5403b10b 100644 --- a/fs/ocfs2/alloc.c +++ b/fs/ocfs2/alloc.c @@ -925,6 +925,33 @@ static int ocfs2_validate_extent_block(struct super_block *sb, goto bail; } + /* + * Extent blocks are allocated from a per-slot suballocator, so the + * slot must be in range. Otherwise freeing the block passes it to + * get_local_system_inode(), which hits BUG_ON() for + * OCFS2_INVALID_SLOT or computes an out-of-bounds index otherwise. + */ + if ((u32)le16_to_cpu(eb->h_suballoc_slot) >= OCFS2_SB(sb)->max_slots) { + rc = ocfs2_error(sb, + "Extent block #%llu has an invalid h_suballoc_slot of %u\n", + (unsigned long long)bh->b_blocknr, + le16_to_cpu(eb->h_suballoc_slot)); + goto bail; + } + + /* + * Similarly the suballoc bit must fit in a block group bitmap. + * Otherwise freeing the block will pass the oversized bit to + * _ocfs2_free_suballoc_bits() and trigger ocfs2_error() there. + */ + if (le16_to_cpu(eb->h_suballoc_bit) >= ocfs2_suballoc_bits_per_block(sb)) { + rc = ocfs2_error(sb, + "Extent block #%llu has an invalid h_suballoc_bit of %u\n", + (unsigned long long)bh->b_blocknr, + le16_to_cpu(eb->h_suballoc_bit)); + goto bail; + } + if (le16_to_cpu(eb->h_list.l_count) != ocfs2_extent_recs_per_eb(sb)) { rc = ocfs2_error(sb, "Extent block #%llu has invalid l_count %u (expected %u)\n", diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c index d9f22b4a2654..3e9cccf06e48 100644 --- a/fs/ocfs2/refcounttree.c +++ b/fs/ocfs2/refcounttree.c @@ -117,6 +117,33 @@ static int ocfs2_validate_refcount_block(struct super_block *sb, goto out; } + /* + * Refcount blocks are allocated from a per-slot suballocator, so the + * slot must be in range. Otherwise freeing the block passes it to + * get_local_system_inode(), which hits BUG_ON() for + * OCFS2_INVALID_SLOT or computes an out-of-bounds index otherwise. + */ + if ((u32)le16_to_cpu(rb->rf_suballoc_slot) >= OCFS2_SB(sb)->max_slots) { + rc = ocfs2_error(sb, + "Refcount block #%llu has an invalid rf_suballoc_slot of %u\n", + (unsigned long long)bh->b_blocknr, + le16_to_cpu(rb->rf_suballoc_slot)); + goto out; + } + + /* + * Similarly the suballoc bit must fit in a block group bitmap. + * Otherwise freeing the block will pass the oversized bit to + * _ocfs2_free_suballoc_bits() and trigger ocfs2_error() there. + */ + if (le16_to_cpu(rb->rf_suballoc_bit) >= ocfs2_suballoc_bits_per_block(sb)) { + rc = ocfs2_error(sb, + "Refcount block #%llu has an invalid rf_suballoc_bit of %u\n", + (unsigned long long)bh->b_blocknr, + le16_to_cpu(rb->rf_suballoc_bit)); + goto out; + } + /* * rf_records (rl_count/rl_used/rl_recs[]) is only meaningful when * this block is not an interior tree block (OCFS2_REFCOUNT_TREE_FL); diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c index ce22d0c3d287..624152e4f7fe 100644 --- a/fs/ocfs2/suballoc.c +++ b/fs/ocfs2/suballoc.c @@ -3070,7 +3070,20 @@ static int _ocfs2_free_suballoc_bits(handle_t *handle, } group = (struct ocfs2_group_desc *) group_bh->b_data; - BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits)); + /* + * Group descriptor validation only guarantees bg_bits within the + * physical bitmap size, so double check the freeing range here. + * Otherwise ocfs2_block_group_clear_bits() would clear bits beyond + * bg_bitmap. + */ + if ((count + start_bit) > le16_to_cpu(group->bg_bits)) { + status = ocfs2_error(alloc_inode->i_sb, + "Group descriptor #%llu has %u bits, cannot free bits %u+%u\n", + (unsigned long long)le64_to_cpu(group->bg_blkno), + le16_to_cpu(group->bg_bits), + count, start_bit); + goto bail; + } if (ocfs2_is_cluster_bitmap(alloc_inode)) old_bg_contig_free_bits = group->bg_contig_free_bits; -- 2.39.3