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=1794407861; b=hKuLKJYXuA/iJgKCC0u0v6iryUm+v5DoBK0ITUnbJ+MQdcmU7lmFPJz6n+ShD47Np0Fc CXxfKSR9jQtBBG4cWNXnDT6I0/Q4RUoN4vlrPm6KvU7jtUh/IhjjY0mIivZ3/9hfrzFlj JuAt+3ps+ePt9VwvDrUHQ426w2s9wqxzqnvRlle8Ov1P5zYpLfryKouVkTylU1pcxUFbD qSnQa5fG/q8rP7RBm6br8i2UMFBN9qxLKLztzppWc9hUtSczThPzUA/ZkHJyKIuC6w0JP 0jriWvqUZChOXtZAT886GHCjzH+FZAqx0GqqYa2MbAXMubO0LbOziLic8g9NT/q4GyA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794407861; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=fzBH9RldgGf92O9qexOtyFfwgspiOxTW6j94fkAplBk=; b=qzZ88ZVUBQCDcSSw6Rr1jmDq61KAzo+8N1aOROav+5DASWPtb8VFLPphEYHhJlUFC+yW P5nz9LNxlTTEvuUaXhm8qgVedhs3w94UFTujFNrk3xoc+uoIkLGivztNyk4v30N5DdvT5 NhRBIZILyTOprVkJU0HtWLr8yN52Sx4V138LJK8D44woS2TNmiFENRDHcOCuJp6Ozi2i7 GvGxkaulD7ULOxVDfUGj476MEkht+YZpgEDE+FiIoOyJRkBXYjTfxca6bAnSha8DO7Bge LPwkZUrYlydsmH9YX5UJC12IyX0w9/wLV7oiItOncRHgqJW8vE7x5HgwlWcSsMlwuoQ== 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=mkElcXIo; 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 D6148606A324 for ; Wed, 11 Nov 2026 14:37:41 +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=mkElcXIo Received: by smtp.kernel.org (Postfix) with ESMTPSA id 42EAC1F00A06; Wed, 11 Nov 2026 14:37:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794407861; bh=fzBH9RldgGf92O9qexOtyFfwgspiOxTW6j94fkAplBk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=mkElcXIoip7AS1T2QLc8ZU3L5C8AfQaQ+GKUGOpEmst0swfzSsYqy9N8/6AAU4ZiU VG7LwIE79voOdKaAtsU+c0OsUlf0QwwTk9eDBC+IE7ar1KX7P0zd32Z8edYDZ9m+rl dxc8ZWRVnhEwUn0hjYl24GgzQhtkAL7iJ72MQh38V3UHE2hhseVIpJ6dSfbrGXzTDS MJiINazk0Sop5xR6+NTmRkxzEHQq+HfxvshnnEiMukVRrvcByaVVq4IXPoaSlR/uGy AzwCg76SNFXHj12iA0+Pd04OWeO5PUSFUF3b6tlIzD3ASnBZ2T33ytID8gM+Yg0RiK Z9P+JK43fFhjw== From: Sasha Levin To: stable@vger.kernel.org Cc: Edward Adam Davis , syzbot+151afab124dfbc5f15e6@syzkaller.appspotmail.com, Heming Zhao , Joseph Qi , Mark Fasheh , Joel Becker , Junxiao Bi , Changwei Ge , Jun Piao , Andrew Morton , Sasha Levin Subject: [PATCH 5.15.y 1/2] ocfs2: fix oob in __ocfs2_find_path Date: Wed, 11 Nov 2026 09:37:37 -0500 Message-ID: <20261111143727.2371605-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261107060558-failed-5.15-6193ce7896af@kernel.org> References: <20261107060558-failed-5.15-6193ce7896af@kernel.org> 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-Transfer-Encoding: 8bit From: Edward Adam Davis [ Upstream commit e0b0f2834c9bec51b1068de5cf5e10c7519143eb ] syzbot constructed a corrupted image, which resulted in el->l_count from the b-tree extent block being 0. Since the length of the l_recs array depends on l_count, reading its member e_blkno triggered the out-of-bounds access reported by syzbot in [1]. The loop terminates when l_count is 0, similar to when next_free is 0. [1] UBSAN: array-index-out-of-bounds in fs/ocfs2/alloc.c:1838:11 index 0 is out of range for type 'struct ocfs2_extent_rec[] __counted_by(l_count)' (aka 'struct ocfs2_extent_rec[]') Call Trace: __ocfs2_find_path+0x606/0xa40 fs/ocfs2/alloc.c:1838 ocfs2_find_leaf+0xab/0x1c0 fs/ocfs2/alloc.c:1946 ocfs2_get_clusters_nocache+0x172/0xc60 fs/ocfs2/extent_map.c:418 ocfs2_get_clusters+0x505/0xa70 fs/ocfs2/extent_map.c:631 ocfs2_extent_map_get_blocks+0x202/0x6a0 fs/ocfs2/extent_map.c:678 ocfs2_read_virt_blocks+0x286/0x930 fs/ocfs2/extent_map.c:1001 ocfs2_read_dir_block fs/ocfs2/dir.c:521 [inline] ocfs2_find_entry_el fs/ocfs2/dir.c:728 [inline] ocfs2_find_entry+0x3e4/0x2090 fs/ocfs2/dir.c:1120 ocfs2_find_files_on_disk+0xdf/0x310 fs/ocfs2/dir.c:2023 ocfs2_lookup_ino_from_name+0x52/0x100 fs/ocfs2/dir.c:2045 _ocfs2_get_system_file_inode fs/ocfs2/sysfile.c:136 [inline] ocfs2_get_system_file_inode+0x326/0x770 fs/ocfs2/sysfile.c:112 ocfs2_init_global_system_inodes+0x319/0x660 fs/ocfs2/super.c:461 ocfs2_initialize_super fs/ocfs2/super.c:2196 [inline] ocfs2_fill_super+0x4432/0x65b0 fs/ocfs2/super.c:993 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 vfs_get_tree+0x92/0x2a0 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] Link: https://lkml.kernel.org/r/tencent_4D99464FA28D9225BE0DBA923F5DF6DD8C07@qq.com Signed-off-by: Edward Adam Davis Reported-by: syzbot+151afab124dfbc5f15e6@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=151afab124dfbc5f15e6 Reviewed-by: Heming Zhao Acked-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Signed-off-by: Andrew Morton Stable-dep-of: 6193ce7896af ("ocfs2: fix array out of bound access in __ocfs2_find_path()") Signed-off-by: Sasha Levin --- fs/ocfs2/alloc.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c index 9132e8594db32..cc0f4d4cb347d 100644 --- a/fs/ocfs2/alloc.c +++ b/fs/ocfs2/alloc.c @@ -1804,14 +1804,15 @@ static int __ocfs2_find_path(struct ocfs2_caching_info *ci, ret = -EROFS; goto out; } - if (le16_to_cpu(el->l_next_free_rec) == 0) { + if (!el->l_next_free_rec || !el->l_count) { ocfs2_error(ocfs2_metadata_cache_get_super(ci), - "Owner %llu has empty extent list at depth %u\n", + "Owner %llu has empty extent list at depth %u\n" + "(next free=%u count=%u)\n", (unsigned long long)ocfs2_metadata_cache_owner(ci), - le16_to_cpu(el->l_tree_depth)); + le16_to_cpu(el->l_tree_depth), + le16_to_cpu(el->l_next_free_rec), le16_to_cpu(el->l_count)); ret = -EROFS; goto out; - } for(i = 0; i < le16_to_cpu(el->l_next_free_rec) - 1; i++) { -- 2.53.0