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Subject[PATCH v3 3/3] quota: Add more checking after reading from quota file
Date
It would be better to do more sanity checking (eg. dqdh_entries,
block no.) for the content read from quota file, which can prevent
corrupting the quota file.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
---
fs/quota/quota_tree.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c
index 0fa73ca28045..0f1493e0f6d0 100644
--- a/fs/quota/quota_tree.c
+++ b/fs/quota/quota_tree.c
@@ -96,6 +96,11 @@ static int check_dquot_block_header(struct qtree_mem_dqinfo *info,
err = do_check_range(info->dqi_sb, "dqdh_prev_free",
le32_to_cpu(dh->dqdh_prev_free), 0,
info->dqi_blocks - 1);
+ if (err)
+ return err;
+ err = do_check_range(info->dqi_sb, "dqdh_entries",
+ le16_to_cpu(dh->dqdh_entries), 0,
+ qtree_dqstr_in_blk(info));

return err;
}
@@ -348,6 +353,10 @@ static int do_insert_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
}
ref = (__le32 *)buf;
newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
+ ret = do_check_range(dquot->dq_sb, "block", newblk, 0,
+ info->dqi_blocks - 1);
+ if (ret)
+ goto out_buf;
if (!newblk)
newson = 1;
if (depth == info->dqi_qtree_depth - 1) {
@@ -739,15 +748,21 @@ static int find_next_id(struct qtree_mem_dqinfo *info, qid_t *id,
goto out_buf;
}
for (i = __get_index(info, *id, depth); i < epb; i++) {
- if (ref[i] == cpu_to_le32(0)) {
+ uint blk_no = le32_to_cpu(ref[i]);
+
+ if (blk_no == 0) {
*id += level_inc;
continue;
}
+ ret = do_check_range(info->dqi_sb, "block", blk_no, 0,
+ info->dqi_blocks - 1);
+ if (ret)
+ goto out_buf;
if (depth == info->dqi_qtree_depth - 1) {
ret = 0;
goto out_buf;
}
- ret = find_next_id(info, id, le32_to_cpu(ref[i]), depth + 1);
+ ret = find_next_id(info, id, blk_no, depth + 1);
if (ret != -ENOENT)
break;
}
--
2.31.1
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