diff options
| author | Zhihao Cheng <chengzhihao1@huawei.com> | 2023-09-23 11:28:59 +0800 |
|---|---|---|
| committer | Richard Weinberger <richard@nod.at> | 2023-10-28 23:19:08 +0200 |
| commit | 75690493591fe283e4c92a3ba7c4420e9858abdb (patch) | |
| tree | 6a9e05748db7f109e8106e93b9d3bf2824398bf9 | |
| parent | d07cec9c238ae8fc6c1a9f3f5d30a2f8ec6cdc71 (diff) | |
| download | ubifs-75690493591fe283e4c92a3ba7c4420e9858abdb.tar.gz | |
ubifs: ubifs_link: Fix wrong name len calculating when UBIFS is encryptedHEADubifs-for-linus-6.7-rc1ubifs-for-linus-6.7-rcmaster
The length of dentry name is calculated after the raw name is encrypted,
except for ubifs_link(), which could make the size of dir underflow.
Here is a reproducer:
touch $TMP/file
mkdir $TMP/dir
stat $TMP/dir
for i in $(seq 1 8)
do
ln $TMP/file $TMP/dir/$i
unlink $TMP/dir/$i
done
stat $TMP/dir
The size of dir will be underflow(-96).
Fix it by calculating dentry name's length after the name is encrypted.
Fixes: f4f61d2cc6d8 ("ubifs: Implement encrypted filenames")
Reported-by: Roland Ruckerbauer <roland.ruckerbauer@robart.cc>
Link: https://lore.kernel.org/linux-mtd/1638777819.2925845.1695222544742.JavaMail.zimbra@robart.cc/T/#u
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
| -rw-r--r-- | fs/ubifs/dir.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 2f48c58d47cdd0..5dc1ac4d826def 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -724,7 +724,7 @@ static int ubifs_link(struct dentry *old_dentry, struct inode *dir, struct inode *inode = d_inode(old_dentry); struct ubifs_inode *ui = ubifs_inode(inode); struct ubifs_inode *dir_ui = ubifs_inode(dir); - int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len); + int err, sz_change; struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2, .dirtied_ino_d = ALIGN(ui->data_len, 8) }; struct fscrypt_name nm; @@ -748,6 +748,8 @@ static int ubifs_link(struct dentry *old_dentry, struct inode *dir, if (err) return err; + sz_change = CALC_DENT_SIZE(fname_len(&nm)); + err = dbg_check_synced_i_size(c, inode); if (err) goto out_fname; |