diff options
| author | Eric Biggers <ebiggers@google.com> | 2020-11-17 23:56:07 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-12-26 16:02:44 +0100 |
| commit | c2c9944b5607357568f629f93a592db4540206fe (patch) | |
| tree | fd7c0b87d021e9950e2feae7b4354f05819a0877 | |
| parent | e5a2a002f83d0bf6b1972cf20c5359c50dda471c (diff) | |
f2fs: prevent creating duplicate encrypted filenames
commit bfc2b7e8518999003a61f91c1deb5e88ed77b07d upstream.
As described in "fscrypt: add fscrypt_is_nokey_name()", it's possible to
create a duplicate filename in an encrypted directory by creating a file
concurrently with adding the directory's encryption key.
Fix this bug on f2fs by rejecting no-key dentries in f2fs_add_link().
Note that the weird check for the current task in f2fs_do_add_link()
seems to make this bug difficult to reproduce on f2fs.
Fixes: 9ea97163c6da ("f2fs crypto: add filename encryption for f2fs_add_link")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201118075609.120337-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/f2fs/f2fs.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index cb700d797296..9a321c52face 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -3251,6 +3251,8 @@ bool f2fs_empty_dir(struct inode *dir); static inline int f2fs_add_link(struct dentry *dentry, struct inode *inode) { + if (fscrypt_is_nokey_name(dentry)) + return -ENOKEY; return f2fs_do_add_link(d_inode(dentry->d_parent), &dentry->d_name, inode, inode->i_ino, inode->i_mode); } |