lkml.org 
[lkml]   [2017]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.9 072/153] ext4: fix use-after-iput when fscrypt contexts are inconsistent
    Date
    4.9-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Eric Biggers <ebiggers@google.com>

    commit dd01b690f8f4b1e414f89e5a9a5326bf720d6652 upstream.

    In the case where the child's encryption context was inconsistent with
    its parent directory, we were using inode->i_sb and inode->i_ino after
    the inode had already been iput(). Fix this by doing the iput() in the
    correct places.

    Note: only ext4 had this bug, not f2fs and ubifs.

    Fixes: d9cdc9033181 ("ext4 crypto: enforce context consistency")
    Signed-off-by: Eric Biggers <ebiggers@google.com>
    Signed-off-by: Theodore Ts'o <tytso@mit.edu>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    fs/ext4/namei.c | 6 ++++--
    1 file changed, 4 insertions(+), 2 deletions(-)

    --- a/fs/ext4/namei.c
    +++ b/fs/ext4/namei.c
    @@ -1616,13 +1616,15 @@ static struct dentry *ext4_lookup(struct
    !fscrypt_has_permitted_context(dir, inode)) {
    int nokey = ext4_encrypted_inode(inode) &&
    !fscrypt_has_encryption_key(inode);
    - iput(inode);
    - if (nokey)
    + if (nokey) {
    + iput(inode);
    return ERR_PTR(-ENOKEY);
    + }
    ext4_warning(inode->i_sb,
    "Inconsistent encryption contexts: %lu/%lu",
    (unsigned long) dir->i_ino,
    (unsigned long) inode->i_ino);
    + iput(inode);
    return ERR_PTR(-EPERM);
    }
    }

    \
     
     \ /
      Last update: 2017-03-10 12:18    [W:4.111 / U:0.048 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site