Eric Biggers <ebiggers@xxxxxxxxxx> writes:
> From: Eric Biggers <ebiggers@xxxxxxxxxx>
>
> Tryng to rename a directory that has all following properties fails with
> EINVAL and triggers the 'WARN_ON_ONCE(!fscrypt_has_encryption_key(dir))'
> in f2fs_match_ci_name():
>
> - The directory is casefolded
> - The directory is encrypted
> - The directory's encryption key is not yet set up
> - The parent directory is *not* encrypted
>
> The problem is incorrect handling of the lookup of ".." to get the
> parent reference to update. fscrypt_setup_filename() treats ".." (and
> ".") specially, as it's never encrypted. It's passed through as-is, and
> setting up the directory's key is not attempted. As the name isn't a
> no-key name, f2fs treats it as a "normal" name and attempts a casefolded
> comparison. That breaks the assumption of the WARN_ON_ONCE() in
> f2fs_match_ci_name() which assumes that for encrypted directories,
> casefolded comparisons only happen when the directory's key is set up.
>
> We could just remove this WARN_ON_ONCE(). However, since casefolding is
> always a no-op on "." and ".." anyway, let's instead just not casefold
> these names. This results in the standard bytewise comparison.
>
> Fixes: 7ad08a58bf67 ("f2fs: Handle casefolding with Encryption")
> Cc: <stable@xxxxxxxxxxxxxxx> # v5.11+
> Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
> ---
> fs/f2fs/dir.c | 3 ++-
> fs/f2fs/f2fs.h | 10 +++++-----
> fs/f2fs/hash.c | 11 ++++++-----
> 3 files changed, 13 insertions(+), 11 deletions(-)
Hi Eric,
This looks good to me:
Reviewed-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
Thanks,
--
Gabriel Krisman Bertazi
