Re: [PATCH?] reiserfs: prevent panic: don't allow %-char in journal dev. name
From: Jeff Mahoney
Date: Wed Apr 04 2018 - 21:49:05 EST
On 4/4/18 9:45 PM, Andrew Morton wrote:
> On Wed, 4 Apr 2018 18:25:16 -0700 Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote:
>
>> From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
>>
>> If the reiserfs mount option's journal name contains a '%' character,
>> it can lead to a WARN_ONCE() in lib/vsprintf.c::format_decode(),
>> saying: "Please remove unsupported %/ in format string."
>> That's OK until panic_on_warn is set, at which point it's dead, Jim.
>>
>> To placate this situation, check the journal name string for a '%'
>> character and return an error if one is found. Also print a warning
>> (one that won't panic the kernel) about the invalid journal name (e.g.):
>>
>> reiserfs: journal device name is invalid: %/file0
>>
>> (In this example, the caller app specified the journal device name as
>> "%/file0".)
>>
>
> Well, that is a valid filename and we should support it...
>
> Isn't the bug in journal_init_dev()?
Yep. That's exactly it.
Acked-by: Jeff Mahoney <jeffm@xxxxxxxx>
Thanks,
-Jeff
> --- a/fs/reiserfs/journal.c~a
> +++ a/fs/reiserfs/journal.c
> @@ -2643,7 +2643,7 @@ static int journal_init_dev(struct super
> if (IS_ERR(journal->j_dev_bd)) {
> result = PTR_ERR(journal->j_dev_bd);
> journal->j_dev_bd = NULL;
> - reiserfs_warning(super,
> + reiserfs_warning(super, "sh-457",
> "journal_init_dev: Cannot open '%s': %i",
> jdev_name, result);
> return result;
> _
>
>
--
Jeff Mahoney
SUSE Labs