Re: [PATCH?] reiserfs: prevent panic: don't allow %-char in journal dev. name

[Jan Kara]

On Mon 09-04-18 16:25:17, Jan Kara wrote:
> On Wed 04-04-18 21:48:53, Jeff Mahoney wrote:
> > 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. I've picked up the patch from Andrew, added his Signed-off-by (OK,
> Andrew?), wrote a proper changelog and pushed it to my tree. The result is
> attached.

Ah, now I've noticed Andrew pushed the patch to his tree. Removing mine and
sorry for the noise.

								Honza
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR