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

From: Andrew Morton
Date: Wed Apr 04 2018 - 21:45:25 EST

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()?

--- 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;