On Fri, 10 Jun 2011, Shaohua Li wrote: > On Thu, 2011-06-09 at 22:51 +0800, Eric Sandeen wrote: > > On 6/9/11 4:24 AM, Lukas Czerner wrote: > > > On Thu, 9 Jun 2011, Shaohua Li wrote: > > > > > >> orig_data could be NULL. > > > > > > Now, that is the commit description :). Could you please be more > > > descriptive in the "descritpion" ? Also the subject is not right either, > > > please see Documentation/SubmittingPatches > > > > Yes; if possible please use the commit message to describe how/why orig_data > > can be NULL; a testcase if one exists; the resulting flaw (null pointer deref?) > > etc. > > > > something like: > > > > Subject: [PATCH] ext4: check for NULL orig_data pointer in mount paths > > > > The orig_data pointer in ext4_fill_super() and ext4_remount() > > can be null if < ??? >, which can lead to < ??? > in the mount > > and remount paths. This can be demonstrated by < ??? >. > > To avoid this, we can simply test for the null pointer > > and return an error in ext4_fill_super() and ext4_remount(). > I thought the reason is pretty straightforward, anyway here is the > updated patch. > > Subject: [patch]ext4: check NULL pointer for mount and remount > > orig_data could be NULL, because the memory allocation of kstrdup() could fail. > Add the NULL check. I am sorry, but as I pointed out in previous mail this is not true. *orig_data can be also NULL in the case that *data is NULL and hence there is no reason for exiting with error. Also please use the subject Eric suggested. Thanks! -Lukas > > Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx> > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index cc5c157..45fc255 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -3057,6 +3057,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) > unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO; > ext4_group_t first_not_zeroed; > > + if (!orig_data) > + return ret; > sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); > if (!sbi) > goto out_free_orig; > @@ -4285,6 +4287,8 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) > #endif > char *orig_data = kstrdup(data, GFP_KERNEL); > > + if (!orig_data) > + return -ENOMEM; > /* Store the original options */ > lock_super(sb); > old_sb_flags = sb->s_flags; > > > -- -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
