| Submitter | Shaohua Li |
|---|---|
| Date | June 9, 2011, 3:31 a.m. |
| Message ID | <1307590292.15392.71.camel@sli10-conroe> |
| Download | mbox | patch |
| Permalink | /patch/99611/ |
| State | Superseded |
| Headers | show |
Comments
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 Thanks! -Lukas > > Signed-off-by: Shaohua Li <shaohua.li@intel.com> > > 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; Again no data, no reason for backing off. > 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; This does not seem right, it there is no data we will end with ENOMEM for no reason. > /* 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@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
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(). > Thanks! > -Lukas > >> >> Signed-off-by: Shaohua Li <shaohua.li@intel.com> >> >> 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; > > Again no data, no reason for backing off. orig_data could be NULL if *data is NULL, or if kstrdup got ENOMEM. Anyway, please describe how the bug can arise, and then we can better evaluate the change. Thanks! -Eric >> 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; > > > This does not seem right, it there is no data we will end with ENOMEM > for no reason. > >> /* 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@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Patch
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;
orig_data could be NULL. Signed-off-by: Shaohua Li <shaohua.li@intel.com> -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html