On Thu 16-05-19 09:16:06, cgxu519@xxxxxxxxxxx wrote:
> On Wed, 2019-05-15 at 16:01 +0200, Jan Kara wrote:
> > Check every entry in xattr block for validity in ext2_xattr_set() to
> > detect on disk corruption early. Also since e_value_block field in xattr
> > entry is never != 0 in a valid filesystem, just remove checks for it
> > once we have established entries are valid.
> >
> > Signed-off-by: Jan Kara <jack@xxxxxxx>
>
> Could we do the entry check in the loop of get/list operation too?
Yes, makes sense. Will add for v2. Thanks for review.
Honza
>
> Thanks,
> Chengguang
>
> > ---
> > fs/ext2/xattr.c | 15 ++++++---------
> > 1 file changed, 6 insertions(+), 9 deletions(-)
> >
> > diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
> > index 26a049ca89fb..04a4148d04b3 100644
> > --- a/fs/ext2/xattr.c
> > +++ b/fs/ext2/xattr.c
> > @@ -442,7 +442,9 @@ ext2_xattr_set(struct inode *inode, int name_index, const
> > char *name,
> > struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(last);
> > if ((char *)next >= end)
> > goto bad_block;
> > - if (!last->e_value_block && last->e_value_size) {
> > + if (!ext2_xattr_entry_valid(last, sb->s_blocksize))
> > + goto bad_block;
> > + if (last->e_value_size) {
> > size_t offs = le16_to_cpu(last->e_value_offs);
> > if (offs < min_offs)
> > min_offs = offs;
> > @@ -482,12 +484,7 @@ ext2_xattr_set(struct inode *inode, int name_index, const
> > char *name,
> > error = -EEXIST;
> > if (flags & XATTR_CREATE)
> > goto cleanup;
> > - if (!here->e_value_block && here->e_value_size) {
> > - if (!ext2_xattr_entry_valid(here, sb->s_blocksize))
> > - goto bad_block;
> > - free += EXT2_XATTR_SIZE(
> > - le32_to_cpu(here->e_value_size));
> > - }
> > + free += EXT2_XATTR_SIZE(le32_to_cpu(here->e_value_size));
> > free += EXT2_XATTR_LEN(name_len);
> > }
> > error = -ENOSPC;
> > @@ -552,7 +549,7 @@ ext2_xattr_set(struct inode *inode, int name_index, const
> > char *name,
> > here->e_name_len = name_len;
> > memcpy(here->e_name, name, name_len);
> > } else {
> > - if (!here->e_value_block && here->e_value_size) {
> > + if (here->e_value_size) {
> > char *first_val = (char *)header + min_offs;
> > size_t offs = le16_to_cpu(here->e_value_offs);
> > char *val = (char *)header + offs;
> > @@ -579,7 +576,7 @@ ext2_xattr_set(struct inode *inode, int name_index, const
> > char *name,
> > last = ENTRY(header+1);
> > while (!IS_LAST_ENTRY(last)) {
> > size_t o = le16_to_cpu(last->e_value_offs);
> > - if (!last->e_value_block && o < offs)
> > + if (o < offs)
> > last->e_value_offs =
> > cpu_to_le16(o + size);
> > last = EXT2_XATTR_NEXT(last);
>
>
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
