pNFS/flexfiles: fix incorrect size check in decode_nfs_fh()
We (adam zabrocki, alexander matrosov, alexander tereshkin, maksym
bazalii) observed the check:
if (fh->size > sizeof(struct nfs_fh))
should not use the size of the nfs_fh struct which includes an extra two
bytes from the size field.
struct nfs_fh {
unsigned short size;
unsigned char data[NFS_MAXFHSIZE];
}
but should determine the size from data[NFS_MAXFHSIZE] so the memcpy
will not write 2 bytes beyond destination. The proposed fix is to
compare against the NFS_MAXFHSIZE directly, as is done elsewhere in fs
code base.
Fixes: d67ae825a59d ("pnfs/flexfiles: Add the FlexFile Layout Driver") Signed-off-by: Nikola Livic <nlivic@gmail.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>