From: Nikola Livic nlivic@gmail.com
[ Upstream commit ed34695e15aba74f45247f1ee2cf7e09d449f925 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfs/flexfilelayout/flexfilelayout.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c index 17771e157e92..e7f8732895b7 100644 --- a/fs/nfs/flexfilelayout/flexfilelayout.c +++ b/fs/nfs/flexfilelayout/flexfilelayout.c @@ -86,7 +86,7 @@ static int decode_nfs_fh(struct xdr_stream *xdr, struct nfs_fh *fh) if (unlikely(!p)) return -ENOBUFS; fh->size = be32_to_cpup(p++); - if (fh->size > sizeof(struct nfs_fh)) { + if (fh->size > NFS_MAXFHSIZE) { printk(KERN_ERR "NFS flexfiles: Too big fh received %d\n", fh->size); return -EOVERFLOW;