NFS: Fix a possible Oops in fs/nfs/super.c

Sigh... commit 4584f520e1 (NFS: Fix NFS
mountpoint crossing...) had a slight flaw: server can be NULL if sget()
returned an existing superblock.

Fix the fix by dereferencing s->s_fs_info.

Thanks to Coverity/Adrian Bunk and Frank Filz for spotting the bug.
(See http://bugzilla.kernel.org/show_bug.cgi?id=9647)

Also add in the same namespace Oops fix for NFSv4 in both the mountpoint
crossing case, and the referral case.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2008-01-02 13:28:57 -05:00
parent b8c9a18712
commit e9cc6c234b

View file

@ -1475,7 +1475,7 @@ static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
error = PTR_ERR(mntroot);
goto error_splat_super;
}
if (mntroot->d_inode->i_op != server->nfs_client->rpc_ops->dir_inode_ops) {
if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
dput(mntroot);
error = -ESTALE;
goto error_splat_super;
@ -1826,6 +1826,11 @@ static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
error = PTR_ERR(mntroot);
goto error_splat_super;
}
if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
dput(mntroot);
error = -ESTALE;
goto error_splat_super;
}
s->s_flags |= MS_ACTIVE;
mnt->mnt_sb = s;
@ -1900,6 +1905,11 @@ static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
error = PTR_ERR(mntroot);
goto error_splat_super;
}
if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
dput(mntroot);
error = -ESTALE;
goto error_splat_super;
}
s->s_flags |= MS_ACTIVE;
mnt->mnt_sb = s;