NFSD: fix use-after-free in __nfs42_ssc_open()

commit 75333d48f92256a0dec91dbf07835e804fc411c0 upstream.

Problem caused by source's vfsmount being unmounted but remains
on the delayed unmount list. This happens when nfs42_ssc_open()
return errors.

Fixed by removing nfsd4_interssc_connect(), leave the vfsmount
for the laundromat to unmount when idle time expires.

We don't need to call nfs_do_sb_deactive when nfs42_ssc_open
return errors since the file was not opened so nfs_server->active
was not incremented. Same as in nfsd4_copy, if we fail to
launch nfsd4_do_async_copy thread then there's no need to
call nfs_do_sb_deactive

Reported-by: Xingyuan Mo <hdthky0@gmail.com>
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Tested-by: Xingyuan Mo <hdthky0@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dai Ngo 2022-12-12 14:50:11 -08:00 committed by Greg Kroah-Hartman
parent a9e53869cb
commit ec5b781435

View File

@ -1351,13 +1351,6 @@ out_err:
return status;
}
static void
nfsd4_interssc_disconnect(struct vfsmount *ss_mnt)
{
nfs_do_sb_deactive(ss_mnt->mnt_sb);
mntput(ss_mnt);
}
/*
* Verify COPY destination stateid.
*
@ -1460,11 +1453,6 @@ nfsd4_cleanup_inter_ssc(struct vfsmount *ss_mnt, struct nfsd_file *src,
{
}
static void
nfsd4_interssc_disconnect(struct vfsmount *ss_mnt)
{
}
static struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
struct nfs_fh *src_fh,
nfs4_stateid *stateid)
@ -1622,14 +1610,14 @@ static int nfsd4_do_async_copy(void *data)
copy->nf_src = kzalloc(sizeof(struct nfsd_file), GFP_KERNEL);
if (!copy->nf_src) {
copy->nfserr = nfserr_serverfault;
nfsd4_interssc_disconnect(copy->ss_mnt);
/* ss_mnt will be unmounted by the laundromat */
goto do_callback;
}
copy->nf_src->nf_file = nfs42_ssc_open(copy->ss_mnt, &copy->c_fh,
&copy->stateid);
if (IS_ERR(copy->nf_src->nf_file)) {
copy->nfserr = nfserr_offload_denied;
nfsd4_interssc_disconnect(copy->ss_mnt);
/* ss_mnt will be unmounted by the laundromat */
goto do_callback;
}
}
@ -1714,8 +1702,10 @@ out_err:
if (async_copy)
cleanup_async_copy(async_copy);
status = nfserrno(-ENOMEM);
if (!copy->cp_intra)
nfsd4_interssc_disconnect(copy->ss_mnt);
/*
* source's vfsmount of inter-copy will be unmounted
* by the laundromat
*/
goto out;
}