summaryrefslogtreecommitdiffstats
path: root/fs/nfsd
diff options
context:
space:
mode:
authorJ. Bruce Fields <bfields@redhat.com>2020-08-05 15:10:11 -0400
committerChuck Lever <chuck.lever@oracle.com>2020-08-16 16:51:18 -0400
commit34b09af4f54e6485e28f138ccad159611a240cc1 (patch)
treecb6eb798908b79762eb4e775abd24ec1b6fc26cc /fs/nfsd
parent9123e3a74ec7b934a4a099e98af6a61c2f80bbf5 (diff)
downloadlinux-34b09af4f54e6485e28f138ccad159611a240cc1.tar.bz2
nfsd: fix oops on mixed NFSv4/NFSv3 client access
If an NFSv2/v3 client breaks an NFSv4 client's delegation, it will hit a NULL dereference in nfsd_breaker_owns_lease(). Easily reproduceable with for example mount -overs=4.2 server:/export /mnt/ sleep 1h </mnt/file & mount -overs=3 server:/export /mnt2/ touch /mnt2/file Reported-by: Robert Dinse <nanook@eskimo.com> Fixes: 28df3d1539de50 ("nfsd: clients don't need to break their own delegations") BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=208807 Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'fs/nfsd')
-rw-r--r--fs/nfsd/nfs4state.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 81ed8e8bab3f..1ea9bbcc7c24 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4597,6 +4597,8 @@ static bool nfsd_breaker_owns_lease(struct file_lock *fl)
if (!i_am_nfsd())
return NULL;
rqst = kthread_data(current);
+ if (!rqst->rq_lease_breaker)
+ return NULL;
clp = *(rqst->rq_lease_breaker);
return dl->dl_stid.sc_client == clp;
}