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authorJ. Bruce Fields <bfields@redhat.com>2016-03-02 16:36:21 -0800
committerDmitry Shmidt <dimitrysh@google.com>2016-04-20 16:21:10 -0700
commit1298376aeaa89fbba976fae664e9e3cdb95e1fea (patch)
tree764e7eb7eff595b7bdc6082d7adae9dda622a41e
parente4a05bde6deacf39d6ec9305de587b0c2cec3ce0 (diff)
nfsd: fix deadlock secinfo+readdir compound
commit 2f6fc056e899bd0144a08da5cacaecbe8997cd74 upstream. nfsd_lookup_dentry exits with the parent filehandle locked. fh_put also unlocks if necessary (nfsd filehandle locking is probably too lenient), so it gets unlocked eventually, but if the following op in the compound needs to lock it again, we can deadlock. A fuzzer ran into this; normal clients don't send a secinfo followed by a readdir in the same compound. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/nfsd/nfs4proc.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index a9f096c7e99f..7d5351cd67fb 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -877,6 +877,7 @@ nfsd4_secinfo(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
&exp, &dentry);
if (err)
return err;
+ fh_unlock(&cstate->current_fh);
if (d_really_is_negative(dentry)) {
exp_put(exp);
err = nfserr_noent;