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authorJ. Bruce Fields <bfields@redhat.com>2016-03-02 16:36:21 -0800
committerJ. Bruce Fields <bfields@redhat.com>2016-03-16 10:51:21 -0400
commit2f6fc056e899bd0144a08da5cacaecbe8997cd74 (patch)
treed3fcc2454af13cf417413152c3c229e6b5d45676
parent0f1738a10bf03f6406b7b071c2a76b22e687d9c9 (diff)
nfsd: fix deadlock secinfo+readdir compound
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. Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
-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 410516e9867f..40b912407d51 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -876,6 +876,7 @@ 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;