summaryrefslogtreecommitdiffstats
path: root/fs/nfsd
diff options
context:
space:
mode:
authorJeff Layton <jlayton@poochiereds.net>2015-03-23 10:53:42 -0400
committerSasha Levin <sasha.levin@oracle.com>2015-04-23 14:58:26 -0400
commit5a472b11c0afd6457e4f4222083efa1536562496 (patch)
treee5d9b524284e988648382c7274f089d96ad2d6fc /fs/nfsd
parent76569d5333ee28b64ea5f772b24adecba952c047 (diff)
downloadlinux-stable-5a472b11c0afd6457e4f4222083efa1536562496.tar.gz
linux-stable-5a472b11c0afd6457e4f4222083efa1536562496.tar.bz2
linux-stable-5a472b11c0afd6457e4f4222083efa1536562496.zip
nfsd: return correct openowner when there is a race to put one in the hash
[ Upstream commit c5952338bfc234e54deda45b7228f610a545e28a ] alloc_init_open_stateowner can return an already freed entry if there is a race to put openowners in the hashtable. In commit 7ffb588086e9, we changed it so that we allocate and initialize an openowner, and then check to see if a matching one got stuffed into the hashtable in the meantime. If it did, then we free the one we just allocated and take a reference on the one already there. There is a bug here though. The code will then return the pointer to the one that was allocated (and has now been freed). This wasn't evident before as this race almost never occurred. The Linux kernel client used to serialize requests for a single openowner. That has changed now with v4.0 kernels, and this race can now easily occur. Fixes: 7ffb588086e9 Cc: <stable@vger.kernel.org> # v3.17+ Cc: Trond Myklebust <trond.myklebust@primarydata.com> Reported-by: Christoph Hellwig <hch@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'fs/nfsd')
-rw-r--r--fs/nfsd/nfs4state.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 5c9c13ee72f9..4296acd25f72 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3226,7 +3226,7 @@ alloc_init_open_stateowner(unsigned int strhashval, struct nfsd4_open *open,
} else
nfs4_free_openowner(&oo->oo_owner);
spin_unlock(&clp->cl_lock);
- return oo;
+ return ret;
}
static void init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp, struct nfsd4_open *open) {