linux-kernel - [PATCH 5.11 046/120] nfsd: Dont keep looking up unhashed files in the nfsd file cache

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 22 Mar 2021 13:27:09 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Trond Myklebust <trond.myklebust@...merspace.com>,
        Chuck Lever <chuck.lever@...cle.com>
Subject: [PATCH 5.11 046/120] nfsd: Dont keep looking up unhashed files in the nfsd file cache

From: Trond Myklebust <trond.myklebust@...merspace.com>

commit d30881f573e565ebb5dbb50b31ed6106b5c81328 upstream.

If a file is unhashed, then we're going to reject it anyway and retry,
so make sure we skip it when we're doing the RCU lockless lookup.
This avoids a number of unnecessary nfserr_jukebox returns from
nfsd_file_acquire()

Fixes: 65294c1f2c5e ("nfsd: add a new struct file caching facility to nfsd")
Signed-off-by: Trond Myklebust <trond.myklebust@...merspace.com>
Signed-off-by: Chuck Lever <chuck.lever@...cle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 fs/nfsd/filecache.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -898,6 +898,8 @@ nfsd_file_find_locked(struct inode *inod
 			continue;
 		if (!nfsd_match_cred(nf->nf_cred, current_cred()))
 			continue;
+		if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags))
+			continue;
 		if (nfsd_file_get(nf) != NULL)
 			return nf;
 	}