From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1817A3C10B2; Tue, 9 Jun 2026 17:48:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781027306; cv=none; b=ILxHJHts5+MAbxZLZxZwV+HrwyMPXVJ33HYnJ5eGolGNsAyHmPzYTidRqBq0EkbH58sm0EIby4hPdPxQCPyIQydxfgi5z4ScjBMdQR/0q1+q+JNggHz5BM22sEiaka2/8ghQx1PcJjeZdQAR7ansjO7SKnyG2PsefxGtMPEH6U4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781027306; c=relaxed/simple; bh=ElXBJxHoO/+5LnrW3BYnMZfLR1dfH4fwXtgt+PNtj7Q=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=fRx9WLIh+Sxfc2+aJ3QaHA4TQZ/zHp8LfHuq3W00bZN1LPMfw0OSjVnXAnP8CJmCpIHJ+j3yawz3d3/PebnauHVbOtH5QOPQm0ilyBe9iwNFSJ0CNpaXLkJvgBMn+cAFeM8qW7LXtDmGzVXgy0mARRY1o3Fonu/1WhCPoHNaSGI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ipNqYq0z; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ipNqYq0z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C69631F0089A; Tue, 9 Jun 2026 17:48:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781027304; bh=d9q6zLjIiqDu4jNpYSKwcJp0GtnMDCSLQqjcxNlh3Ho=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=ipNqYq0z+IBf7k7uIpftYQM0bnm/8M7Q9E8orYYg0eNoHo3a/9piT6wEa28b1/BDB XnoyWtwGU7cL/qUJ2/rNmsODT3J0BvVE5yDZM5t1yAdlftVKR6lMa2LeAQ29QT+P/C j4wFRo+jPoJxBqOvacsEtnqz++80828NUL5xicLlFWPPDIpWTsTtPkXGjdL4YBO6sy oC5+huh1IK7Bxn31gwBdAvSloC4JuhgFX/Lqo6FvglrVYGdUde4wetGoUKG5LYeLy4 2uEyligRN3KDrAWM8CYMbSa/nkymYuc79Vwf8sUE+CVWClaf6gIJ07XSGKdfsBSXKB 6X2WVAm70WjRA== From: Jeff Layton Date: Tue, 09 Jun 2026 13:47:40 -0400 Subject: [PATCH 19/19] nfsd: initialize DRC hash table before registering shrinker Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260609-nfsd-testing-v1-19-e83acead2ae8@kernel.org> References: <20260609-nfsd-testing-v1-0-e83acead2ae8@kernel.org> In-Reply-To: <20260609-nfsd-testing-v1-0-e83acead2ae8@kernel.org> To: Trond Myklebust , Anna Schumaker , Chuck Lever , NeilBrown , Olga Kornievskaia , Dai Ngo , Tom Talpey , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Christian Brauner , Benjamin Coddington , Donald Hunter , Lorenzo Bianconi , Qi Zheng , Andrew Morton , Muchun Song Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Jeff Layton X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=1369; i=jlayton@kernel.org; h=from:subject:message-id; bh=ElXBJxHoO/+5LnrW3BYnMZfLR1dfH4fwXtgt+PNtj7Q=; b=owEBbQKS/ZANAwAKAQAOaEEZVoIVAcsmYgBqKFG98mA2HmN6vZjthOxq617T80VlmQVCt2gSP tWUjr2aHdaJAjMEAAEKAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCaihRvQAKCRAADmhBGVaC FctYD/9CJX7SEDUiXBQWdaJOTrVh78wpvPKeefQoky5pgLeTaew0c+vsSVlS5lH431Q99lcABLw W8a0qWWG+zqylj4jcTkhfXQ2j2sYiesIKqib3cBBtFznav1ODQ3gYF63mM+Pc9z5rocwMD/YHEP A0B/2a8ZRz9W2g52CzOKYadkOIAmBCo+Zua/rxHAdXoTCYBBlRj9yzHvjUb1bDiS/XfUD+y5ywG kJ/8qCXafMDW4wmawltGOE6/J1NbdpaU8iSoZ2yJ3MMpMUe+NJ3dp4pqFigEHNJIm09B1EjykrQ u6Qc0QfvGQQHLOq/WM3UyE8Tev0NEW9AMcNzmo52jOoX6gw5LiEaUd/AAPZsBaQ4Ze9uzJXdlrD zJfTZUEPWbTw+FHD/NcLBtlHMZO+enfzy8hAKPDEH/PC59TleLi22GEAAgYIK1Drz9Ou7zHa5Z2 BM2AlVDMryh/T6OwHLt6I7PVSkgcllt0vStZ98D/AloQnhQgP7ThwJgvrzuhXqTmA4TlkzoZsBu Bu0Hnk/4Kk3MiE++9SvU9ZsqbZq1h1C19IA4FJg/aEf1f54ATa+XJReefW3niK6FU5c5SU0wbFp BzpLqOwa1KukjatJY9Odt6oYPqy4AuC47uL8/db4pA8y8KCmmjlX+FvGkvZvE7U3n4IScPiAXCi i+uUvP7EqMMRV6w== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 shrinker_register() precedes the INIT_LIST_HEAD loop and the drc_hashsize store. On weakly-ordered architectures (arm64, ppc), a shrinker scan can observe drc_hashsize before the bucket list heads are initialized, causing a NULL deref in the DRC shrinker callback. Move bucket initialization and the drc_hashsize store before shrinker_register() so the hash table is fully initialized before it becomes visible to the shrinker. Fixes: 8eea99a81c6f ("nfsd: dynamically allocate the nfsd-reply shrinker") Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Jeff Layton --- fs/nfsd/nfscache.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c index 154468ceccdc..18f8556d33dd 100644 --- a/fs/nfsd/nfscache.c +++ b/fs/nfsd/nfscache.c @@ -200,14 +200,14 @@ int nfsd_reply_cache_init(struct nfsd_net *nn) nn->nfsd_reply_cache_shrinker->seeks = 1; nn->nfsd_reply_cache_shrinker->private_data = nn; - shrinker_register(nn->nfsd_reply_cache_shrinker); - for (i = 0; i < hashsize; i++) { INIT_LIST_HEAD(&nn->drc_hashtbl[i].lru_head); spin_lock_init(&nn->drc_hashtbl[i].cache_lock); } nn->drc_hashsize = hashsize; + shrinker_register(nn->nfsd_reply_cache_shrinker); + return 0; out_shrinker: kvfree(nn->drc_hashtbl); -- 2.54.0