From patchwork Fri Nov 8 22:13:05 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trond Myklebust X-Patchwork-Id: 13868998 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 230B21F26DD for ; Fri, 8 Nov 2024 22:13:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731103988; cv=none; b=dc0wgzu0lIN056l7OuZzgChIs135EKfPxOcA/fVp7P4fFdKXlN/Um9KPWJjjDiw/wIQJrYr1AAtngycG4+cnE891+eJwxzE9vRxNaTplf1cFi3RGffG3d+rz+DO7an4cEFfyn1LtMO7GFn2/esYucMlFZJEnADwozlzSOnH30Fc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731103988; c=relaxed/simple; bh=Xtt7P8/TFaw+mClV10FcQQ/Lr/2pnOW7p0eTzPh9kAk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jjLiOC/nm7u1B4+badIUElq74XVjjV2dvtr5Er96FEFxCRK43pfc8dF1rVEStgaF35mC10r1IukXgPpQIXkIBf9rCxF0yaABke8qL2Y4Ut1kpGiXUo4BF7DPGGEvkwOS281qo7aZx9SHIW1DFKAvqQCO3FFj1nyRgIyS9//rgz4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XenrAWbk; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="XenrAWbk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8DA7FC4CED2; Fri, 8 Nov 2024 22:13:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1731103987; bh=Xtt7P8/TFaw+mClV10FcQQ/Lr/2pnOW7p0eTzPh9kAk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XenrAWbkoFrcmcmWzdVv/zUQMgB7BPdP/YhlpOixxrtb5k183UIqftG9HUFTavxqP j31zPKEVuzTkC5g4efgEOMmxVeuy5rq+dH8F0bvIHtsufyhVKazRtrh4OSOgShFSif kBJmbEC8YJaI1Z8TV8B6KFBeAuqOzuvUZYDl+EslHSKEByBTw1wu9r4lCzCf6AEcJF rvtzDziSvCq9SD4Fnnct8RNcjshD+Wht+WFsu88+wiDS1sXVZUzenSyVC95eMXxTHa 9PebPC1SZoiw5PuezPyJzhqm3zPR3+h04+YJcjzMPQmZCx1xwSsulgXXkzTLKRJi/Z dl8JVaB7j8FfQ== From: trondmy@kernel.org To: Yang Erkun Cc: linux-nfs@vger.kernel.org Subject: [PATCH 2/2] NFSv4.0: Fix a use-after-free problem in the asynchronous open() Date: Fri, 8 Nov 2024 17:13:05 -0500 Message-ID: X-Mailer: git-send-email 2.47.0 In-Reply-To: <5527548df9be8ce76ed31ad0ea6520908533b4fe.1731103952.git.trond.myklebust@hammerspace.com> References: <5527548df9be8ce76ed31ad0ea6520908533b4fe.1731103952.git.trond.myklebust@hammerspace.com> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Trond Myklebust Yang Erkun reports that when two threads are opening files at the same time, and are forced to abort before a reply is seen, then the call to nfs_release_seqid() in nfs4_opendata_free() can result in a use-after-free of the pointer to the defunct rpc task of the other thread. The fix is to ensure that if the RPC call is aborted before the call to nfs_wait_on_sequence() is complete, then we must call nfs_release_seqid() in nfs4_open_release() before the rpc_task is freed. Reported-by: Yang Erkun Fixes: 24ac23ab88df ("NFSv4: Convert open() into an asynchronous RPC call") Signed-off-by: Trond Myklebust Reviewed-by: Yang Erkun --- fs/nfs/nfs4proc.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 9d40319e063d..405f17e6e0b4 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2603,12 +2603,14 @@ static void nfs4_open_release(void *calldata) struct nfs4_opendata *data = calldata; struct nfs4_state *state = NULL; + /* In case of error, no cleanup! */ + if (data->rpc_status != 0 || !data->rpc_done) { + nfs_release_seqid(data->o_arg.seqid); + goto out_free; + } /* If this request hasn't been cancelled, do nothing */ if (!data->cancelled) goto out_free; - /* In case of error, no cleanup! */ - if (data->rpc_status != 0 || !data->rpc_done) - goto out_free; /* In case we need an open_confirm, no cleanup! */ if (data->o_res.rflags & NFS4_OPEN_RESULT_CONFIRM) goto out_free;