From mboxrd@z Thu Jan 1 00:00:00 1970 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 C281082495; Wed, 19 Jun 2024 13:17:37 +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=1718803057; cv=none; b=nlQS1jOGhK9yw2++X5BHXHlcNNzeJnzfaM30kCMQi/9NMre4GYqfAKviRedWrGN9zdTH33TrJAfbkrojlfnef7yFzX6YFvonfEIa7Gs8hoER/l0TGueG1lizRkx69aTeMPIATuWvMVObiWY2wjBwYB4b6lqSdItSAjw+E8SF8Rg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718803057; c=relaxed/simple; bh=L5qkCdN0BQPsWfkXY4mpuvsCg/dmPWL/3nxpggf9HA4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QVfyjfdiJcN9TO369kQQnueHKWlBUO6btgkZ83i5zOJEwM7F19JnsUs+e9PYc+GGNVYaqyYHzGPL6Vgak9hR9W/C/d2yXLRhklNoTEO6P3CC/MUWGJ+83N4A6UT32E8pvD2IyhtvYXAZloH80EX/DDAl0WPf2W3nhx3an0M2Y4Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=F/NmqCOg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="F/NmqCOg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C7F1C2BBFC; Wed, 19 Jun 2024 13:17:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718803057; bh=L5qkCdN0BQPsWfkXY4mpuvsCg/dmPWL/3nxpggf9HA4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F/NmqCOgXXwm/ZRgU1ky/ttVs/REphageDVg+F7dx85AaVaMSmZr6zWW3P410d8m9 jR4Ts17StupSkQ2jK7tBJxGu9277BKmNTHxQHehAQS3JbtUg1+Emv1U5Z2CeUWTwYV YFagZKQf6o4+Rl3/WA46GR8FMvdR7s+ocjcV249k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Baokun Li , Jeff Layton , Jia Zhu , Gao Xiang , Jingbo Xu , Christian Brauner , Sasha Levin Subject: [PATCH 6.9 111/281] cachefiles: remove requests from xarray during flushing requests Date: Wed, 19 Jun 2024 14:54:30 +0200 Message-ID: <20240619125614.120741991@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240619125609.836313103@linuxfoundation.org> References: <20240619125609.836313103@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Baokun Li [ Upstream commit 0fc75c5940fa634d84e64c93bfc388e1274ed013 ] Even with CACHEFILES_DEAD set, we can still read the requests, so in the following concurrency the request may be used after it has been freed: mount | daemon_thread1 | daemon_thread2 ------------------------------------------------------------ cachefiles_ondemand_init_object cachefiles_ondemand_send_req REQ_A = kzalloc(sizeof(*req) + data_len) wait_for_completion(&REQ_A->done) cachefiles_daemon_read cachefiles_ondemand_daemon_read // close dev fd cachefiles_flush_reqs complete(&REQ_A->done) kfree(REQ_A) xa_lock(&cache->reqs); cachefiles_ondemand_select_req req->msg.opcode != CACHEFILES_OP_READ // req use-after-free !!! xa_unlock(&cache->reqs); xa_destroy(&cache->reqs) Hence remove requests from cache->reqs when flushing them to avoid accessing freed requests. Fixes: c8383054506c ("cachefiles: notify the user daemon when looking up cookie") Signed-off-by: Baokun Li Link: https://lore.kernel.org/r/20240522114308.2402121-3-libaokun@huaweicloud.com Acked-by: Jeff Layton Reviewed-by: Jia Zhu Reviewed-by: Gao Xiang Reviewed-by: Jingbo Xu Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin --- fs/cachefiles/daemon.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c index 6465e25742309..ccb7b707ea4b7 100644 --- a/fs/cachefiles/daemon.c +++ b/fs/cachefiles/daemon.c @@ -159,6 +159,7 @@ static void cachefiles_flush_reqs(struct cachefiles_cache *cache) xa_for_each(xa, index, req) { req->error = -EIO; complete(&req->done); + __xa_erase(xa, index); } xa_unlock(xa); -- 2.43.0