From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-fw-9102.amazon.com (smtp-fw-9102.amazon.com [207.171.184.29]) (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 8CFF9172BA6 for ; Mon, 15 Jul 2024 13:13:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=207.171.184.29 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721049189; cv=none; b=ixlEvkkOnqGfuv246hPyANrvIyooeqQOxl5ph1znne8pWuTaKfoXvqnqimDRM3o/sYlnLlMF0ClxrKV7u0DRAaCcEeS05N9qBlreLeSob6FPCrh1MdDAKgBhdF/sWqHfz0scivhtOyhOnfkM7RS2fA06EzqQZaJIblu6sOwj8H4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721049189; c=relaxed/simple; bh=iuKw2nfeajIZ1IIr1XxrlOsHGP+q8cBEXEzP5ZweiLU=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=tAQtNa2yxYxsJ2s+u/CiDJ+dQiMAbaMllphGP/3GvqzXgbR0nTtLigt5gfwrJLf0AxFKnCd9VGJufXH8ep58nOTNdtpB4Au1JDOepwoiPBQKW9ysQCzVruzOTt03q6KkaZGeYtTOIgyw0h8RJtDLmdwaI/gr7X6//CFr76sD7CE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.com; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b=PXdN8Nd9; arc=none smtp.client-ip=207.171.184.29 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="PXdN8Nd9" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1721049188; x=1752585188; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=edMKxdO6Wjb5VMFY+7ZK4kkm1OeWxEkpLqEE8sobS8s=; b=PXdN8Nd9Y+EfZgZ8v41hO1ziq1jRmpSTcvIligZuMDVP49hZREM2Tw8I aCLh4JfPLuDyelnnadAf1wdKETnDJCG1/6sQOqnYsVGZy/egetB+WYDed jy4uuKm2tRE3ERtnnHR3PEl90Z2ryZ7jItKlMCiHYyfTHm0HvzMXQe5nE Q=; X-IronPort-AV: E=Sophos;i="6.09,210,1716249600"; d="scan'208";a="435049954" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO smtpout.prod.us-east-1.prod.farcaster.email.amazon.dev) ([10.25.36.214]) by smtp-border-fw-9102.sea19.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jul 2024 13:13:00 +0000 Received: from EX19MTAUEB002.ant.amazon.com [10.0.44.209:52954] by smtpin.naws.us-east-1.prod.farcaster.email.amazon.dev [10.0.13.24:2525] with esmtp (Farcaster) id 97281965-9e02-4ec0-94eb-f73544a19acd; Mon, 15 Jul 2024 13:12:59 +0000 (UTC) X-Farcaster-Flow-ID: 97281965-9e02-4ec0-94eb-f73544a19acd Received: from EX19MTAUEC001.ant.amazon.com (10.252.135.222) by EX19MTAUEB002.ant.amazon.com (10.252.135.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.34; Mon, 15 Jul 2024 13:12:58 +0000 Received: from dev-dsk-hagarhem-1b-b868d8d5.eu-west-1.amazon.com (10.253.65.58) by mail-relay.amazon.com (10.252.135.200) with Microsoft SMTP Server id 15.2.1258.34 via Frontend Transport; Mon, 15 Jul 2024 13:12:58 +0000 Received: by dev-dsk-hagarhem-1b-b868d8d5.eu-west-1.amazon.com (Postfix, from userid 23002382) id 465BA20D56; Mon, 15 Jul 2024 13:12:58 +0000 (UTC) From: Hagar Hemdan To: CC: , felix , Trond Myklebust , Hagar Hemdan Subject: [PATCH 4.14] SUNRPC: Fix RPC client cleaned up the freed pipefs dentries Date: Mon, 15 Jul 2024 13:12:57 +0000 Message-ID: <20240715131257.22428-1-hagarhem@amazon.com> X-Mailer: git-send-email 2.40.1 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain From: felix [ Upstream commit bfca5fb4e97c46503ddfc582335917b0cc228264 ] RPC client pipefs dentries cleanup is in separated rpc_remove_pipedir() workqueue,which takes care about pipefs superblock locking. In some special scenarios, when kernel frees the pipefs sb of the current client and immediately alloctes a new pipefs sb, rpc_remove_pipedir function would misjudge the existence of pipefs sb which is not the one it used to hold. As a result, the rpc_remove_pipedir would clean the released freed pipefs dentries. To fix this issue, rpc_remove_pipedir should check whether the current pipefs sb is consistent with the original pipefs sb. This error can be catched by KASAN: ========================================================= [ 250.497700] BUG: KASAN: slab-use-after-free in dget_parent+0x195/0x200 [ 250.498315] Read of size 4 at addr ffff88800a2ab804 by task kworker/0:18/106503 [ 250.500549] Workqueue: events rpc_free_client_work [ 250.501001] Call Trace: [ 250.502880] kasan_report+0xb6/0xf0 [ 250.503209] ? dget_parent+0x195/0x200 [ 250.503561] dget_parent+0x195/0x200 [ 250.503897] ? __pfx_rpc_clntdir_depopulate+0x10/0x10 [ 250.504384] rpc_rmdir_depopulate+0x1b/0x90 [ 250.504781] rpc_remove_client_dir+0xf5/0x150 [ 250.505195] rpc_free_client_work+0xe4/0x230 [ 250.505598] process_one_work+0x8ee/0x13b0 ... [ 22.039056] Allocated by task 244: [ 22.039390] kasan_save_stack+0x22/0x50 [ 22.039758] kasan_set_track+0x25/0x30 [ 22.040109] __kasan_slab_alloc+0x59/0x70 [ 22.040487] kmem_cache_alloc_lru+0xf0/0x240 [ 22.040889] __d_alloc+0x31/0x8e0 [ 22.041207] d_alloc+0x44/0x1f0 [ 22.041514] __rpc_lookup_create_exclusive+0x11c/0x140 [ 22.041987] rpc_mkdir_populate.constprop.0+0x5f/0x110 [ 22.042459] rpc_create_client_dir+0x34/0x150 [ 22.042874] rpc_setup_pipedir_sb+0x102/0x1c0 [ 22.043284] rpc_client_register+0x136/0x4e0 [ 22.043689] rpc_new_client+0x911/0x1020 [ 22.044057] rpc_create_xprt+0xcb/0x370 [ 22.044417] rpc_create+0x36b/0x6c0 ... [ 22.049524] Freed by task 0: [ 22.049803] kasan_save_stack+0x22/0x50 [ 22.050165] kasan_set_track+0x25/0x30 [ 22.050520] kasan_save_free_info+0x2b/0x50 [ 22.050921] __kasan_slab_free+0x10e/0x1a0 [ 22.051306] kmem_cache_free+0xa5/0x390 [ 22.051667] rcu_core+0x62c/0x1930 [ 22.051995] __do_softirq+0x165/0x52a [ 22.052347] [ 22.052503] Last potentially related work creation: [ 22.052952] kasan_save_stack+0x22/0x50 [ 22.053313] __kasan_record_aux_stack+0x8e/0xa0 [ 22.053739] __call_rcu_common.constprop.0+0x6b/0x8b0 [ 22.054209] dentry_free+0xb2/0x140 [ 22.054540] __dentry_kill+0x3be/0x540 [ 22.054900] shrink_dentry_list+0x199/0x510 [ 22.055293] shrink_dcache_parent+0x190/0x240 [ 22.055703] do_one_tree+0x11/0x40 [ 22.056028] shrink_dcache_for_umount+0x61/0x140 [ 22.056461] generic_shutdown_super+0x70/0x590 [ 22.056879] kill_anon_super+0x3a/0x60 [ 22.057234] rpc_kill_sb+0x121/0x200 Fixes: 0157d021d23a ("SUNRPC: handle RPC client pipefs dentries by network namespace aware routines") Signed-off-by: felix Signed-off-by: Trond Myklebust Signed-off-by: Hagar Hemdan --- include/linux/sunrpc/clnt.h | 1 + net/sunrpc/clnt.c | 5 ++++- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index 166fc4e76df6..b324adc24bee 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -70,6 +70,7 @@ struct rpc_clnt { struct dentry *cl_debugfs; /* debugfs directory */ #endif struct rpc_xprt_iter cl_xpi; + struct super_block *pipefs_sb; }; /* diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index de917d45e512..82994e3c0fd0 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -112,7 +112,8 @@ static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt) pipefs_sb = rpc_get_sb_net(net); if (pipefs_sb) { - __rpc_clnt_remove_pipedir(clnt); + if (pipefs_sb == clnt->pipefs_sb) + __rpc_clnt_remove_pipedir(clnt); rpc_put_sb_net(net); } } @@ -152,6 +153,8 @@ rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt) { struct dentry *dentry; + clnt->pipefs_sb = pipefs_sb; + if (clnt->cl_program->pipe_dir_name != NULL) { dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt); if (IS_ERR(dentry)) -- 2.40.1