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 2880C1A5A4; Fri, 24 Nov 2023 19:13:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="voHUAZnN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AAE83C433C8; Fri, 24 Nov 2023 19:13:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700853202; bh=OhTvoJYc+Kav5iXlV/c3GKgbDsCfVhL0V6hChjDbeW4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=voHUAZnNX12nBVMftaBNvw1YrvKTfrl2kNCZS3MI4ltGnsQ6yRjECXTDNxqJeLwhn AAzjA1kEo25wGPU+IVCcx9U/+gePDMNbF6nrwoO/nH7WdWCY8uHu3lEPuYyPgcL+lO 115UqZov2iyUg+hVTFddWBSgiSaebZnhLBplBMpg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, felix , Trond Myklebust , Sasha Levin Subject: [PATCH 5.15 094/297] SUNRPC: Fix RPC client cleaned up the freed pipefs dentries Date: Fri, 24 Nov 2023 17:52:16 +0000 Message-ID: <20231124172003.536764707@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231124172000.087816911@linuxfoundation.org> References: <20231124172000.087816911@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ 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: Sasha Levin --- 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 9fcf5ffc4f9ad..71ec22b1df860 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -83,6 +83,7 @@ struct rpc_clnt { }; const struct cred *cl_cred; unsigned int cl_max_connect; /* max number of transports not to the same IP */ + struct super_block *pipefs_sb; }; /* diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index fc37f314a09dd..af1ca707c3d35 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -111,7 +111,8 @@ 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); } } @@ -151,6 +152,8 @@ 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)) -- 2.42.0