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 99C9B17D23C; Sun, 24 Mar 2024 23:43:40 +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=1711323821; cv=none; b=FowizFsJZ7cb/9TnQ/bIwUtZ/iqfyqd5Do0j9kBfYNGTla6G5mA1maKvrawVlEdhaaqdpCE5KHlb22fzbmJA9AwGofHnq5jBcstqOssGLw1yAa9UMT4H12WjsIgFyKvNVEI7PSkNGrK2raNgSEe46S6xVY6Lrrt3+Q8JaZZXBUc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711323821; c=relaxed/simple; bh=OEpuwg0q9vOOoCyK9mvaQjRn/3FyP2kLhLivgjOMeNw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qeqG99JqUzAnZ5KJQ42UXtVV1xuX949TQu6CLUfxddpqi+Qs8Xccmv4lBLfmrUmzUPaB6j10uzkwyzlvvYqSu7GqEwerhDw3QjfiMmEd0J14GONSAi12bYGL9QBfHCeJDrpmy1aq/CSX8QdFDxwbLGA3BcjVfG7Ayln4cBFZQLo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KxVpAA1g; 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="KxVpAA1g" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD4B5C433C7; Sun, 24 Mar 2024 23:43:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711323820; bh=OEpuwg0q9vOOoCyK9mvaQjRn/3FyP2kLhLivgjOMeNw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KxVpAA1gdQ5fZjWDGVYmk/lMcVsPdvRGv8lrplZCe3uWTwXnafXmq8o/QEW402BJz FfH2aJ1oiV9FXx25C6ITsXvs9Hu7rByJ3IAErX93F7JseTgECAi7mw7zHeF3yYDTrS Cnbf7X6qDw9E/iAphiR+lGpZ5BnMIeQXxGZ9ix5UHKtUULK52eBc++/oCeChKvzJcu 2XVCaS5osYglLk32ndFoO91/d3bdMHwYdhC6x3GiSDqdslZOhC92vXyacgbbSb3Av9 rkKTP2bw8KB4Ta36c68ITBASQu0F78Y6zyb4xy2XvgdXnJcdcyfr5J+GLAGodA8WZ4 EyqfdzKvsrQSA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jorge Mora , Jorge Mora , Benjamin Coddington , Trond Myklebust , Sasha Levin Subject: [PATCH 5.10 199/238] NFSv4.2: fix nfs4_listxattr kernel BUG at mm/usercopy.c:102 Date: Sun, 24 Mar 2024 19:39:47 -0400 Message-ID: <20240324234027.1354210-200-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324234027.1354210-1-sashal@kernel.org> References: <20240324234027.1354210-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Jorge Mora [ Upstream commit 251a658bbfceafb4d58c76b77682c8bf7bcfad65 ] A call to listxattr() with a buffer size = 0 returns the actual size of the buffer needed for a subsequent call. When size > 0, nfs4_listxattr() does not return an error because either generic_listxattr() or nfs4_listxattr_nfs4_label() consumes exactly all the bytes then size is 0 when calling nfs4_listxattr_nfs4_user() which then triggers the following kernel BUG: [ 99.403778] kernel BUG at mm/usercopy.c:102! [ 99.404063] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP [ 99.408463] CPU: 0 PID: 3310 Comm: python3 Not tainted 6.6.0-61.fc40.aarch64 #1 [ 99.415827] Call trace: [ 99.415985] usercopy_abort+0x70/0xa0 [ 99.416227] __check_heap_object+0x134/0x158 [ 99.416505] check_heap_object+0x150/0x188 [ 99.416696] __check_object_size.part.0+0x78/0x168 [ 99.416886] __check_object_size+0x28/0x40 [ 99.417078] listxattr+0x8c/0x120 [ 99.417252] path_listxattr+0x78/0xe0 [ 99.417476] __arm64_sys_listxattr+0x28/0x40 [ 99.417723] invoke_syscall+0x78/0x100 [ 99.417929] el0_svc_common.constprop.0+0x48/0xf0 [ 99.418186] do_el0_svc+0x24/0x38 [ 99.418376] el0_svc+0x3c/0x110 [ 99.418554] el0t_64_sync_handler+0x120/0x130 [ 99.418788] el0t_64_sync+0x194/0x198 [ 99.418994] Code: aa0003e3 d000a3e0 91310000 97f49bdb (d4210000) Issue is reproduced when generic_listxattr() returns 'system.nfs4_acl', thus calling lisxattr() with size = 16 will trigger the bug. Add check on nfs4_listxattr() to return ERANGE error when it is called with size > 0 and the return value is greater than size. Fixes: 012a211abd5d ("NFSv4.2: hook in the user extended attribute handlers") Signed-off-by: Jorge Mora Reviewed-by: Benjamin Coddington Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/nfs4proc.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 7c3c96ed60853..8e546e6a56198 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -10370,29 +10370,33 @@ const struct nfs4_minor_version_ops *nfs_v4_minor_ops[] = { static ssize_t nfs4_listxattr(struct dentry *dentry, char *list, size_t size) { ssize_t error, error2, error3; + size_t left = size; - error = generic_listxattr(dentry, list, size); + error = generic_listxattr(dentry, list, left); if (error < 0) return error; if (list) { list += error; - size -= error; + left -= error; } - error2 = nfs4_listxattr_nfs4_label(d_inode(dentry), list, size); + error2 = nfs4_listxattr_nfs4_label(d_inode(dentry), list, left); if (error2 < 0) return error2; if (list) { list += error2; - size -= error2; + left -= error2; } - error3 = nfs4_listxattr_nfs4_user(d_inode(dentry), list, size); + error3 = nfs4_listxattr_nfs4_user(d_inode(dentry), list, left); if (error3 < 0) return error3; - return error + error2 + error3; + error += error2 + error3; + if (size && error > size) + return -ERANGE; + return error; } static void nfs4_enable_swap(struct inode *inode) -- 2.43.0