From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8BFA1C369D7 for ; Thu, 24 Apr 2025 12:46:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 043A06B00AD; Thu, 24 Apr 2025 08:46:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F0AB76B00AE; Thu, 24 Apr 2025 08:46:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D84BF6B00AF; Thu, 24 Apr 2025 08:46:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id B450E6B00AD for ; Thu, 24 Apr 2025 08:46:55 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 2BA06120265 for ; Thu, 24 Apr 2025 12:46:57 +0000 (UTC) X-FDA: 83368912074.12.DA4ED1B Received: from mail-qv1-f44.google.com (mail-qv1-f44.google.com [209.85.219.44]) by imf22.hostedemail.com (Postfix) with ESMTP id 6F264C0004 for ; Thu, 24 Apr 2025 12:46:55 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=Mmvx1NLU; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf22.hostedemail.com: domain of stephen.smalley.work@gmail.com designates 209.85.219.44 as permitted sender) smtp.mailfrom=stephen.smalley.work@gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1745498815; a=rsa-sha256; cv=none; b=ZBtV2olmHE77E/vlMQX+OOYxiT3VpbCL+yO/0Cyj61B2Qqz9hY4t1FczRRXH+D09tymA5B uoGFkSyIwkISB6RYcOpEDEIVYZBx3bdBDLmgS1bqTNsilT5ofkqhVZgfkfDO0FfrlJESXo 8/sfciwCAB5eKSfmNPVmRtO14cR72xE= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=Mmvx1NLU; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf22.hostedemail.com: domain of stephen.smalley.work@gmail.com designates 209.85.219.44 as permitted sender) smtp.mailfrom=stephen.smalley.work@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1745498815; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:references:dkim-signature; bh=fYM/9Ory8tzfg3Kpjz+Y35nva+i71yk+zvmGNY+Byso=; b=HDvCpOgUsJvKQm73/XKcuktlh6a0Pa2dmzcT5W8b8itJOF/7S9jW7sYTDl82OD7Sxuxve8 bvoPNuO17xK1y7/UjZKtB7HaP9tRF65c1Tvyhkca2CRVDhZdFMvOTVb7kCFzahMIojQp5I wJawNXfA71RSmFCqe0tCfqndTqGpaso= Received: by mail-qv1-f44.google.com with SMTP id 6a1803df08f44-6f0c30a1ca3so11695806d6.1 for ; Thu, 24 Apr 2025 05:46:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1745498814; x=1746103614; darn=kvack.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=fYM/9Ory8tzfg3Kpjz+Y35nva+i71yk+zvmGNY+Byso=; b=Mmvx1NLU2+vYC1/0go179bqJT1K9OOpvD9jx2qHU7lITDzr8LZAwycvZS8rJ8+rete Op2sRaBkQhi4nH5MQkh+P+TqQm2jxvHMTOaa0tpK4fKT7HxjCH38YqgpIySkxYdMWWwK DEnrYDSGhYqU9MIJRoANSle4EygaRls4S3lltpbIiR2A4YQR3RQv8ErIWge0+568V5v6 ZgRNQGcjpfdBwc4aRXxv5saRWOvgb45lmjL4BPCJiop2cVYwdCTyN2xU8fkFHeOX/DHK +xALEhfLqtlrA1wIb1qlr2DHsfasuA3EgOJHnRE3ecthqBygM6PDkbDzYkPfvErJmlTG KBaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1745498814; x=1746103614; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=fYM/9Ory8tzfg3Kpjz+Y35nva+i71yk+zvmGNY+Byso=; b=ZtcUko2P7C2ofQX3ALBGfyiH12I+r8Xpd5C/lJ7SJsB7OAwHF+B4mZL3+hzyDrUYf6 zIjoxHjlYVlCzwjBtbg73XD6CjI9w/DVMm/oF5gWk4hMqOR8otz3R5Fl17N5QcEG5eo+ 0k7rVWriWkJCfszsKfygE+iG2mFwts1FA25oiIBuKF4d0wBQ9lzCxfdc8eRHLEOM53EI nERnP7hwcEgomof6+iVyU/HrjbImFdBfCnzx52wlv7s38Mkpfg0ejGMp073XmOui0nfm 2fqO9v8N94y95GUP2MFxYqf+CG/M7Ft/sTlBbL4sP0biXgMjCR4uWihZbWarMv+OnP2K AJgA== X-Forwarded-Encrypted: i=1; AJvYcCXsUIYxtDFs79Ox/b24nH2wmMQXoPIFt7zjGlkt2vreTNY0dycfdWE7oYthEHoHwNPthjSzmAC/bQ==@kvack.org X-Gm-Message-State: AOJu0YwhxdA6kDzk1Jef46BsP0eke9HYy6dBwIIhbzZRqwEYKhnJLn5e GBJ4LaEyj11RUjwheBg+UwLcEqGRezG8pYENGvPItJlYgdowBCZk X-Gm-Gg: ASbGncuFnqCcT1Y3WRvgJY79NhuThPmQQUwzmFumLPonNuCQL3fAghj88zcBq4bA5vR 8R2M6ZOfrxV+jEACDTBX7wBxaVYsyJuqUZJp/VPXEmd8CG/f9glZqJd84rfZaFKjGOyQ6xhu+Ba lgNR8df8gMuaC0VsyEZLdREY2Yk0wPQUZYT1Foonz7Oe32hB8GQTzznL8yQRESDZcJXT17mX4SR /0lBGJLMip4vqbQlr9NKoSj2zr6UBXyfyAFTWRfwvStWobQtqqLoSZDXk+RJv9l5X2db0n+BIji IbkDd9oRMXQElRz3s21OvsTtZTR8BRFZYXAHY7mgdK7r4F+VjkwmO3jn/kLeQi2oNDyFX5Rzg0w bZdhpy9tWY4f9o0xifXjTAM9osRxooEHOlYqidWGwlqcj5yqmjNchdmOwMvWNRbF2U84Y X-Google-Smtp-Source: AGHT+IGPS/dXTlSAUgqMyWGzy05kAtY0v8SaSKHbVmoNWKqJ530g0u4yrhTVutuLdWk4A0POPvlmzw== X-Received: by 2002:a05:6214:21ef:b0:6e8:97f6:3229 with SMTP id 6a1803df08f44-6f4bfbd59b7mr44609636d6.16.1745498814256; Thu, 24 Apr 2025 05:46:54 -0700 (PDT) Received: from fuse-fed34-svr.evoforge.org (ec2-52-70-167-183.compute-1.amazonaws.com. [52.70.167.183]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6f4c08ef1a6sm8960636d6.7.2025.04.24.05.46.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Apr 2025 05:46:53 -0700 (PDT) From: Stephen Smalley To: paul@paul-moore.com Cc: omosnace@redhat.com, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, Stephen Smalley , Greg Kroah-Hartman , Tejun Heo , Alexander Viro , Christian Brauner , Jan Kara , Hugh Dickins , Baolin Wang , Andrew Morton , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH] vfs,shmem,kernfs: fix listxattr to include security.* xattrs Date: Thu, 24 Apr 2025 08:46:43 -0400 Message-ID: <20250424124644.4413-1-stephen.smalley.work@gmail.com> X-Mailer: git-send-email 2.49.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 6F264C0004 X-Stat-Signature: sib9s6tohb53hmm14qk7xtwuh1eo9whi X-HE-Tag: 1745498815-476782 X-HE-Meta: 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 Frxg4fZG 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: The vfs has long had a fallback to obtain the security.* xattrs from the LSM when the filesystem does not implement its own listxattr, but shmem/tmpfs and kernfs later gained their own xattr handlers to support other xattrs. Unfortunately, as a side effect, tmpfs and kernfs-based filesystems like sysfs no longer return the synthetic security.* xattr names via listxattr unless they are explicitly set by userspace or initially set upon inode creation after policy load. coreutils has recently switched from unconditionally invoking getxattr for security.* for ls -Z via libselinux to only doing so if listxattr returns the xattr name, breaking ls -Z of such inodes. Before: $ getfattr -m.* /run/initramfs $ getfattr -m.* /sys/kernel/fscaps After: $ getfattr -m.* /run/initramfs security.selinux $ getfattr -m.* /sys/kernel/fscaps security.selinux Link: https://lore.kernel.org/selinux/CAFqZXNtF8wDyQajPCdGn=iOawX4y77ph0EcfcqcUUj+T87FKyA@mail.gmail.com/ Link: https://lore.kernel.org/selinux/20250423175728.3185-2-stephen.smalley.work@gmail.com/ Signed-off-by: Stephen Smalley --- fs/kernfs/inode.c | 8 +++++++- fs/xattr.c | 13 +++++++++++++ mm/shmem.c | 8 +++++++- 3 files changed, 27 insertions(+), 2 deletions(-) diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c index b83054da68b3..8fd69e48d32d 100644 --- a/fs/kernfs/inode.c +++ b/fs/kernfs/inode.c @@ -140,12 +140,18 @@ ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size) { struct kernfs_node *kn = kernfs_dentry_node(dentry); struct kernfs_iattrs *attrs; + ssize_t sz; attrs = kernfs_iattrs(kn); if (!attrs) return -ENOMEM; - return simple_xattr_list(d_inode(dentry), &attrs->xattrs, buf, size); + sz = simple_xattr_list(d_inode(dentry), &attrs->xattrs, buf, size); + if (sz >= 0 && sz <= size) + sz += security_inode_listsecurity(d_inode(dentry), + buf ? buf + sz : NULL, + size - sz); + return sz; } static inline void set_default_inode_attr(struct inode *inode, umode_t mode) diff --git a/fs/xattr.c b/fs/xattr.c index 02bee149ad96..68ac91d0dbc3 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -1428,6 +1428,15 @@ static bool xattr_is_trusted(const char *name) return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN); } +static bool xattr_is_maclabel(const char *name) +{ + const char *suffix = name + XATTR_SECURITY_PREFIX_LEN; + + return !strncmp(name, XATTR_SECURITY_PREFIX, + XATTR_SECURITY_PREFIX_LEN) && + security_ismaclabel(suffix); +} + /** * simple_xattr_list - list all xattr objects * @inode: inode from which to get the xattrs @@ -1468,6 +1477,10 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, if (!trusted && xattr_is_trusted(xattr->name)) continue; + /* skip MAC labels; these are provided by LSM separately */ + if (xattr_is_maclabel(xattr->name)) + continue; + err = xattr_list_one(&buffer, &remaining_size, xattr->name); if (err) break; diff --git a/mm/shmem.c b/mm/shmem.c index 99327c30507c..69f664668a3a 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -4372,7 +4372,13 @@ static const struct xattr_handler * const shmem_xattr_handlers[] = { static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size) { struct shmem_inode_info *info = SHMEM_I(d_inode(dentry)); - return simple_xattr_list(d_inode(dentry), &info->xattrs, buffer, size); + ssize_t sz = simple_xattr_list(d_inode(dentry), &info->xattrs, buffer, + size); + if (sz >= 0 && sz <= size) + sz += security_inode_listsecurity(d_inode(dentry), + buffer ? buffer + sz : NULL, + size - sz); + return sz; } #endif /* CONFIG_TMPFS_XATTR */ -- 2.49.0