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 EFA7739FC2; Fri, 24 Nov 2023 18:17:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="byRUsH1Y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 720D9C433C9; Fri, 24 Nov 2023 18:17:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700849875; bh=wpucexgHopoCabVA0DmZorAZVOpP+MVwjvsDyMy6h7c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=byRUsH1YjWni8fB8H7Ftkrg3dv+xVWK1Et6vGOIfLqTUSzdRPk6rF6Glg/3CWnyY9 Q3Tx1hc0UkwxDJWbibGZqCkrYlZnxDMh3aT2FcX8DqBiRukjjJe6vl26h4sX1ysxMq 7rAPHgmeSdsN83HQ6TKh1YaJcHL0OQBRFg0GcAik= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Amir Goldstein , Mimi Zohar , syzbot+b42fe626038981fb7bfa@syzkaller.appspotmail.com Subject: [PATCH 6.6 348/530] ima: annotate iint mutex to avoid lockdep false positive warnings Date: Fri, 24 Nov 2023 17:48:34 +0000 Message-ID: <20231124172038.610622291@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231124172028.107505484@linuxfoundation.org> References: <20231124172028.107505484@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Amir Goldstein commit e044374a8a0a99e46f4e6d6751d3042b6d9cc12e upstream. It is not clear that IMA should be nested at all, but as long is it measures files both on overlayfs and on underlying fs, we need to annotate the iint mutex to avoid lockdep false positives related to IMA + overlayfs, same as overlayfs annotates the inode mutex. Reported-and-tested-by: syzbot+b42fe626038981fb7bfa@syzkaller.appspotmail.com Signed-off-by: Amir Goldstein Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman --- security/integrity/iint.c | 48 +++++++++++++++++++++++++++++++++++----------- 1 file changed, 37 insertions(+), 11 deletions(-) --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -66,9 +66,32 @@ struct integrity_iint_cache *integrity_i return iint; } -static void iint_free(struct integrity_iint_cache *iint) +#define IMA_MAX_NESTING (FILESYSTEM_MAX_STACK_DEPTH+1) + +/* + * It is not clear that IMA should be nested at all, but as long is it measures + * files both on overlayfs and on underlying fs, we need to annotate the iint + * mutex to avoid lockdep false positives related to IMA + overlayfs. + * See ovl_lockdep_annotate_inode_mutex_key() for more details. + */ +static inline void iint_lockdep_annotate(struct integrity_iint_cache *iint, + struct inode *inode) +{ +#ifdef CONFIG_LOCKDEP + static struct lock_class_key iint_mutex_key[IMA_MAX_NESTING]; + + int depth = inode->i_sb->s_stack_depth; + + if (WARN_ON_ONCE(depth < 0 || depth >= IMA_MAX_NESTING)) + depth = 0; + + lockdep_set_class(&iint->mutex, &iint_mutex_key[depth]); +#endif +} + +static void iint_init_always(struct integrity_iint_cache *iint, + struct inode *inode) { - kfree(iint->ima_hash); iint->ima_hash = NULL; iint->version = 0; iint->flags = 0UL; @@ -80,6 +103,14 @@ static void iint_free(struct integrity_i iint->ima_creds_status = INTEGRITY_UNKNOWN; iint->evm_status = INTEGRITY_UNKNOWN; iint->measured_pcrs = 0; + mutex_init(&iint->mutex); + iint_lockdep_annotate(iint, inode); +} + +static void iint_free(struct integrity_iint_cache *iint) +{ + kfree(iint->ima_hash); + mutex_destroy(&iint->mutex); kmem_cache_free(iint_cache, iint); } @@ -104,6 +135,8 @@ struct integrity_iint_cache *integrity_i if (!iint) return NULL; + iint_init_always(iint, inode); + write_lock(&integrity_iint_lock); p = &integrity_iint_tree.rb_node; @@ -153,25 +186,18 @@ void integrity_inode_free(struct inode * iint_free(iint); } -static void init_once(void *foo) +static void iint_init_once(void *foo) { struct integrity_iint_cache *iint = (struct integrity_iint_cache *) foo; memset(iint, 0, sizeof(*iint)); - iint->ima_file_status = INTEGRITY_UNKNOWN; - iint->ima_mmap_status = INTEGRITY_UNKNOWN; - iint->ima_bprm_status = INTEGRITY_UNKNOWN; - iint->ima_read_status = INTEGRITY_UNKNOWN; - iint->ima_creds_status = INTEGRITY_UNKNOWN; - iint->evm_status = INTEGRITY_UNKNOWN; - mutex_init(&iint->mutex); } static int __init integrity_iintcache_init(void) { iint_cache = kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache), - 0, SLAB_PANIC, init_once); + 0, SLAB_PANIC, iint_init_once); return 0; } DEFINE_LSM(integrity) = {