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 EBB0E15A85C; Mon, 27 May 2024 15:53:59 +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=1716825240; cv=none; b=W+b/DUMhCNUo6JObquepd0OrxPLUcTxOuZNQIRu1bvFpcic0gOdezwrxKvbgQNXSYEd4L/BxkBG7pTqGlHOHqJlEcGJRq3+lOdBzPOaUCXLGSFT1oDVVEJdAw5b2/sCgDOhQNhlAwx/aVvhugSMxCqokk2t+rf+5hjMhDMIoTlg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716825240; c=relaxed/simple; bh=t69fSFn4QBXxAEyTZrdB5V0gHZ/18lUkY7exkJBwoPI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=n7B4A6l9i8crLDdH9FWcmJLjldTW8p54O2gyGgqS2lZVtwHH9+Pb92vvv7s/2xUUrRS+p9mi08kZm/GJMVLWaYOym1bhb+hHJ/fFbD0RntZneiGIiKmEvF+3sIiQmkTwQtxu0mvR3+DCiusmHUp+T6db7axfrgO7B3fcI+2BMLg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TRyba0Qy; 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="TRyba0Qy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4FCDC32789; Mon, 27 May 2024 15:53:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716825239; bh=t69fSFn4QBXxAEyTZrdB5V0gHZ/18lUkY7exkJBwoPI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TRyba0Qy94RiD2lj5r0XFcoNmVZ0wuMtcQX+pfE+oZ9/JtIghm5Ck7oACsNHL860u ++xDEKxBEdrNdH6Dj1/fkaIo0sU46vQa7vtWUgXRBM3nrnDqaHAuU0sm9tVc5FjJT9 7wbhQXgrX/eIe8Yyy9r27T/5czD+boxuYVBZMKRx/gI7RjFeJLGEYw95h4RlF3WP44 pIQSx+SBlif6aF8IU18kpio+pd4l9qDaTB220NWiFRyV7gB0PsvWOxm9PBTFda7GnH flwwy6+VwjMtfnFjOuYJlKoZpD1EvEfYHVBwV6AEM+4FsuPzMhgjpuLrtXBNwS3Ept WPDPFKwLOz/gQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Stefan Berger , Al Viro , Mimi Zohar , Sasha Levin , roberto.sassu@huawei.com, dmitry.kasatkin@gmail.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH AUTOSEL 6.8 03/20] ima: Fix use-after-free on a dentry's dname.name Date: Mon, 27 May 2024 11:52:46 -0400 Message-ID: <20240527155349.3864778-3-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240527155349.3864778-1-sashal@kernel.org> References: <20240527155349.3864778-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.8.11 Content-Transfer-Encoding: 8bit From: Stefan Berger [ Upstream commit be84f32bb2c981ca670922e047cdde1488b233de ] ->d_name.name can change on rename and the earlier value can be freed; there are conditions sufficient to stabilize it (->d_lock on dentry, ->d_lock on its parent, ->i_rwsem exclusive on the parent's inode, rename_lock), but none of those are met at any of the sites. Take a stable snapshot of the name instead. Link: https://lore.kernel.org/all/20240202182732.GE2087318@ZenIV/ Signed-off-by: Al Viro Signed-off-by: Stefan Berger Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin --- security/integrity/ima/ima_api.c | 16 ++++++++++++---- security/integrity/ima/ima_template_lib.c | 17 ++++++++++++++--- 2 files changed, 26 insertions(+), 7 deletions(-) diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 597ea0c4d72f7..44b8161746fec 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -244,8 +244,8 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, const char *audit_cause = "failed"; struct inode *inode = file_inode(file); struct inode *real_inode = d_real_inode(file_dentry(file)); - const char *filename = file->f_path.dentry->d_name.name; struct ima_max_digest_data hash; + struct name_snapshot filename; struct kstat stat; int result = 0; int length; @@ -316,9 +316,13 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, if (file->f_flags & O_DIRECT) audit_cause = "failed(directio)"; + take_dentry_name_snapshot(&filename, file->f_path.dentry); + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, - filename, "collect_data", audit_cause, - result, 0); + filename.name.name, "collect_data", + audit_cause, result, 0); + + release_dentry_name_snapshot(&filename); } return result; } @@ -431,6 +435,7 @@ void ima_audit_measurement(struct integrity_iint_cache *iint, */ const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf) { + struct name_snapshot filename; char *pathname = NULL; *pathbuf = __getname(); @@ -444,7 +449,10 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf) } if (!pathname) { - strscpy(namebuf, path->dentry->d_name.name, NAME_MAX); + take_dentry_name_snapshot(&filename, path->dentry); + strscpy(namebuf, filename.name.name, NAME_MAX); + release_dentry_name_snapshot(&filename); + pathname = namebuf; } diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c index 6cd0add524cdc..3b2cb8f1002e6 100644 --- a/security/integrity/ima/ima_template_lib.c +++ b/security/integrity/ima/ima_template_lib.c @@ -483,7 +483,10 @@ static int ima_eventname_init_common(struct ima_event_data *event_data, bool size_limit) { const char *cur_filename = NULL; + struct name_snapshot filename; u32 cur_filename_len = 0; + bool snapshot = false; + int ret; BUG_ON(event_data->filename == NULL && event_data->file == NULL); @@ -496,7 +499,10 @@ static int ima_eventname_init_common(struct ima_event_data *event_data, } if (event_data->file) { - cur_filename = event_data->file->f_path.dentry->d_name.name; + take_dentry_name_snapshot(&filename, + event_data->file->f_path.dentry); + snapshot = true; + cur_filename = filename.name.name; cur_filename_len = strlen(cur_filename); } else /* @@ -505,8 +511,13 @@ static int ima_eventname_init_common(struct ima_event_data *event_data, */ cur_filename_len = IMA_EVENT_NAME_LEN_MAX; out: - return ima_write_template_field_data(cur_filename, cur_filename_len, - DATA_FMT_STRING, field_data); + ret = ima_write_template_field_data(cur_filename, cur_filename_len, + DATA_FMT_STRING, field_data); + + if (snapshot) + release_dentry_name_snapshot(&filename); + + return ret; } /* -- 2.43.0