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 5641312FB31; Wed, 19 Jun 2024 13:10:56 +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=1718802656; cv=none; b=jiH26SXEIY/7eiCKJ+FEvf5F41kJJAekabEfg3lZ02kJaIVhqIxSaGbBsx9B4+KVY1bnB6OOIQTQuoqhK+DyFZUpHK9bt1/x4Anh/LsKt1RtK9Or9Wa+sS3TU8Hl3eO6pyCZn3BJNAvHaYbVoy1PNzfnmU9/AfQuLcSq98M3jwE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718802656; c=relaxed/simple; bh=JOUq0QUVBb43MuQD6iKV7WA/VnfXy6sJPjprGVOHn4w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=O0y8WLayEXoazevodJrd6jnv1sz+EwllmaHfSAQAXoz2uCbsXGWeavQRR2hlQMEbCoIuXpmZe1QktvyICOWIV5thFYDXWFjCEtkBJz2i1cXDNmCXGK0ojVijkqW0ylkaqunP4YQcPyPcA3SonBIeQR2cS8xp+ikpZziIDITSqdI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Ugj5vr/+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Ugj5vr/+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2D5FC32786; Wed, 19 Jun 2024 13:10:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718802656; bh=JOUq0QUVBb43MuQD6iKV7WA/VnfXy6sJPjprGVOHn4w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ugj5vr/+C+ZgLuIGZ21VnEhXM27PHztcy+qXTCc74rKgIgUFGV08n3j4sholP6ApP kXVTH+1NloOSOcZmpPKz6aVep5MagTgIKbcKQhZWIvCDrHDA+b5OJRgF5hXDrvnLKs 6cM/xuxmRv6C28soudNcipU9tGDsMM5AF69gIDZw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Al Viro , Stefan Berger , Mimi Zohar Subject: [PATCH 6.6 256/267] ima: Fix use-after-free on a dentrys dname.name Date: Wed, 19 Jun 2024 14:56:47 +0200 Message-ID: <20240619125616.142623775@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240619125606.345939659@linuxfoundation.org> References: <20240619125606.345939659@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: Stefan Berger commit be84f32bb2c981ca670922e047cdde1488b233de upstream. ->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: Greg Kroah-Hartman --- security/integrity/ima/ima_api.c | 16 ++++++++++++---- security/integrity/ima/ima_template_lib.c | 17 ++++++++++++++--- 2 files changed, 26 insertions(+), 7 deletions(-) --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -244,8 +244,8 @@ int ima_collect_measurement(struct integ 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 @@ out: 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 @@ out: */ 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 } 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; } --- 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(str 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(str } 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(str */ 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; } /*