linux-kernel - [PATCH 5.10 129/236] debugfs: Return error during {full/open}_proxy

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210913131104.753295134@linuxfoundation.org>
Date:   Mon, 13 Sep 2021 15:13:54 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Taehee Yoo <ap420073@...il.com>,
        Mário Lopes <ml@...onwunderlich.de>,
        Sven Eckelmann <sven@...fation.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.10 129/236] debugfs: Return error during {full/open}_proxy_open() on rmmod

From: Sven Eckelmann <sven@...fation.org>

[ Upstream commit 112cedc8e600b668688eb809bf11817adec58ddc ]

If a kernel module gets unloaded then it printed report about a leak before
commit 275678e7a9be ("debugfs: Check module state before warning in
{full/open}_proxy_open()"). An additional check was added in this commit to
avoid this printing. But it was forgotten that the function must return an
error in this case because it was not actually opened.

As result, the systems started to crash or to hang when a module was
unloaded while something was trying to open a file.

Fixes: 275678e7a9be ("debugfs: Check module state before warning in {full/open}_proxy_open()")
Cc: Taehee Yoo <ap420073@...il.com>
Reported-by: Mário Lopes <ml@...onwunderlich.de>
Signed-off-by: Sven Eckelmann <sven@...fation.org>
Link: https://lore.kernel.org/r/20210802162444.7848-1-sven@narfation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 fs/debugfs/file.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 686e0ad28788..3aa5eb9ce498 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -179,8 +179,10 @@ static int open_proxy_open(struct inode *inode, struct file *filp)
 	if (!fops_get(real_fops)) {
 #ifdef CONFIG_MODULES
 		if (real_fops->owner &&
-		    real_fops->owner->state == MODULE_STATE_GOING)
+		    real_fops->owner->state == MODULE_STATE_GOING) {
+			r = -ENXIO;
 			goto out;
+		}
 #endif
 
 		/* Huh? Module did not clean up after itself at exit? */
@@ -314,8 +316,10 @@ static int full_proxy_open(struct inode *inode, struct file *filp)
 	if (!fops_get(real_fops)) {
 #ifdef CONFIG_MODULES
 		if (real_fops->owner &&
-		    real_fops->owner->state == MODULE_STATE_GOING)
+		    real_fops->owner->state == MODULE_STATE_GOING) {
+			r = -ENXIO;
 			goto out;
+		}
 #endif
 
 		/* Huh? Module did not cleanup after itself at exit? */
-- 
2.30.2