From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Szyprowski Subject: [PATCH] tracefs: Fix NULL pointer dereference when no lockdown is used Date: Wed, 14 Aug 2019 08:12:37 +0200 Message-ID: <20190814061237.17406-1-m.szyprowski@samsung.com> References: <3028ed35-3b6d-459f-f3c8-103c5636fe95@samsung.com> Content-Type: text/plain; charset="utf-8" Return-path: In-Reply-To: <3028ed35-3b6d-459f-f3c8-103c5636fe95@samsung.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: Marek Szyprowski , Matthew Garrett , Steven Rostedt , James Morris , Krzysztof Kozlowski , Bartlomiej Zolnierkiewicz , linux-security-module@vger.kernel.org, linux-api@vger.kernel.org, Matthew Garrett List-Id: linux-api@vger.kernel.org Commit 757ff7244358 ("tracefs: Restrict tracefs when the kernel is locked down") added infrastructure for restricting tracefs access when lockdown is enabled. It however broke tracefs operation when no lockdown is used. Fix this issue by adding missing check for a NULL ->open() callback. Fixes: 757ff7244358 ("tracefs: Restrict tracefs when the kernel is locked down") Reported-by: Krzysztof Kozlowski Signed-off-by: Marek Szyprowski --- fs/tracefs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c index 12a325fb4cbd..8efff7603032 100644 --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -43,7 +43,7 @@ static int default_open_file(struct inode *inode, struct file *filp) return ret; real_fops = dentry->d_fsdata; - return real_fops->open(inode, filp); + return real_fops->open ? real_fops->open(inode, filp) : 0; } static ssize_t default_read_file(struct file *file, char __user *buf, -- 2.17.1