diff mbox series

tracefs: Fix potential null dereference in default_file_open()

Message ID 20190812002833.2zij7tfsqtpvqu3a@decadent.org.uk
State New
Headers show
Series tracefs: Fix potential null dereference in default_file_open() | expand

Commit Message

Ben Hutchings Aug. 12, 2019, 12:28 a.m. UTC
The "open" operation in struct file_operations is optional, and
ftrace_event_id_fops does not set it.  In default_file_open(), after
all other checks have passed, return 0 if the underlying struct
file_operations does not implement open.

Fixes: 757ff7244358 ("tracefs: Restrict tracefs when the kernel is …")
References: https://bugs.debian.org/934304
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
 fs/tracefs/inode.c | 2 ++
 1 file changed, 2 insertions(+)
diff mbox series


diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index 34da48036e08..761af8ce4015 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -42,6 +42,8 @@  static int default_open_file(struct inode *inode, struct file *filp)
 		return ret;
 	real_fops = dentry->d_fsdata;
+	if (!real_fops->open)
+		return 0;
 	return real_fops->open(inode, filp);