Commit bc6de804 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

debugfs: be more robust at handling improper input in debugfs_lookup() 



debugfs_lookup() doesn't like it if it is passed an illegal name
pointer, or if the filesystem isn't even initialized yet.  If either of
these happen, it will crash the system, so fix it up by properly testing
for valid input and that we are up and running before trying to find a
file in the filesystem.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: stable <stable@vger.kernel.org>
Reported-by: default avatarMichael Walle <michael@walle.cc>
Tested-by: default avatarMichael Walle <michael@walle.cc>
Tested-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210218100818.3622317-1-gregkh@linuxfoundation.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 471b12c4

fs/debugfs/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -297,7 +297,7 @@ struct dentry *debugfs_lookup(const char *name, struct dentry *parent) 
{

	struct dentry *dentry;



	if (IS_ERR(parent))

	if (!debugfs_initialized() || IS_ERR_OR_NULL(name) || IS_ERR(parent))

		return NULL;



	if (!parent)