From ec521c173fe9b56343808dfde63e3d75b223da07 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Fri, 2 Mar 2012 10:43:48 -0800 Subject: regset: Prevent null pointer reference on readonly regsets commit c8e252586f8d5de906385d8cf6385fee289a825e upstream. The regset common infrastructure assumed that regsets would always have .get and .set methods, but not necessarily .active methods. Unfortunately people have since written regsets without .set methods. Rather than putting in stub functions everywhere, handle regsets with null .get or .set methods explicitly. Signed-off-by: H. Peter Anvin Reviewed-by: Oleg Nesterov Acked-by: Roland McGrath Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/regset.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include') diff --git a/include/linux/regset.h b/include/linux/regset.h index 8abee65..5150fd1 100644 --- a/include/linux/regset.h +++ b/include/linux/regset.h @@ -335,6 +335,9 @@ static inline int copy_regset_to_user(struct task_struct *target, { const struct user_regset *regset = &view->regsets[setno]; + if (!regset->get) + return -EOPNOTSUPP; + if (!access_ok(VERIFY_WRITE, data, size)) return -EIO; @@ -358,6 +361,9 @@ static inline int copy_regset_from_user(struct task_struct *target, { const struct user_regset *regset = &view->regsets[setno]; + if (!regset->set) + return -EOPNOTSUPP; + if (!access_ok(VERIFY_READ, data, size)) return -EIO; -- cgit v1.1