Messages in this thread Patch in this message |  | | Date | Wed, 29 Sep 2021 11:12:22 -0700 | | From | Kees Cook <> | | Subject | Re: [PATCH 3/5] kernel/sched: improve the BUILD_BUG_ON() in get_task_comm() |
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On Wed, Sep 29, 2021 at 11:50:34AM +0000, Yafang Shao wrote: > What we really want to guarantee is that the buf size can't be less than > TASK_COMM_LEN. While the size be greater than TASK_COMM_LEN is > acceptable.
This makes sense when task_struct::comm is a pointer. (But I think it's not a good idea to do that.)
-Kees
> > Signed-off-by: Yafang Shao <laoar.shao@gmail.com> > --- > include/linux/sched.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/sched.h b/include/linux/sched.h > index b387b5943db4..959eaef248fc 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -1931,7 +1931,7 @@ static inline void set_task_comm(struct task_struct *tsk, const char *from) > > extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk); > #define get_task_comm(buf, tsk) ({ \ > - BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \ > + BUILD_BUG_ON(sizeof(buf) < TASK_COMM_LEN); \ > __get_task_comm(buf, sizeof(buf), tsk); \ > }) > > -- > 2.17.1 >
-- Kees Cook
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