On Tue, Feb 27, 2018 at 3:31 PM, Danilo Krummrich <[email protected]> wrote: > proc_sys_link_fill_cache() does not take currently unregistering > sysctl tables into account, which might result into a page fault in > sysctl_follow_link() - add a check to fix it. > > Signed-off-by: Danilo Krummrich <[email protected]>
Acked-by: Kees Cook <[email protected]> > --- > v2: removed empty line between between sysctl_head_grab and IS_ERR Thanks! -Kees > --- > fs/proc/proc_sysctl.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c > index c5cbbdff3c3d..82ac5f682b73 100644 > --- a/fs/proc/proc_sysctl.c > +++ b/fs/proc/proc_sysctl.c > @@ -707,7 +707,10 @@ static bool proc_sys_link_fill_cache(struct file *file, > struct ctl_table *table) > { > bool ret = true; > + > head = sysctl_head_grab(head); > + if (IS_ERR(head)) > + return false; > > if (S_ISLNK(table->mode)) { > /* It is not an error if we can not follow the link ignore it > */ > -- > 2.14.1 > -- Kees Cook Pixel Security
