| Message ID | 20180227233156.29826-1-danilokrummrich@dk-develop.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Feb 27, 2018 at 3:31 PM, Danilo Krummrich <danilokrummrich@dk-develop.de> 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 <danilokrummrich@dk-develop.de> Acked-by: Kees Cook <keescook@chromium.org> > --- > 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 >
On Wed, Feb 28, 2018 at 12:31:55AM +0100, Danilo Krummrich 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 <danilokrummrich@dk-develop.de> > --- > v2: removed empty line between between sysctl_head_grab and IS_ERR Please add a respective tag: Fixes: 0e47c99d7fe25 ("sysctl: Replace root_list with links between sysctl_table_sets") And mention this has been present since v3.4. May be worth sending to stable as well, so peg stable as well. Luis > --- > 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 > >
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 */
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 <danilokrummrich@dk-develop.de> --- v2: removed empty line between between sysctl_head_grab and IS_ERR --- fs/proc/proc_sysctl.c | 3 +++ 1 file changed, 3 insertions(+)