Nikolay Aleksandrov
2022-Apr-13 10:51 UTC
[Bridge] [PATCH net-next v4 05/12] net: rtnetlink: add bulk delete support flag
Add a new rtnl flag (RTNL_FLAG_BULK_DEL_SUPPORTED) which is used to
verify that the delete operation allows bulk object deletion. Also emit
a warning if anyone tries to set it for non-delete kind.
Suggested-by: David Ahern <dsahern at kernel.org>
Signed-off-by: Nikolay Aleksandrov <razor at blackwall.org>
---
v4: new patch
include/net/rtnetlink.h | 3 ++-
net/core/rtnetlink.c | 8 ++++++++
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index 0bf622409aaa..bf8bb3357825 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -10,7 +10,8 @@ typedef int (*rtnl_doit_func)(struct sk_buff *, struct
nlmsghdr *,
typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *);
enum rtnl_link_flags {
- RTNL_FLAG_DOIT_UNLOCKED = BIT(0),
+ RTNL_FLAG_DOIT_UNLOCKED = BIT(0),
+ RTNL_FLAG_BULK_DEL_SUPPORTED = BIT(1),
};
enum rtnl_kinds {
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index beda4a7da062..63c7df52a667 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -249,6 +249,8 @@ static int rtnl_register_internal(struct module *owner,
if (dumpit)
link->dumpit = dumpit;
+ WARN_ON(rtnl_msgtype_kind(msgtype) != RTNL_KIND_DEL &&
+ (flags & RTNL_FLAG_BULK_DEL_SUPPORTED));
link->flags |= flags;
/* publish protocol:msgtype */
@@ -6009,6 +6011,12 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct
nlmsghdr *nlh,
}
flags = link->flags;
+ if (kind == RTNL_KIND_DEL && (nlh->nlmsg_flags & NLM_F_BULK)
&&
+ !(flags & RTNL_FLAG_BULK_DEL_SUPPORTED)) {
+ NL_SET_ERR_MSG(extack, "Bulk delete is not supported");
+ goto err_unlock;
+ }
+
if (flags & RTNL_FLAG_DOIT_UNLOCKED) {
doit = link->doit;
rcu_read_unlock();
--
2.35.1
Ido Schimmel
2022-Apr-13 12:06 UTC
[Bridge] [PATCH net-next v4 05/12] net: rtnetlink: add bulk delete support flag
On Wed, Apr 13, 2022 at 01:51:55PM +0300, Nikolay Aleksandrov wrote:> Add a new rtnl flag (RTNL_FLAG_BULK_DEL_SUPPORTED) which is used to > verify that the delete operation allows bulk object deletion. Also emit > a warning if anyone tries to set it for non-delete kind. > > Suggested-by: David Ahern <dsahern at kernel.org> > Signed-off-by: Nikolay Aleksandrov <razor at blackwall.org> > --- > v4: new patch > > include/net/rtnetlink.h | 3 ++- > net/core/rtnetlink.c | 8 ++++++++ > 2 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h > index 0bf622409aaa..bf8bb3357825 100644 > --- a/include/net/rtnetlink.h > +++ b/include/net/rtnetlink.h > @@ -10,7 +10,8 @@ typedef int (*rtnl_doit_func)(struct sk_buff *, struct nlmsghdr *, > typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *); > > enum rtnl_link_flags { > - RTNL_FLAG_DOIT_UNLOCKED = BIT(0), > + RTNL_FLAG_DOIT_UNLOCKED = BIT(0), > + RTNL_FLAG_BULK_DEL_SUPPORTED = BIT(1), > }; > > enum rtnl_kinds { > diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c > index beda4a7da062..63c7df52a667 100644 > --- a/net/core/rtnetlink.c > +++ b/net/core/rtnetlink.c > @@ -249,6 +249,8 @@ static int rtnl_register_internal(struct module *owner, > if (dumpit) > link->dumpit = dumpit; > > + WARN_ON(rtnl_msgtype_kind(msgtype) != RTNL_KIND_DEL && > + (flags & RTNL_FLAG_BULK_DEL_SUPPORTED)); > link->flags |= flags; > > /* publish protocol:msgtype */ > @@ -6009,6 +6011,12 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, > } > > flags = link->flags; > + if (kind == RTNL_KIND_DEL && (nlh->nlmsg_flags & NLM_F_BULK) && > + !(flags & RTNL_FLAG_BULK_DEL_SUPPORTED)) { > + NL_SET_ERR_MSG(extack, "Bulk delete is not supported"); > + goto err_unlock;If a buggy user space application is sending messages with NLM_F_BULK set (unintentionally), will it break on newer kernel? I couldn't find where the kernel was validating that reserved flags are not used (I suspect it doesn't). Assuming the above is correct and of interest, maybe just emit a warning via extack and drop the goto? Alternatively, we can see if anyone complains which might never happen> + } > + > if (flags & RTNL_FLAG_DOIT_UNLOCKED) { > doit = link->doit; > rcu_read_unlock(); > -- > 2.35.1 >