6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit 386520e0ecc01004d3a29c70c5a77d4bbf8a8420 ]
Similarly to RTNL_FLAG_DOIT_UNLOCKED, this new flag
allows dump operations registered via rtnl_register()
or rtnl_register_module() to opt-out from RTNL protection.
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reviewed-by: Donald Hunter <donald.hunter@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Stable-dep-of: 5be2062e3080 ("mpls: Handle error of rtnl_register_module().")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
include/linux/netlink.h | 2 ++
include/net/rtnetlink.h | 1 +
net/core/rtnetlink.c | 2 ++
net/netlink/af_netlink.c | 3 +++
4 files changed, 8 insertions(+)
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 75d7de34c9087..e8d713a37d176 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -289,6 +289,7 @@ struct netlink_callback {
u16 answer_flags;
u32 min_dump_alloc;
unsigned int prev_seq, seq;
+ int flags;
bool strict_check;
union {
u8 ctx[48];
@@ -321,6 +322,7 @@ struct netlink_dump_control {
void *data;
struct module *module;
u32 min_dump_alloc;
+ int flags;
};
int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index 0bd400be3f8d9..c1fa6fee0acfa 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -12,6 +12,7 @@ typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *);
enum rtnl_link_flags {
RTNL_FLAG_DOIT_UNLOCKED = BIT(0),
RTNL_FLAG_BULK_DEL_SUPPORTED = BIT(1),
+ RTNL_FLAG_DUMP_UNLOCKED = BIT(2),
};
enum rtnl_kinds {
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index ffa1334cddf44..c76c54879fddd 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -6405,6 +6405,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
}
owner = link->owner;
dumpit = link->dumpit;
+ flags = link->flags;
if (type == RTM_GETLINK - RTM_BASE)
min_dump_alloc = rtnl_calcit(skb, nlh);
@@ -6422,6 +6423,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
.dump = dumpit,
.min_dump_alloc = min_dump_alloc,
.module = owner,
+ .flags = flags,
};
err = netlink_dump_start(rtnl, skb, nlh, &c);
/* netlink_dump_start() will keep a reference on
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index e40376997f393..8e7d5f17c58b8 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2263,6 +2263,8 @@ static int netlink_dump(struct sock *sk, bool lock_taken)
cb->extack = &extack;
+ if (cb->flags & RTNL_FLAG_DUMP_UNLOCKED)
+ extra_mutex = NULL;
if (extra_mutex)
mutex_lock(extra_mutex);
nlk->dump_done_errno = cb->dump(skb, cb);
@@ -2357,6 +2359,7 @@ int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
cb->data = control->data;
cb->module = control->module;
cb->min_dump_alloc = control->min_dump_alloc;
+ cb->flags = control->flags;
cb->skb = skb;
cb->strict_check = nlk_test_bit(STRICT_CHK, NETLINK_CB(skb).sk);
--
2.43.0
