From: Eric Dumazet <edumazet@google.com> stable inclusion from stable-v6.6.57 commit ba5366b87c0dc3b15463495598737e28015559cd category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IB6YDK Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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@google.com> Reviewed-by: Donald Hunter <donald.hunter@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: 5be2062e3080 ("mpls: Handle error of rtnl_register_module().") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Wang Liang <wangliang74@huawei.com> --- 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 4111d53f4656..4b4b942d4613 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -294,6 +294,7 @@ struct netlink_callback { u16 answer_flags; u32 min_dump_alloc; unsigned int prev_seq, seq; + int flags; bool strict_check; union { u8 ctx[48]; @@ -326,6 +327,7 @@ 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 318b3168e77b..365e36a19c49 100644 --- a/include/net/rtnetlink.h +++ b/include/net/rtnetlink.h @@ -13,6 +13,7 @@ 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 71775e1e9c39..4acde7067519 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 5ea5cfdf4c06..4aa2cbe9d6fa 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2249,6 +2249,8 @@ 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); @@ -2343,6 +2345,7 @@ 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); -- 2.34.1