From ac40916a3f7243efbe6e129ebf495b5c33a3adfe Mon Sep 17 00:00:00 2001 From: Li RongQing Date: Wed, 15 Nov 2023 20:01:08 +0800 Subject: [PATCH] rtnetlink: introduce nlmsg_new_large and use it in rtnl_getlink if a PF has 256 or more VFs, ip link command will allocate an order 3 memory or more, and maybe trigger OOM due to memory fragment, the VFs needed memory size is computed in rtnl_vfinfo_size. so introduce nlmsg_new_large which calls netlink_alloc_large_skb in which vmalloc is used for large memory, to avoid the failure of allocating memory ip invoked oom-killer: gfp_mask=0xc2cc0(GFP_KERNEL|__GFP_NOWARN|\ __GFP_COMP|__GFP_NOMEMALLOC), order=3, oom_score_adj=0 CPU: 74 PID: 204414 Comm: ip Kdump: loaded Tainted: P OE Call Trace: dump_stack+0x57/0x6a dump_header+0x4a/0x210 oom_kill_process+0xe4/0x140 out_of_memory+0x3e8/0x790 __alloc_pages_slowpath.constprop.116+0x953/0xc50 __alloc_pages_nodemask+0x2af/0x310 kmalloc_large_node+0x38/0xf0 __kmalloc_node_track_caller+0x417/0x4d0 __kmalloc_reserve.isra.61+0x2e/0x80 __alloc_skb+0x82/0x1c0 rtnl_getlink+0x24f/0x370 rtnetlink_rcv_msg+0x12c/0x350 netlink_rcv_skb+0x50/0x100 netlink_unicast+0x1b2/0x280 netlink_sendmsg+0x355/0x4a0 sock_sendmsg+0x5b/0x60 ____sys_sendmsg+0x1ea/0x250 ___sys_sendmsg+0x88/0xd0 __sys_sendmsg+0x5e/0xa0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f95a65a5b70 Cc: Yunsheng Lin Signed-off-by: Li RongQing Link: https://lore.kernel.org/r/20231115120108.3711-1-lirongqing@baidu.com Signed-off-by: Jakub Kicinski --- include/linux/netlink.h | 1 + include/net/netlink.h | 14 ++++++++++++++ net/core/rtnetlink.c | 2 +- net/netlink/af_netlink.c | 3 +-- 4 files changed, 17 insertions(+), 3 deletions(-) diff --git a/include/linux/netlink.h b/include/linux/netlink.h index 75d7de34c908..abe91ed6b9aa 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -351,5 +351,6 @@ bool netlink_ns_capable(const struct sk_buff *skb, struct user_namespace *ns, int cap); bool netlink_capable(const struct sk_buff *skb, int cap); bool netlink_net_capable(const struct sk_buff *skb, int cap); +struct sk_buff *netlink_alloc_large_skb(unsigned int size, int broadcast); #endif /* __LINUX_NETLINK_H */ diff --git a/include/net/netlink.h b/include/net/netlink.h index 83bdf787aeee..167b91348e57 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -1010,6 +1010,20 @@ static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags) return alloc_skb(nlmsg_total_size(payload), flags); } +/** + * nlmsg_new_large - Allocate a new netlink message with non-contiguous + * physical memory + * @payload: size of the message payload + * + * The allocated skb is unable to have frag page for shinfo->frags*, + * as the NULL setting for skb->head in netlink_skb_destructor() will + * bypass most of the handling in skb_release_data() + */ +static inline struct sk_buff *nlmsg_new_large(size_t payload) +{ + return netlink_alloc_large_skb(nlmsg_total_size(payload), 0); +} + /** * nlmsg_end - Finalize a netlink message * @skb: socket buffer the message is stored in diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index e8431c6c8490..592164c2a540 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3849,7 +3849,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh, goto out; err = -ENOBUFS; - nskb = nlmsg_new(if_nlmsg_size(dev, ext_filter_mask), GFP_KERNEL); + nskb = nlmsg_new_large(if_nlmsg_size(dev, ext_filter_mask)); if (nskb == NULL) goto out; diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index eb086b06d60d..177126fb0484 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -1204,8 +1204,7 @@ struct sock *netlink_getsockbyfilp(struct file *filp) return sock; } -static struct sk_buff *netlink_alloc_large_skb(unsigned int size, - int broadcast) +struct sk_buff *netlink_alloc_large_skb(unsigned int size, int broadcast) { struct sk_buff *skb; void *data; -- 2.20.1