#ifndef _NET_IP6_TUNNEL_H #define _NET_IP6_TUNNEL_H #include #include #include #include #include #include #define IP6TUNNEL_ERR_TIMEO (30*HZ) /* capable of sending packets */ #define IP6_TNL_F_CAP_XMIT 0x10000 /* capable of receiving packets */ #define IP6_TNL_F_CAP_RCV 0x20000 /* determine capability on a per-packet basis */ #define IP6_TNL_F_CAP_PER_PACKET 0x40000 struct __ip6_tnl_parm { char name[IFNAMSIZ]; /* name of tunnel device */ int link; /* ifindex of underlying L2 interface */ __u8 proto; /* tunnel protocol */ __u8 encap_limit; /* encapsulation limit for tunnel */ __u8 hop_limit; /* hop limit for tunnel */ bool collect_md; __be32 flowinfo; /* traffic class and flowlabel for tunnel */ __u32 flags; /* tunnel flags */ struct in6_addr laddr; /* local tunnel end-point address */ struct in6_addr raddr; /* remote tunnel end-point address */ __be16 i_flags; __be16 o_flags; __be32 i_key; __be32 o_key; }; /* IPv6 tunnel */ struct ip6_tnl { struct ip6_tnl __rcu *next; /* next tunnel in list */ struct net_device *dev; /* virtual device associated with tunnel */ struct net *net; /* netns for packet i/o */ struct __ip6_tnl_parm parms; /* tunnel configuration parameters */ struct flowi fl; /* flowi template for xmit */ struct dst_cache dst_cache; /* cached dst */ struct gro_cells gro_cells; int err_count; unsigned long err_time; /* These fields used only by GRE */ __u32 i_seqno; /* The last seen seqno */ __u32 o_seqno; /* The last output seqno */ int hlen; /* tun_hlen + encap_hlen */ int tun_hlen; /* Precalculated header length */ int encap_hlen; /* Encap header length (FOU,GUE) */ struct ip_tunnel_encap encap; int mlink; }; struct ip6_tnl_encap_ops { size_t (*encap_hlen)(struct ip_tunnel_encap *e); int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e, u8 *protocol, struct flowi6 *fl6); }; #ifdef CONFIG_INET extern const struct ip6_tnl_encap_ops __rcu * ip6tun_encaps[MAX_IPTUN_ENCAP_OPS]; int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops, unsigned int num); int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops, unsigned int num); int ip6_tnl_encap_setup(struct ip6_tnl *t, struct ip_tunnel_encap *ipencap); static inline int ip6_encap_hlen(struct ip_tunnel_encap *e) { const struct ip6_tnl_encap_ops *ops; int hlen = -EINVAL; if (e->type == TUNNEL_ENCAP_NONE) return 0; if (e->type >= MAX_IPTUN_ENCAP_OPS) return -EINVAL; rcu_read_lock(); ops = rcu_dereference(ip6tun_encaps[e->type]); if (likely(ops && ops->encap_hlen)) hlen = ops->encap_hlen(e); rcu_read_unlock(); return hlen; } static inline int ip6_tnl_encap(struct sk_buff *skb, struct ip6_tnl *t, u8 *protocol, struct flowi6 *fl6) { const struct ip6_tnl_encap_ops *ops; int ret = -EINVAL; if (t->encap.type == TUNNEL_ENCAP_NONE) return 0; if (t->encap.type >= MAX_IPTUN_ENCAP_OPS) return -EINVAL; rcu_read_lock(); ops = rcu_dereference(ip6tun_encaps[t->encap.type]); if (likely(ops && ops->build_header)) ret = ops->build_header(skb, &t->encap, protocol, fl6); rcu_read_unlock(); return ret; } /* Tunnel encapsulation limit destination sub-option */ struct ipv6_tlv_tnl_enc_lim { __u8 type; /* type-code for option */ __u8 length; /* option length */ __u8 encap_limit; /* tunnel encapsulation limit */ } __packed; int ip6_tnl_rcv_ctl(struct ip6_tnl *t, const struct in6_addr *laddr, const struct in6_addr *raddr); int ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb, const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst, bool log_ecn_error); int ip6_tnl_xmit_ctl(struct ip6_tnl *t, const struct in6_addr *laddr, const struct in6_addr *raddr); int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, struct flowi6 *fl6, int encap_limit, __u32 *pmtu, __u8 proto); __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw); __u32 ip6_tnl_get_cap(struct ip6_tnl *t, const struct in6_addr *laddr, const struct in6_addr *raddr); struct net *ip6_tnl_get_link_net(const struct net_device *dev); int ip6_tnl_get_iflink(const struct net_device *dev); int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu); static inline void ip6tunnel_xmit(struct sock *sk, struct sk_buff *skb, struct net_device *dev) { int pkt_len, err; memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); pkt_len = skb->len - skb_inner_network_offset(skb); err = ip6_local_out(dev_net(skb_dst(skb)->dev), sk, skb); if (unlikely(net_xmit_eval(err))) pkt_len = -1; iptunnel_xmit_stats(dev, pkt_len); } #endif #endif 0500 commit966d2b04e070bc040319aaebfec09e0144dc3341 (patch) tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /net/rds/tcp_recv.c parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'net/rds/tcp_recv.c')