From ba51b6be38c122f7dab40965b4397aaf6188a464 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Mon, 24 Aug 2015 15:17:17 -0600 Subject: [PATCH] net: Fix RCU splat in af_key Hit the following splat testing VRF change for ipsec: [ 113.475692] =============================== [ 113.476194] [ INFO: suspicious RCU usage. ] [ 113.476667] 4.2.0-rc6-1+deb7u2+clUNRELEASED #3.2.65-1+deb7u2+clUNRELEASED Not tainted [ 113.477545] ------------------------------- [ 113.478013] /work/monster-14/dsa/kernel.git/include/linux/rcupdate.h:568 Illegal context switch in RCU read-side critical section! [ 113.479288] [ 113.479288] other info that might help us debug this: [ 113.479288] [ 113.480207] [ 113.480207] rcu_scheduler_active = 1, debug_locks = 1 [ 113.480931] 2 locks held by setkey/6829: [ 113.481371] #0: (&net->xfrm.xfrm_cfg_mutex){+.+.+.}, at: [] pfkey_sendmsg+0xfb/0x213 [ 113.482509] #1: (rcu_read_lock){......}, at: [] rcu_read_lock+0x0/0x6e [ 113.483509] [ 113.483509] stack backtrace: [ 113.484041] CPU: 0 PID: 6829 Comm: setkey Not tainted 4.2.0-rc6-1+deb7u2+clUNRELEASED #3.2.65-1+deb7u2+clUNRELEASED [ 113.485422] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014 [ 113.486845] 0000000000000001 ffff88001d4c7a98 ffffffff81518af2 ffffffff81086962 [ 113.487732] ffff88001d538480 ffff88001d4c7ac8 ffffffff8107ae75 ffffffff8180a154 [ 113.488628] 0000000000000b30 0000000000000000 00000000000000d0 ffff88001d4c7ad8 [ 113.489525] Call Trace: [ 113.489813] [] dump_stack+0x4c/0x65 [ 113.490389] [] ? console_unlock+0x3d6/0x405 [ 113.491039] [] lockdep_rcu_suspicious+0xfa/0x103 [ 113.491735] [] rcu_preempt_sleep_check+0x45/0x47 [ 113.492442] [] ___might_sleep+0x19/0x1c8 [ 113.493077] [] __might_sleep+0x6c/0x82 [ 113.493681] [] cache_alloc_debugcheck_before.isra.50+0x1d/0x24 [ 113.494508] [] kmem_cache_alloc+0x31/0x18f [ 113.495149] [] skb_clone+0x64/0x80 [ 113.495712] [] pfkey_broadcast_one+0x3d/0xff [ 113.496380] [] pfkey_broadcast+0xb5/0x11e [ 113.497024] [] pfkey_register+0x191/0x1b1 [ 113.497653] [] pfkey_process+0x162/0x17e [ 113.498274] [] pfkey_sendmsg+0x109/0x213 In pfkey_sendmsg the net mutex is taken and then pfkey_broadcast takes the RCU lock. Since pfkey_broadcast takes the RCU lock the allocation argument is pointless since GFP_ATOMIC must be used between the rcu_read_{,un}lock. The one call outside of rcu can be done with GFP_KERNEL. Fixes: 7f6b9dbd5afbd ("af_key: locking change") Signed-off-by: David Ahern Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/key/af_key.c | 46 +++++++++++++++++++++++----------------------- 1 file changed, 23 insertions(+), 23 deletions(-) diff --git a/net/key/af_key.c b/net/key/af_key.c index b397f0aa9005..83a70688784b 100644 --- a/net/key/af_key.c +++ b/net/key/af_key.c @@ -219,7 +219,7 @@ static int pfkey_broadcast_one(struct sk_buff *skb, struct sk_buff **skb2, #define BROADCAST_ONE 1 #define BROADCAST_REGISTERED 2 #define BROADCAST_PROMISC_ONLY 4 -static int pfkey_broadcast(struct sk_buff *skb, gfp_t allocation, +static int pfkey_broadcast(struct sk_buff *skb, int broadcast_flags, struct sock *one_sk, struct net *net) { @@ -244,7 +244,7 @@ static int pfkey_broadcast(struct sk_buff *skb, gfp_t allocation, * socket. */ if (pfk->promisc) - pfkey_broadcast_one(skb, &skb2, allocation, sk); + pfkey_broadcast_one(skb, &skb2, GFP_ATOMIC, sk); /* the exact target will be processed later */ if (sk == one_sk) @@ -259,7 +259,7 @@ static int pfkey_broadcast(struct sk_buff *skb, gfp_t allocation, continue; } - err2 = pfkey_broadcast_one(skb, &skb2, allocation, sk); + err2 = pfkey_broadcast_one(skb, &skb2, GFP_ATOMIC, sk); /* Error is cleare after succecful sending to at least one * registered KM */ @@ -269,7 +269,7 @@ static int pfkey_broadcast(struct sk_buff *skb, gfp_t allocation, rcu_read_unlock(); if (one_sk != NULL) - err = pfkey_broadcast_one(skb, &skb2, allocation, one_sk); + err = pfkey_broadcast_one(skb, &skb2, GFP_KERNEL, one_sk); kfree_skb(skb2); kfree_skb(skb); @@ -292,7 +292,7 @@ static int pfkey_do_dump(struct pfkey_sock *pfk) hdr = (struct sadb_msg *) pfk->dump.skb->data; hdr->sadb_msg_seq = 0; hdr->sadb_msg_errno = rc; - pfkey_broadcast(pfk->dump.skb, GFP_ATOMIC, BROADCAST_ONE, + pfkey_broadcast(pfk->dump.skb, BROADCAST_ONE, &pfk->sk, sock_net(&pfk->sk)); pfk->dump.skb = NULL; } @@ -333,7 +333,7 @@ static int pfkey_error(const struct sadb_msg *orig, int err, struct sock *sk) hdr->sadb_msg_len = (sizeof(struct sadb_msg) / sizeof(uint64_t)); - pfkey_broadcast(skb, GFP_KERNEL, BROADCAST_ONE, sk, sock_net(sk)); + pfkey_broadcast(skb, BROADCAST_ONE, sk, sock_net(sk)); return 0; } @@ -1365,7 +1365,7 @@ static int pfkey_getspi(struct sock *sk, struct sk_buff *skb, const struct sadb_ xfrm_state_put(x); - pfkey_broadcast(resp_skb, GFP_KERNEL, BROADCAST_ONE, sk, net); + pfkey_broadcast(resp_skb, BROADCAST_ONE, sk, net); return 0; } @@ -1452,7 +1452,7 @@ static int key_notify_sa(struct xfrm_state *x, const struct km_event *c) hdr->sadb_msg_seq = c->seq; hdr->sadb_msg_pid = c->portid; - pfkey_broadcast(skb, GFP_ATOMIC, BROADCAST_ALL, NULL, xs_net(x)); + pfkey_broadcast(skb, BROADCAST_ALL, NULL, xs_net(x)); return 0; } @@ -1565,7 +1565,7 @@ static int pfkey_get(struct sock *sk, struct sk_buff *skb, const struct sadb_msg out_hdr->sadb_msg_reserved = 0; out_hdr->sadb_msg_seq = hdr->sadb_msg_seq; out_hdr->sadb_msg_pid = hdr->sadb_msg_pid; - pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_ONE, sk, sock_net(sk)); + pfkey_broadcast(out_skb, BROADCAST_ONE, sk, sock_net(sk)); return 0; } @@ -1670,7 +1670,7 @@ static int pfkey_register(struct sock *sk, struct sk_buff *skb, const struct sad return -ENOBUFS; } - pfkey_broadcast(supp_skb, GFP_KERNEL, BROADCAST_REGISTERED, sk, sock_net(sk)); + pfkey_broadcast(supp_skb, BROADCAST_REGISTERED, sk, sock_net(sk)); return 0; } @@ -1689,7 +1689,7 @@ static int unicast_flush_resp(struct sock *sk, const struct sadb_msg *ihdr) hdr->sadb_msg_errno = (uint8_t) 0; hdr->sadb_msg_len = (sizeof(struct sadb_msg) / sizeof(uint64_t)); - return pfkey_broadcast(skb, GFP_ATOMIC, BROADCAST_ONE, sk, sock_net(sk)); + return pfkey_broadcast(skb, BROADCAST_ONE, sk, sock_net(sk)); } static int key_notify_sa_flush(const struct km_event *c) @@ -1710,7 +1710,7 @@ static int key_notify_sa_flush(const struct km_event *c) hdr->sadb_msg_len = (sizeof(struct sadb_msg) / sizeof(uint64_t)); hdr->sadb_msg_reserved = 0; - pfkey_broadcast(skb, GFP_ATOMIC, BROADCAST_ALL, NULL, c->net); + pfkey_broadcast(skb, BROADCAST_ALL, NULL, c->net); return 0; } @@ -1767,7 +1767,7 @@ static int dump_sa(struct xfrm_state *x, int count, void *ptr) out_hdr->sadb_msg_pid = pfk->dump.msg_portid; if (pfk->dump.skb) - pfkey_broadcast(pfk->dump.skb, GFP_ATOMIC, BROADCAST_ONE, + pfkey_broadcast(pfk->dump.skb, BROADCAST_ONE, &pfk->sk, sock_net(&pfk->sk)); pfk->dump.skb = out_skb; @@ -1847,7 +1847,7 @@ static int pfkey_promisc(struct sock *sk, struct sk_buff *skb, const struct sadb new_hdr->sadb_msg_errno = 0; } - pfkey_broadcast(skb, GFP_KERNEL, BROADCAST_ALL, NULL, sock_net(sk)); + pfkey_broadcast(skb, BROADCAST_ALL, NULL, sock_net(sk)); return 0; } @@ -2181,7 +2181,7 @@ static int key_notify_policy(struct xfrm_policy *xp, int dir, const struct km_ev out_hdr->sadb_msg_errno = 0; out_hdr->sadb_msg_seq = c->seq; out_hdr->sadb_msg_pid = c->portid; - pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_ALL, NULL, xp_net(xp)); + pfkey_broadcast(out_skb, BROADCAST_ALL, NULL, xp_net(xp)); return 0; } @@ -2401,7 +2401,7 @@ static int key_pol_get_resp(struct sock *sk, struct xfrm_policy *xp, const struc out_hdr->sadb_msg_errno = 0; out_hdr->sadb_msg_seq = hdr->sadb_msg_seq; out_hdr->sadb_msg_pid = hdr->sadb_msg_pid; - pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_ONE, sk, xp_net(xp)); + pfkey_broadcast(out_skb, BROADCAST_ONE, sk, xp_net(xp)); err = 0; out: @@ -2655,7 +2655,7 @@ static int dump_sp(struct xfrm_policy *xp, int dir, int count, void *ptr) out_hdr->sadb_msg_pid = pfk->dump.msg_portid; if (pfk->dump.skb) - pfkey_broadcast(pfk->dump.skb, GFP_ATOMIC, BROADCAST_ONE, + pfkey_broadcast(pfk->dump.skb, BROADCAST_ONE, &pfk->sk, sock_net(&pfk->sk)); pfk->dump.skb = out_skb; @@ -2708,7 +2708,7 @@ static int key_notify_policy_flush(const struct km_event *c) hdr->sadb_msg_satype = SADB_SATYPE_UNSPEC; hdr->sadb_msg_len = (sizeof(struct sadb_msg) / sizeof(uint64_t)); hdr->sadb_msg_reserved = 0; - pfkey_broadcast(skb_out, GFP_ATOMIC, BROADCAST_ALL, NULL, c->net); + pfkey_broadcast(skb_out, BROADCAST_ALL, NULL, c->net); return 0; } @@ -2770,7 +2770,7 @@ static int pfkey_process(struct sock *sk, struct sk_buff *skb, const struct sadb void *ext_hdrs[SADB_EXT_MAX]; int err; - pfkey_broadcast(skb_clone(skb, GFP_KERNEL), GFP_KERNEL, + pfkey_broadcast(skb_clone(skb, GFP_KERNEL), BROADCAST_PROMISC_ONLY, NULL, sock_net(sk)); memset(ext_hdrs, 0, sizeof(ext_hdrs)); @@ -2992,7 +2992,7 @@ static int key_notify_sa_expire(struct xfrm_state *x, const struct km_event *c) out_hdr->sadb_msg_seq = 0; out_hdr->sadb_msg_pid = 0; - pfkey_broadcast(out_skb, GFP_ATOMIC, BROADCAST_REGISTERED, NULL, xs_net(x)); + pfkey_broadcast(out_skb, BROADCAST_REGISTERED, NULL, xs_net(x)); return 0; } @@ -3182,7 +3182,7 @@ static int pfkey_send_acquire(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_ctx->ctx_len); } - return pfkey_broadcast(skb, GFP_ATOMIC, BROADCAST_REGISTERED, NULL, xs_net(x)); + return pfkey_broadcast(skb, BROADCAST_REGISTERED, NULL, xs_net(x)); } static struct xfrm_policy *pfkey_compile_policy(struct sock *sk, int opt, @@ -3380,7 +3380,7 @@ static int pfkey_send_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, n_port->sadb_x_nat_t_port_port = sport; n_port->sadb_x_nat_t_port_reserved = 0; - return pfkey_broadcast(skb, GFP_ATOMIC, BROADCAST_REGISTERED, NULL, xs_net(x)); + return pfkey_broadcast(skb, BROADCAST_REGISTERED, NULL, xs_net(x)); } #ifdef CONFIG_NET_KEY_MIGRATE @@ -3572,7 +3572,7 @@ static int pfkey_send_migrate(const struct xfrm_selector *sel, u8 dir, u8 type, } /* broadcast migrate message to sockets */ - pfkey_broadcast(skb, GFP_ATOMIC, BROADCAST_ALL, NULL, &init_net); + pfkey_broadcast(skb, BROADCAST_ALL, NULL, &init_net); return 0; -- 2.20.1