[NETLINK]: Don't BUG on undersized allocations
Currently netlink users BUG when the allocated skb for an event
notification is undersized. While this is certainly a kernel bug,
its not critical and crashing the kernel is too drastic, especially
when considering that these errors have appeared multiple times in
the past and it BUGs even if no listeners are present.
This patch replaces BUG by WARN_ON and changes the notification
functions to inform potential listeners of undersized allocations
using a unique error code (EMSGSIZE).
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index a913968..7d68b24 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -45,7 +45,7 @@
nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
hdr = nlmsg_data(nlh);
hdr->ifi_family = AF_BRIDGE;
@@ -72,7 +72,8 @@
return nlmsg_end(skb, nlh);
nla_put_failure:
- return nlmsg_cancel(skb, nlh);
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
}
/*
@@ -89,9 +90,12 @@
goto errout;
err = br_fill_ifinfo(skb, port, 0, 0, event, 0);
- /* failure implies BUG in br_nlmsg_size() */
- BUG_ON(err < 0);
-
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in br_nlmsg_size() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
err = rtnl_notify(skb, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
errout:
if (err < 0)
diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 1df6cd45..215f1bff 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -331,7 +331,7 @@
nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
if (nlh == NULL)
- return -1;
+ return -EMSGSIZE;
frh = nlmsg_data(nlh);
frh->table = rule->table;
@@ -359,7 +359,8 @@
return nlmsg_end(skb, nlh);
nla_put_failure:
- return nlmsg_cancel(skb, nlh);
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
}
int fib_rules_dump(struct sk_buff *skb, struct netlink_callback *cb, int family)
@@ -405,9 +406,12 @@
goto errout;
err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
- /* failure implies BUG in fib_rule_nlmsg_size() */
- BUG_ON(err < 0);
-
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
err = rtnl_notify(skb, pid, ops->nlgroup, nlh, GFP_KERNEL);
errout:
if (err < 0)
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index e7300b6..9e26f38 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1637,7 +1637,7 @@
nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
ndtmsg = nlmsg_data(nlh);
@@ -1706,7 +1706,8 @@
nla_put_failure:
read_unlock_bh(&tbl->lock);
- return nlmsg_cancel(skb, nlh);
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
}
static int neightbl_fill_param_info(struct sk_buff *skb,
@@ -1720,7 +1721,7 @@
nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndtmsg), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
ndtmsg = nlmsg_data(nlh);
@@ -1737,7 +1738,8 @@
return nlmsg_end(skb, nlh);
errout:
read_unlock_bh(&tbl->lock);
- return nlmsg_cancel(skb, nlh);
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
}
static inline struct neigh_parms *lookup_neigh_params(struct neigh_table *tbl,
@@ -1955,7 +1957,7 @@
nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
ndm = nlmsg_data(nlh);
ndm->ndm_family = neigh->ops->family;
@@ -1987,7 +1989,8 @@
return nlmsg_end(skb, nlh);
nla_put_failure:
- return nlmsg_cancel(skb, nlh);
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
}
@@ -2429,9 +2432,12 @@
goto errout;
err = neigh_fill_info(skb, n, 0, 0, type, flags);
- /* failure implies BUG in neigh_nlmsg_size() */
- BUG_ON(err < 0);
-
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in neigh_nlmsg_size() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
err = rtnl_notify(skb, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
errout:
if (err < 0)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index e76539a..9bf9ae0 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -320,7 +320,7 @@
nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ifm), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
ifm = nlmsg_data(nlh);
ifm->ifi_family = AF_UNSPEC;
@@ -384,7 +384,8 @@
return nlmsg_end(skb, nlh);
nla_put_failure:
- return nlmsg_cancel(skb, nlh);
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
}
static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
@@ -633,9 +634,12 @@
err = rtnl_fill_ifinfo(nskb, dev, iw, iw_buf_len, RTM_NEWLINK,
NETLINK_CB(skb).pid, nlh->nlmsg_seq, 0, 0);
- /* failure impilies BUG in if_nlmsg_size or wireless_rtnetlink_get */
- BUG_ON(err < 0);
-
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in if_nlmsg_size */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(nskb);
+ goto errout;
+ }
err = rtnl_unicast(nskb, NETLINK_CB(skb).pid);
errout:
kfree(iw_buf);
@@ -678,9 +682,12 @@
goto errout;
err = rtnl_fill_ifinfo(skb, dev, NULL, 0, type, 0, 0, change, 0);
- /* failure implies BUG in if_nlmsg_size() */
- BUG_ON(err < 0);
-
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in if_nlmsg_size() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
err = rtnl_notify(skb, 0, RTNLGRP_LINK, NULL, GFP_KERNEL);
errout:
if (err < 0)
diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index ed083ab..90b3dfd 100644
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -749,7 +749,7 @@
nlh = nlmsg_put(skb, pid, seq, event, sizeof(*ifm), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
ifm = nlmsg_data(nlh);
ifm->ifa_family = AF_DECnet;
@@ -768,7 +768,8 @@
return nlmsg_end(skb, nlh);
nla_put_failure:
- return nlmsg_cancel(skb, nlh);
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
}
static void dn_ifaddr_notify(int event, struct dn_ifaddr *ifa)
@@ -781,9 +782,12 @@
goto errout;
err = dn_nl_fill_ifaddr(skb, ifa, 0, 0, event, 0);
- /* failure implies BUG in dn_ifaddr_nlmsg_size() */
- BUG_ON(err < 0);
-
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in dn_ifaddr_nlmsg_size() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
err = rtnl_notify(skb, 0, RTNLGRP_DECnet_IFADDR, NULL, GFP_KERNEL);
errout:
if (err < 0)
diff --git a/net/decnet/dn_table.c b/net/decnet/dn_table.c
index 13b2421..c1f0cc1 100644
--- a/net/decnet/dn_table.c
+++ b/net/decnet/dn_table.c
@@ -350,7 +350,7 @@
nlmsg_failure:
rtattr_failure:
skb_trim(skb, b - skb->data);
- return -1;
+ return -EMSGSIZE;
}
@@ -368,9 +368,12 @@
err = dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
f->fn_type, f->fn_scope, &f->fn_key, z,
DN_FIB_INFO(f), 0);
- /* failure implies BUG in dn_fib_nlmsg_size() */
- BUG_ON(err < 0);
-
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
err = rtnl_notify(skb, pid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
errout:
if (err < 0)
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 480ace9..c402036 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1140,7 +1140,7 @@
nlh = nlmsg_put(skb, pid, seq, event, sizeof(*ifm), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
ifm = nlmsg_data(nlh);
ifm->ifa_family = AF_INET;
@@ -1167,7 +1167,8 @@
return nlmsg_end(skb, nlh);
nla_put_failure:
- return nlmsg_cancel(skb, nlh);
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
}
static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
@@ -1225,9 +1226,12 @@
goto errout;
err = inet_fill_ifaddr(skb, ifa, pid, seq, event, 0);
- /* failure implies BUG in inet_nlmsg_size() */
- BUG_ON(err < 0);
-
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in inet_nlmsg_size() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
err = rtnl_notify(skb, pid, RTNLGRP_IPV4_IFADDR, nlh, GFP_KERNEL);
errout:
if (err < 0)
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index e63b8a9..be1028c 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -314,9 +314,12 @@
err = fib_dump_info(skb, info->pid, seq, event, tb_id,
fa->fa_type, fa->fa_scope, key, dst_len,
fa->fa_tos, fa->fa_info, 0);
- /* failure implies BUG in fib_nlmsg_size() */
- BUG_ON(err < 0);
-
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in fib_nlmsg_size() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
err = rtnl_notify(skb, info->pid, RTNLGRP_IPV4_ROUTE,
info->nlh, GFP_KERNEL);
errout:
@@ -960,7 +963,7 @@
nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
rtm = nlmsg_data(nlh);
rtm->rtm_family = AF_INET;
@@ -1031,7 +1034,8 @@
return nlmsg_end(skb, nlh);
nla_put_failure:
- return nlmsg_cancel(skb, nlh);
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
}
/*
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 77761ac..9cd53ad 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -153,7 +153,7 @@
rtattr_failure:
nlmsg_failure:
skb_trim(skb, b - skb->data);
- return -1;
+ return -EMSGSIZE;
}
static int inet_twsk_diag_fill(struct inet_timewait_sock *tw,
@@ -209,7 +209,7 @@
return skb->len;
nlmsg_failure:
skb_trim(skb, previous_tail - skb->data);
- return -1;
+ return -EMSGSIZE;
}
static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
@@ -274,11 +274,14 @@
if (!rep)
goto out;
- if (sk_diag_fill(sk, rep, req->idiag_ext,
- NETLINK_CB(in_skb).pid,
- nlh->nlmsg_seq, 0, nlh) <= 0)
- BUG();
-
+ err = sk_diag_fill(sk, rep, req->idiag_ext,
+ NETLINK_CB(in_skb).pid,
+ nlh->nlmsg_seq, 0, nlh);
+ if (err < 0) {
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(rep);
+ goto out;
+ }
err = netlink_unicast(idiagnl, rep, NETLINK_CB(in_skb).pid,
MSG_DONTWAIT);
if (err > 0)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 2daa0dc..baee304 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2635,7 +2635,7 @@
nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
r = nlmsg_data(nlh);
r->rtm_family = AF_INET;
@@ -2718,7 +2718,8 @@
return nlmsg_end(skb, nlh);
nla_put_failure:
- return nlmsg_cancel(skb, nlh);
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
}
int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index e385469..fe5e1d8 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3117,7 +3117,7 @@
nlh = nlmsg_put(skb, pid, seq, event, sizeof(struct ifaddrmsg), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
put_ifaddrmsg(nlh, ifa->prefix_len, ifa->flags, rt_scope(ifa->scope),
ifa->idev->dev->ifindex);
@@ -3137,8 +3137,10 @@
}
if (nla_put(skb, IFA_ADDRESS, 16, &ifa->addr) < 0 ||
- put_cacheinfo(skb, ifa->cstamp, ifa->tstamp, preferred, valid) < 0)
- return nlmsg_cancel(skb, nlh);
+ put_cacheinfo(skb, ifa->cstamp, ifa->tstamp, preferred, valid) < 0) {
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
+ }
return nlmsg_end(skb, nlh);
}
@@ -3155,13 +3157,15 @@
nlh = nlmsg_put(skb, pid, seq, event, sizeof(struct ifaddrmsg), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
put_ifaddrmsg(nlh, 128, IFA_F_PERMANENT, scope, ifindex);
if (nla_put(skb, IFA_MULTICAST, 16, &ifmca->mca_addr) < 0 ||
put_cacheinfo(skb, ifmca->mca_cstamp, ifmca->mca_tstamp,
- INFINITY_LIFE_TIME, INFINITY_LIFE_TIME) < 0)
- return nlmsg_cancel(skb, nlh);
+ INFINITY_LIFE_TIME, INFINITY_LIFE_TIME) < 0) {
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
+ }
return nlmsg_end(skb, nlh);
}
@@ -3178,13 +3182,15 @@
nlh = nlmsg_put(skb, pid, seq, event, sizeof(struct ifaddrmsg), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
put_ifaddrmsg(nlh, 128, IFA_F_PERMANENT, scope, ifindex);
if (nla_put(skb, IFA_ANYCAST, 16, &ifaca->aca_addr) < 0 ||
put_cacheinfo(skb, ifaca->aca_cstamp, ifaca->aca_tstamp,
- INFINITY_LIFE_TIME, INFINITY_LIFE_TIME) < 0)
- return nlmsg_cancel(skb, nlh);
+ INFINITY_LIFE_TIME, INFINITY_LIFE_TIME) < 0) {
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
+ }
return nlmsg_end(skb, nlh);
}
@@ -3334,9 +3340,12 @@
err = inet6_fill_ifaddr(skb, ifa, NETLINK_CB(in_skb).pid,
nlh->nlmsg_seq, RTM_NEWADDR, 0);
- /* failure implies BUG in inet6_ifaddr_msgsize() */
- BUG_ON(err < 0);
-
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in inet6_ifaddr_msgsize() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout_ifa;
+ }
err = rtnl_unicast(skb, NETLINK_CB(in_skb).pid);
errout_ifa:
in6_ifa_put(ifa);
@@ -3354,9 +3363,12 @@
goto errout;
err = inet6_fill_ifaddr(skb, ifa, 0, 0, event, 0);
- /* failure implies BUG in inet6_ifaddr_msgsize() */
- BUG_ON(err < 0);
-
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in inet6_ifaddr_msgsize() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
err = rtnl_notify(skb, 0, RTNLGRP_IPV6_IFADDR, NULL, GFP_ATOMIC);
errout:
if (err < 0)
@@ -3426,7 +3438,7 @@
nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
hdr = nlmsg_data(nlh);
hdr->ifi_family = AF_INET6;
@@ -3469,7 +3481,8 @@
return nlmsg_end(skb, nlh);
nla_put_failure:
- return nlmsg_cancel(skb, nlh);
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
}
static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
@@ -3507,9 +3520,12 @@
goto errout;
err = inet6_fill_ifinfo(skb, idev, 0, 0, event, 0);
- /* failure implies BUG in inet6_if_nlmsg_size() */
- BUG_ON(err < 0);
-
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in inet6_if_nlmsg_size() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
err = rtnl_notify(skb, 0, RTNLGRP_IPV6_IFADDR, NULL, GFP_ATOMIC);
errout:
if (err < 0)
@@ -3533,7 +3549,7 @@
nlh = nlmsg_put(skb, pid, seq, event, sizeof(*pmsg), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
pmsg = nlmsg_data(nlh);
pmsg->prefix_family = AF_INET6;
@@ -3558,7 +3574,8 @@
return nlmsg_end(skb, nlh);
nla_put_failure:
- return nlmsg_cancel(skb, nlh);
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
}
static void inet6_prefix_notify(int event, struct inet6_dev *idev,
@@ -3572,9 +3589,12 @@
goto errout;
err = inet6_fill_prefix(skb, idev, pinfo, 0, 0, event, 0);
- /* failure implies BUG in inet6_prefix_nlmsg_size() */
- BUG_ON(err < 0);
-
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in inet6_prefix_nlmsg_size() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
err = rtnl_notify(skb, 0, RTNLGRP_IPV6_PREFIX, NULL, GFP_ATOMIC);
errout:
if (err < 0)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 5f0043c..f4fda80 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2040,7 +2040,7 @@
nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtm), flags);
if (nlh == NULL)
- return -ENOBUFS;
+ return -EMSGSIZE;
rtm = nlmsg_data(nlh);
rtm->rtm_family = AF_INET6;
@@ -2111,7 +2111,8 @@
return nlmsg_end(skb, nlh);
nla_put_failure:
- return nlmsg_cancel(skb, nlh);
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
}
int rt6_dump_route(struct rt6_info *rt, void *p_arg)
@@ -2222,9 +2223,12 @@
goto errout;
err = rt6_fill_node(skb, rt, NULL, NULL, 0, event, pid, seq, 0, 0);
- /* failure implies BUG in rt6_nlmsg_size() */
- BUG_ON(err < 0);
-
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
err = rtnl_notify(skb, pid, RTNLGRP_IPV6_ROUTE, nlh, gfp_any());
errout:
if (err < 0)