* [PATCH net-next] inet: ipmr: fix data-races
@ 2025-01-13 17:15 Eric Dumazet
2025-01-14 0:35 ` David Ahern
2025-01-14 21:36 ` Jakub Kicinski
0 siblings, 2 replies; 4+ messages in thread
From: Eric Dumazet @ 2025-01-13 17:15 UTC (permalink / raw)
To: David S . Miller, Jakub Kicinski, Paolo Abeni
Cc: netdev, Simon Horman, David Ahern, eric.dumazet, Eric Dumazet
Following fields of 'struct mr_mfc' can be updated
concurrently (no lock protection) from ip_mr_forward()
and ip6_mr_forward()
- bytes
- pkt
- wrong_if
- lastuse
They also can be read from other functions.
Convert bytes, pkt and wrong_if to atomic_long_t,
and use READ_ONCE()/WRITE_ONCE() for lastuse.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
include/linux/mroute_base.h | 6 +++---
net/ipv4/ipmr.c | 28 ++++++++++++++--------------
net/ipv4/ipmr_base.c | 6 +++---
net/ipv6/ip6mr.c | 28 ++++++++++++++--------------
4 files changed, 34 insertions(+), 34 deletions(-)
diff --git a/include/linux/mroute_base.h b/include/linux/mroute_base.h
index 9dd4bf1572553ffbf41bade97393fac091797a8d..58a2401e4b551bad0eadb9c5d4c341ddad48b39b 100644
--- a/include/linux/mroute_base.h
+++ b/include/linux/mroute_base.h
@@ -146,9 +146,9 @@ struct mr_mfc {
unsigned long last_assert;
int minvif;
int maxvif;
- unsigned long bytes;
- unsigned long pkt;
- unsigned long wrong_if;
+ atomic_long_t bytes;
+ atomic_long_t pkt;
+ atomic_long_t wrong_if;
unsigned long lastuse;
unsigned char ttls[MAXVIFS];
refcount_t refcount;
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 99d8faa508e5325c653c920855a52f24b661618c..21ae7594a8525a0df01ce01b801d0075dada0959 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -831,7 +831,7 @@ static void ipmr_update_thresholds(struct mr_table *mrt, struct mr_mfc *cache,
cache->mfc_un.res.maxvif = vifi + 1;
}
}
- cache->mfc_un.res.lastuse = jiffies;
+ WRITE_ONCE(cache->mfc_un.res.lastuse, jiffies);
}
static int vif_add(struct net *net, struct mr_table *mrt,
@@ -1681,9 +1681,9 @@ int ipmr_ioctl(struct sock *sk, int cmd, void *arg)
rcu_read_lock();
c = ipmr_cache_find(mrt, sr->src.s_addr, sr->grp.s_addr);
if (c) {
- sr->pktcnt = c->_c.mfc_un.res.pkt;
- sr->bytecnt = c->_c.mfc_un.res.bytes;
- sr->wrong_if = c->_c.mfc_un.res.wrong_if;
+ sr->pktcnt = atomic_long_read(&c->_c.mfc_un.res.pkt);
+ sr->bytecnt = atomic_long_read(&c->_c.mfc_un.res.bytes);
+ sr->wrong_if = atomic_long_read(&c->_c.mfc_un.res.wrong_if);
rcu_read_unlock();
return 0;
}
@@ -1753,9 +1753,9 @@ int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
rcu_read_lock();
c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
if (c) {
- sr.pktcnt = c->_c.mfc_un.res.pkt;
- sr.bytecnt = c->_c.mfc_un.res.bytes;
- sr.wrong_if = c->_c.mfc_un.res.wrong_if;
+ sr.pktcnt = atomic_long_read(&c->_c.mfc_un.res.pkt);
+ sr.bytecnt = atomic_long_read(&c->_c.mfc_un.res.bytes);
+ sr.wrong_if = atomic_long_read(&c->_c.mfc_un.res.wrong_if);
rcu_read_unlock();
if (copy_to_user(arg, &sr, sizeof(sr)))
@@ -1988,9 +1988,9 @@ static void ip_mr_forward(struct net *net, struct mr_table *mrt,
int vif, ct;
vif = c->_c.mfc_parent;
- c->_c.mfc_un.res.pkt++;
- c->_c.mfc_un.res.bytes += skb->len;
- c->_c.mfc_un.res.lastuse = jiffies;
+ atomic_long_inc(&c->_c.mfc_un.res.pkt);
+ atomic_long_add(skb->len, &c->_c.mfc_un.res.bytes);
+ WRITE_ONCE(c->_c.mfc_un.res.lastuse, jiffies);
if (c->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
struct mfc_cache *cache_proxy;
@@ -2021,7 +2021,7 @@ static void ip_mr_forward(struct net *net, struct mr_table *mrt,
goto dont_forward;
}
- c->_c.mfc_un.res.wrong_if++;
+ atomic_long_inc(&c->_c.mfc_un.res.wrong_if);
if (true_vifi >= 0 && mrt->mroute_do_assert &&
/* pimsm uses asserts, when switching from RPT to SPT,
@@ -3029,9 +3029,9 @@ static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
if (it->cache != &mrt->mfc_unres_queue) {
seq_printf(seq, " %8lu %8lu %8lu",
- mfc->_c.mfc_un.res.pkt,
- mfc->_c.mfc_un.res.bytes,
- mfc->_c.mfc_un.res.wrong_if);
+ atomic_long_read(&mfc->_c.mfc_un.res.pkt),
+ atomic_long_read(&mfc->_c.mfc_un.res.bytes),
+ atomic_long_read(&mfc->_c.mfc_un.res.wrong_if));
for (n = mfc->_c.mfc_un.res.minvif;
n < mfc->_c.mfc_un.res.maxvif; n++) {
if (VIF_EXISTS(mrt, n) &&
diff --git a/net/ipv4/ipmr_base.c b/net/ipv4/ipmr_base.c
index f0af12a2f70bcdf5ba54321bf7ebebe798318abb..03b6eee407a24117612d2254c5eb72e78f39c196 100644
--- a/net/ipv4/ipmr_base.c
+++ b/net/ipv4/ipmr_base.c
@@ -263,9 +263,9 @@ int mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
lastuse = READ_ONCE(c->mfc_un.res.lastuse);
lastuse = time_after_eq(jiffies, lastuse) ? jiffies - lastuse : 0;
- mfcs.mfcs_packets = c->mfc_un.res.pkt;
- mfcs.mfcs_bytes = c->mfc_un.res.bytes;
- mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
+ mfcs.mfcs_packets = atomic_long_read(&c->mfc_un.res.pkt);
+ mfcs.mfcs_bytes = atomic_long_read(&c->mfc_un.res.bytes);
+ mfcs.mfcs_wrong_if = atomic_long_read(&c->mfc_un.res.wrong_if);
if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) ||
nla_put_u64_64bit(skb, RTA_EXPIRES, jiffies_to_clock_t(lastuse),
RTA_PAD))
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 578ff1336afeff7a9f468d54c8fc47fddcaedbbb..535e9f72514c06ad655e46d3200c14298f584d99 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -520,9 +520,9 @@ static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
if (it->cache != &mrt->mfc_unres_queue) {
seq_printf(seq, " %8lu %8lu %8lu",
- mfc->_c.mfc_un.res.pkt,
- mfc->_c.mfc_un.res.bytes,
- mfc->_c.mfc_un.res.wrong_if);
+ atomic_long_read(&mfc->_c.mfc_un.res.pkt),
+ atomic_long_read(&mfc->_c.mfc_un.res.bytes),
+ atomic_long_read(&mfc->_c.mfc_un.res.wrong_if));
for (n = mfc->_c.mfc_un.res.minvif;
n < mfc->_c.mfc_un.res.maxvif; n++) {
if (VIF_EXISTS(mrt, n) &&
@@ -884,7 +884,7 @@ static void ip6mr_update_thresholds(struct mr_table *mrt,
cache->mfc_un.res.maxvif = vifi + 1;
}
}
- cache->mfc_un.res.lastuse = jiffies;
+ WRITE_ONCE(cache->mfc_un.res.lastuse, jiffies);
}
static int mif6_add(struct net *net, struct mr_table *mrt,
@@ -1945,9 +1945,9 @@ int ip6mr_ioctl(struct sock *sk, int cmd, void *arg)
c = ip6mr_cache_find(mrt, &sr->src.sin6_addr,
&sr->grp.sin6_addr);
if (c) {
- sr->pktcnt = c->_c.mfc_un.res.pkt;
- sr->bytecnt = c->_c.mfc_un.res.bytes;
- sr->wrong_if = c->_c.mfc_un.res.wrong_if;
+ sr->pktcnt = atomic_long_read(&c->_c.mfc_un.res.pkt);
+ sr->bytecnt = atomic_long_read(&c->_c.mfc_un.res.bytes);
+ sr->wrong_if = atomic_long_read(&c->_c.mfc_un.res.wrong_if);
rcu_read_unlock();
return 0;
}
@@ -2017,9 +2017,9 @@ int ip6mr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
rcu_read_lock();
c = ip6mr_cache_find(mrt, &sr.src.sin6_addr, &sr.grp.sin6_addr);
if (c) {
- sr.pktcnt = c->_c.mfc_un.res.pkt;
- sr.bytecnt = c->_c.mfc_un.res.bytes;
- sr.wrong_if = c->_c.mfc_un.res.wrong_if;
+ sr.pktcnt = atomic_long_read(&c->_c.mfc_un.res.pkt);
+ sr.bytecnt = atomic_long_read(&c->_c.mfc_un.res.bytes);
+ sr.wrong_if = atomic_long_read(&c->_c.mfc_un.res.wrong_if);
rcu_read_unlock();
if (copy_to_user(arg, &sr, sizeof(sr)))
@@ -2142,9 +2142,9 @@ static void ip6_mr_forward(struct net *net, struct mr_table *mrt,
int true_vifi = ip6mr_find_vif(mrt, dev);
vif = c->_c.mfc_parent;
- c->_c.mfc_un.res.pkt++;
- c->_c.mfc_un.res.bytes += skb->len;
- c->_c.mfc_un.res.lastuse = jiffies;
+ atomic_long_inc(&c->_c.mfc_un.res.pkt);
+ atomic_long_add(skb->len, &c->_c.mfc_un.res.bytes);
+ WRITE_ONCE(c->_c.mfc_un.res.lastuse, jiffies);
if (ipv6_addr_any(&c->mf6c_origin) && true_vifi >= 0) {
struct mfc6_cache *cache_proxy;
@@ -2162,7 +2162,7 @@ static void ip6_mr_forward(struct net *net, struct mr_table *mrt,
* Wrong interface: drop packet and (maybe) send PIM assert.
*/
if (rcu_access_pointer(mrt->vif_table[vif].dev) != dev) {
- c->_c.mfc_un.res.wrong_if++;
+ atomic_long_inc(&c->_c.mfc_un.res.wrong_if);
if (true_vifi >= 0 && mrt->mroute_do_assert &&
/* pimsm uses asserts, when switching from RPT to SPT,
--
2.47.1.613.gc27f4b7a9f-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH net-next] inet: ipmr: fix data-races
2025-01-13 17:15 [PATCH net-next] inet: ipmr: fix data-races Eric Dumazet
@ 2025-01-14 0:35 ` David Ahern
2025-01-14 21:36 ` Jakub Kicinski
1 sibling, 0 replies; 4+ messages in thread
From: David Ahern @ 2025-01-14 0:35 UTC (permalink / raw)
To: Eric Dumazet, David S . Miller, Jakub Kicinski, Paolo Abeni
Cc: netdev, Simon Horman, eric.dumazet
On 1/13/25 10:15 AM, Eric Dumazet wrote:
> Following fields of 'struct mr_mfc' can be updated
> concurrently (no lock protection) from ip_mr_forward()
> and ip6_mr_forward()
>
> - bytes
> - pkt
> - wrong_if
> - lastuse
>
> They also can be read from other functions.
>
> Convert bytes, pkt and wrong_if to atomic_long_t,
> and use READ_ONCE()/WRITE_ONCE() for lastuse.
>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
> include/linux/mroute_base.h | 6 +++---
> net/ipv4/ipmr.c | 28 ++++++++++++++--------------
> net/ipv4/ipmr_base.c | 6 +++---
> net/ipv6/ip6mr.c | 28 ++++++++++++++--------------
> 4 files changed, 34 insertions(+), 34 deletions(-)
>
Reviewed-by: David Ahern <dsahern@kernel.org>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH net-next] inet: ipmr: fix data-races
2025-01-13 17:15 [PATCH net-next] inet: ipmr: fix data-races Eric Dumazet
2025-01-14 0:35 ` David Ahern
@ 2025-01-14 21:36 ` Jakub Kicinski
2025-01-14 21:59 ` Eric Dumazet
1 sibling, 1 reply; 4+ messages in thread
From: Jakub Kicinski @ 2025-01-14 21:36 UTC (permalink / raw)
To: Eric Dumazet
Cc: David S . Miller, Paolo Abeni, netdev, Simon Horman, David Ahern,
eric.dumazet
On Mon, 13 Jan 2025 17:15:09 +0000 Eric Dumazet wrote:
> Following fields of 'struct mr_mfc' can be updated
> concurrently (no lock protection) from ip_mr_forward()
> and ip6_mr_forward()
>
> - bytes
> - pkt
> - wrong_if
> - lastuse
>
> They also can be read from other functions.
>
> Convert bytes, pkt and wrong_if to atomic_long_t,
> and use READ_ONCE()/WRITE_ONCE() for lastuse.
Drivers poke into this:
drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.c:1006:43: error: invalid operands to binary != (have ‘atomic_long_t’ {aka ‘atomic64_t’} and ‘u64’ {aka ‘long long unsigned int’})
+ 1006 | if (mr_route->mfc->mfc_un.res.pkt != packets)
+ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^~
+ | |
+ | atomic_long_t {aka atomic64_t}
--
pw-bot: cr
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH net-next] inet: ipmr: fix data-races
2025-01-14 21:36 ` Jakub Kicinski
@ 2025-01-14 21:59 ` Eric Dumazet
0 siblings, 0 replies; 4+ messages in thread
From: Eric Dumazet @ 2025-01-14 21:59 UTC (permalink / raw)
To: Jakub Kicinski
Cc: David S . Miller, Paolo Abeni, netdev, Simon Horman, David Ahern,
eric.dumazet
On Tue, Jan 14, 2025 at 10:36 PM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Mon, 13 Jan 2025 17:15:09 +0000 Eric Dumazet wrote:
> > Following fields of 'struct mr_mfc' can be updated
> > concurrently (no lock protection) from ip_mr_forward()
> > and ip6_mr_forward()
> >
> > - bytes
> > - pkt
> > - wrong_if
> > - lastuse
> >
> > They also can be read from other functions.
> >
> > Convert bytes, pkt and wrong_if to atomic_long_t,
> > and use READ_ONCE()/WRITE_ONCE() for lastuse.
>
> Drivers poke into this:
>
> drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.c:1006:43: error: invalid operands to binary != (have ‘atomic_long_t’ {aka ‘atomic64_t’} and ‘u64’ {aka ‘long long unsigned int’})
> + 1006 | if (mr_route->mfc->mfc_un.res.pkt != packets)
> + | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^~
> + | |
> + | atomic_long_t {aka atomic64_t}
Oops, oh well, thanks, I will send a V2.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2025-01-13 17:15 [PATCH net-next] inet: ipmr: fix data-races Eric Dumazet
2025-01-14 0:35 ` David Ahern
2025-01-14 21:36 ` Jakub Kicinski
2025-01-14 21:59 ` Eric Dumazet
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