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| author | Sishuai Gong <sishuai.system@gmail.com> | 2023-08-10 15:12:42 -0400 |
|---|---|---|
| committer | Florian Westphal <fw@strlen.de> | 2023-08-16 00:05:15 +0200 |
| commit | 5310760af1d4fbea1452bfc77db5f9a680f7ae47 (patch) | |
| tree | 52c1ffadb87df2163b19482708e37ca567bc1638 | |
| parent | 9bfab6d23a2865966a4f89a96536fbf23f83bc8c (diff) | |
| download | nf-5310760af1d4fbea1452bfc77db5f9a680f7ae47.tar.gz | |
ipvs: fix racy memcpy in proc_do_sync_threshold
When two threads run proc_do_sync_threshold() in parallel,
data races could happen between the two memcpy():
Thread-1 Thread-2
memcpy(val, valp, sizeof(val));
memcpy(valp, val, sizeof(val));
This race might mess up the (struct ctl_table *) table->data,
so we add a mutex lock to serialize them.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Link: https://lore.kernel.org/netdev/B6988E90-0A1E-4B85-BF26-2DAF6D482433@gmail.com/
Signed-off-by: Sishuai Gong <sishuai.system@gmail.com>
Acked-by: Simon Horman <horms@kernel.org>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
| -rw-r--r-- | net/netfilter/ipvs/ip_vs_ctl.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 62606fb44d0272..4bb0d90eca1cd6 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -1876,6 +1876,7 @@ static int proc_do_sync_threshold(struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { + struct netns_ipvs *ipvs = table->extra2; int *valp = table->data; int val[2]; int rc; @@ -1885,6 +1886,7 @@ proc_do_sync_threshold(struct ctl_table *table, int write, .mode = table->mode, }; + mutex_lock(&ipvs->sync_mutex); memcpy(val, valp, sizeof(val)); rc = proc_dointvec(&tmp, write, buffer, lenp, ppos); if (write) { @@ -1894,6 +1896,7 @@ proc_do_sync_threshold(struct ctl_table *table, int write, else memcpy(valp, val, sizeof(val)); } + mutex_unlock(&ipvs->sync_mutex); return rc; } @@ -4321,6 +4324,7 @@ static int __net_init ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs) ipvs->sysctl_sync_threshold[0] = DEFAULT_SYNC_THRESHOLD; ipvs->sysctl_sync_threshold[1] = DEFAULT_SYNC_PERIOD; tbl[idx].data = &ipvs->sysctl_sync_threshold; + tbl[idx].extra2 = ipvs; tbl[idx++].maxlen = sizeof(ipvs->sysctl_sync_threshold); ipvs->sysctl_sync_refresh_period = DEFAULT_SYNC_REFRESH_PERIOD; tbl[idx++].data = &ipvs->sysctl_sync_refresh_period; |