diff options
| author | Sishuai Gong <sishuai.system@gmail.com> | 2023-08-10 15:12:42 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-08-30 16:27:16 +0200 |
| commit | bdd7c2ff41435f90b1ed29acca91ca0092d3bfef (patch) | |
| tree | a2c80c1c5bb5cf9d43e3ef9c3de885a13d4bfc95 | |
| parent | 38e5c37bfab1d88a1d4ba21129f7515b9bf63fa3 (diff) | |
ipvs: fix racy memcpy in proc_do_sync_threshold
[ Upstream commit 5310760af1d4fbea1452bfc77db5f9a680f7ae47 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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 07242503d74d..2bc82dabfe3b 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -1759,6 +1759,7 @@ static int proc_do_sync_threshold(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { + struct netns_ipvs *ipvs = table->extra2; int *valp = table->data; int val[2]; int rc; @@ -1768,6 +1769,7 @@ 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) { @@ -1777,6 +1779,7 @@ proc_do_sync_threshold(struct ctl_table *table, int write, else memcpy(valp, val, sizeof(val)); } + mutex_unlock(&ipvs->sync_mutex); return rc; } @@ -4034,6 +4037,7 @@ 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; |