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authorPhil Sutter <phil@nwl.cc>2024-11-29 16:30:38 +0100
committerPablo Neira Ayuso <pablo@netfilter.org>2024-12-04 15:39:22 +0100
commit456f010bfaefde84d3390c755eedb1b0a5857c3c (patch)
tree91bf2f49fc03be087674f0b33deb94c875ff6959 /net
parent7b1d83da254be3bf054965c8f3b1ad976f460ae5 (diff)
netfilter: ipset: Hold module reference while requesting a module
User space may unload ip_set.ko while it is itself requesting a set type backend module, leading to a kernel crash. The race condition may be provoked by inserting an mdelay() right after the nfnl_unlock() call. Fixes: a7b4f989a629 ("netfilter: ipset: IP set core support") Signed-off-by: Phil Sutter <phil@nwl.cc> Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/ipset/ip_set_core.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
index 61431690cbd5..cc20e6d56807 100644
--- a/net/netfilter/ipset/ip_set_core.c
+++ b/net/netfilter/ipset/ip_set_core.c
@@ -104,14 +104,19 @@ find_set_type(const char *name, u8 family, u8 revision)
static bool
load_settype(const char *name)
{
+ if (!try_module_get(THIS_MODULE))
+ return false;
+
nfnl_unlock(NFNL_SUBSYS_IPSET);
pr_debug("try to load ip_set_%s\n", name);
if (request_module("ip_set_%s", name) < 0) {
pr_warn("Can't find ip_set type %s\n", name);
nfnl_lock(NFNL_SUBSYS_IPSET);
+ module_put(THIS_MODULE);
return false;
}
nfnl_lock(NFNL_SUBSYS_IPSET);
+ module_put(THIS_MODULE);
return true;
}