| Message ID | 20250212-rtnetlink_leak-v1-1-27bce9a3ac9a@bootlin.com (mailing list archive) |
|---|---|
| State | Rejected |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | rtnetlink: Fix small memory leaks | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Clearly marked for net |
| netdev/apply | fail | Patch does not apply to net-0 |
From: "Bastien Curutchet (eBPF Foundation)" <bastien.curutchet@bootlin.com> Date: Wed, 12 Feb 2025 09:23:47 +0100 > rtnl_net_cmp_locks() always returns -1 if CONFIG_DEBUG_NET_SMALL_RTNL is > disabled. However, if CONFIG_DEBUG_NET_SMALL_RTNL is enabled, it returns 0 > when both inputs are equal. It is then used by rtnl_nets_add() to call > put_net() if the net to be added is already present in the struct > rtnl_nets. As a result, when rtnl_nets_add() is called on an already > present net, put_net() is called only if DEBUG is on. If CONFIG_DEBUG_NET_SMALL_RTNL is disabled, every duplicate net is added to rtnl_nets, so put_net() is expected to be called for each in rtnl_nets_destroy().
On 2/12/25 9:45 AM, Kuniyuki Iwashima wrote: > From: "Bastien Curutchet (eBPF Foundation)" <bastien.curutchet@bootlin.com> > Date: Wed, 12 Feb 2025 09:23:47 +0100 >> rtnl_net_cmp_locks() always returns -1 if CONFIG_DEBUG_NET_SMALL_RTNL is >> disabled. However, if CONFIG_DEBUG_NET_SMALL_RTNL is enabled, it returns 0 >> when both inputs are equal. It is then used by rtnl_nets_add() to call >> put_net() if the net to be added is already present in the struct >> rtnl_nets. As a result, when rtnl_nets_add() is called on an already >> present net, put_net() is called only if DEBUG is on. > > If CONFIG_DEBUG_NET_SMALL_RTNL is disabled, every duplicate net is > added to rtnl_nets, so put_net() is expected to be called for each > in rtnl_nets_destroy(). I see, sorry for the irrelevant series then ... Best regards, Bastien
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index cb7fad8d1f95ff287810229c341de6a6d20a9c07..94111d3383788566f2296039e68549e2b40d5a4a 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -275,6 +275,9 @@ EXPORT_SYMBOL(lockdep_rtnl_net_is_held); #else static int rtnl_net_cmp_locks(const struct net *net_a, const struct net *net_b) { + if (net_eq(net_a, net_b)) + return 0; + /* No need to swap */ return -1; }
rtnl_net_cmp_locks() always returns -1 if CONFIG_DEBUG_NET_SMALL_RTNL is disabled. However, if CONFIG_DEBUG_NET_SMALL_RTNL is enabled, it returns 0 when both inputs are equal. It is then used by rtnl_nets_add() to call put_net() if the net to be added is already present in the struct rtnl_nets. As a result, when rtnl_nets_add() is called on an already present net, put_net() is called only if DEBUG is on. Add the input comparison in the DEBUG off case so that put_net() is always called in this scenario. Fixes: cbaaa6326bc5 ("rtnetlink: Introduce struct rtnl_nets and helpers.") Cc: stable@vger.kernel.org Signed-off-by: Bastien Curutchet (eBPF Foundation) <bastien.curutchet@bootlin.com> --- net/core/rtnetlink.c | 3 +++ 1 file changed, 3 insertions(+)