diff options
| author | Xin Xiong <xiongx18@fudan.edu.cn> | 2022-08-13 20:49:08 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-08-15 11:40:28 +0100 |
| commit | 7396ba87f1edf549284869451665c7c4e74ecd4f (patch) | |
| tree | e5a72a34df9286b9cae985c720a32398b8450a4d /net/ipv6/ndisc.c | |
| parent | 27b8d4d7a0cf442b7a0351fecc33b714f4208324 (diff) | |
net: fix potential refcount leak in ndisc_router_discovery()
The issue happens on specific paths in the function. After both the
object `rt` and `neigh` are grabbed successfully, when `lifetime` is
nonzero but the metric needs change, the function just deletes the
route and set `rt` to NULL. Then, it may try grabbing `rt` and `neigh`
again if above conditions hold. The function simply overwrite `neigh`
if succeeds or returns if fails, without decreasing the reference
count of previous `neigh`. This may result in memory leaks.
Fix it by decrementing the reference count of `neigh` in place.
Fixes: 6b2e04bc240f ("net: allow user to set metric on default route learned via Router Advertisement")
Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/ndisc.c')
| -rw-r--r-- | net/ipv6/ndisc.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 98453693e400..3a553494ff16 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -1378,6 +1378,9 @@ static void ndisc_router_discovery(struct sk_buff *skb) if (!rt && lifetime) { ND_PRINTK(3, info, "RA: adding default router\n"); + if (neigh) + neigh_release(neigh); + rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev, pref, defrtr_usr_metric); if (!rt) { |