Re: [PATCH net] net: ipv4: do not send ICMP Redirect when peer allocation fails

On Thu, Jul 23, 2026 at 2:06 PM Eric Dumazet [off-list ref] wrote:

When inet_getpeer_v4() fails to allocate a peer entry under memory pressure
or tree size caps, ip_rt_send_redirect() previously fell back to sending an
un-rate-limited ICMP Redirect.

Because ICMP Redirect is not part of the global rate limit mask (sysctl_icmp_ratemask),
sending ICMP Redirects when peer == NULL creates an un-rate-limited ICMP packet storm.

Fix this by failing closed in ip_rt_send_redirect() when peer == NULL.

Fixes: a853c609504e ("inetpeer: do not get a refcount in inet_getpeer()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv4/route.c | 2 --
 1 file changed, 2 deletions(-)

I think I sent this patch too soon, I will send a V2 tomorrow.
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