[PATCH] net/ceph/messenger: support IPv6 Link-Local with scope identifier

[PATCH] net/ceph/messenger: support IPv6 Link-Local with scope identifier

[Max Kellermann]

Implement ceph_pton() using inet_pton_with_scope().  This minimal
patch preserves the ceph_pton() API and thus requires copying the
parameter to a null-terminated string.

Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
---
 net/ceph/messenger.c | 36 +++++++++++++++++++++++++++---------
 1 file changed, 27 insertions(+), 9 deletions(-)

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 34b3097b4c7b..4848ae5f61bb 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -1221,19 +1221,37 @@ void ceph_addr_set_port(struct ceph_entity_addr *addr, int p)
 static int ceph_pton(const char *str, size_t len, struct ceph_entity_addr *addr,
 		char delim, const char **ipend)
 {
-	memset(&addr->in_addr, 0, sizeof(addr->in_addr));
+	const char *delim_p;
+	char *copy;
+	struct sockaddr_storage stor = { 0 };
+	int ret;
 
-	if (in4_pton(str, len, (u8 *)&((struct sockaddr_in *)&addr->in_addr)->sin_addr.s_addr, delim, ipend)) {
-		put_unaligned(AF_INET, &addr->in_addr.ss_family);
-		return 0;
-	}
+	delim_p = memchr(str, delim, len);
+	if (delim_p)
+		/* delimiter was found - stop parsing there */
+		len = delim_p - str;
 
-	if (in6_pton(str, len, (u8 *)&((struct sockaddr_in6 *)&addr->in_addr)->sin6_addr.s6_addr, delim, ipend)) {
-		put_unaligned(AF_INET6, &addr->in_addr.ss_family);
-		return 0;
+	/* the input string might not be null terminated, so copy it
+	 * to a null-terminated string
+	 */
+	copy = kstrndup(str, len, GFP_NOFS);
+	if (!copy)
+		return -ENOMEM;
+
+	ret = inet_pton_with_scope(&init_net, AF_UNSPEC, copy, NULL, &stor);
+	kfree(copy);
+
+	if (!ret) {
+		/* ceph_entity_addr might be misaligned, so we have to
+		 * parse to a stack variable first
+		 */
+		memcpy(&addr->in_addr, &stor, sizeof(stor));
+
+		/* return the end of the parsed portion to the caller on success */
+		*ipend = str + len;
 	}
 
-	return -EINVAL;
+	return ret;
 }
 
 /*
-- 
2.47.3

Re: net/ceph/messenger: support IPv6 Link-Local with scope identifier

[Alex Markuze]

Hi Max,

NACK for now. Thanks for the patch, but I have some concerns
that need a v2:

  1. [critical] net/ceph/messenger.c:1251: NULL pointer dereference via ceph_dns_resolve_name
  2. [major] net/ceph/messenger.c:1251: IPv4 port parsing regression
  3. [major] net/ceph/messenger.c:1243: Scope resolution uses init_net instead of caller's namespace


-- 
Alex Markuze

Re: net/ceph/messenger: support IPv6 Link-Local with scope identifier

[Max Kellermann]

On Thu, Jul 2, 2026 at 1:40 PM Alex Markuze <amarkuze@redhat.com> wrote:
>
> Hi Max,
>
> NACK for now. Thanks for the patch, but I have some concerns
> that need a v2:
>
>   1. [critical] net/ceph/messenger.c:1251: NULL pointer dereference via ceph_dns_resolve_name
>   2. [major] net/ceph/messenger.c:1251: IPv4 port parsing regression

Need more information on these.

-- 
Max Kellermann
Principal Architect
Hosting Technology

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