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RDMA/ucma: reject AF_IB ip multicast requests

PATCH In review Greg Thelen 1 participant 2 messages Mar 30, 2018 – Mar 31, 2018 InfiniBand

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Greg Thelen

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#0 lore raw

PATCH 1/1 RDMA/ucma: reject AF_IB ip multicast requests

syzbot discovered that ucma_join_ip_multicast() mishandles AF_IB request addresses. If an RDMA_USER_CM_CMD_JOIN_IP_MCAST request has cmd.addr.sa_family=AF_IB then ucma_join_ip_multicast() reads beyond the end of its cmd.addr.

Reject non IP RDMA_USER_CM_CMD_JOIN_IP_MCAST requests. RDMA_USER_CM_CMD_JOIN_MCAST is interface for AF_IB multicast.

And add a buffer length safety check.

Fixes 5bc2b7b397b0 ("RDMA/ucma: Allow user space to specify AF_IB when joining multicast")
Signed-off-by Greg Thelen <[email protected]>
---
 drivers/infiniband/core/ucma.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)
drivers/infiniband/core/ucma.c +9 -1
index e5a1e7d81326..e410e03940ff 100644
@@ -1423,11 +1423,19 @@ static ssize_t ucma_join_ip_multicast(struct ucma_file *file,
 	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
 		return -EFAULT;
 
+	switch (cmd.addr.sin6_family) {
+	case AF_INET:
+	case AF_INET6:
+		break;
+	default:
+		return -EINVAL;
+	}
+
 	join_cmd.response = cmd.response;
 	join_cmd.uid = cmd.uid;
 	join_cmd.id = cmd.id;
 	join_cmd.addr_size = rdma_addr_size((struct sockaddr *) &cmd.addr);
-	if (!join_cmd.addr_size)
+	if (!join_cmd.addr_size || join_cmd.addr_size > sizeof(cmd.addr))
 		return -EINVAL;
 
 	join_cmd.join_flags = RDMA_MC_JOIN_FLAG_FULLMEMBER;
Signature · 1 line
2.17.0.rc1.321.gba9d0f2565-goog
author
#1 lore raw
Quoted 8 lines · Greg Thelen

syzbot discovered that ucma_join_ip_multicast() mishandles AF_IB request addresses. If an RDMA_USER_CM_CMD_JOIN_IP_MCAST request has cmd.addr.sa_family=AF_IB then ucma_join_ip_multicast() reads beyond the end of its cmd.addr.

Reject non IP RDMA_USER_CM_CMD_JOIN_IP_MCAST requests. RDMA_USER_CM_CMD_JOIN_MCAST is interface for AF_IB multicast.

Quoted 7 lines

And add a buffer length safety check.

Fixes 5bc2b7b397b0 ("RDMA/ucma: Allow user space to specify AF_IB when joining multicast")
Signed-off-by Greg Thelen <[email protected]>
---
 drivers/infiniband/core/ucma.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

My patch is no longer needed. linus/master recently picked up 84652aefb347 ("RDMA/ucma: Introduce safer rdma_addr_size() variants") which fixes the same issue.

Quoted 28 lines
drivers/infiniband/core/ucma.c +9 -2
index e5a1e7d81326..e410e03940ff 100644
@@ -1423,11 +1423,19 @@ static ssize_t ucma_join_ip_multicast(struct ucma_file *file,
        if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
                return -EFAULT;
 
+       switch (cmd.addr.sin6_family) {
+       case AF_INET:
+       case AF_INET6:
+               break;
+       default:
+               return -EINVAL;
+       }
+
        join_cmd.response = cmd.response;
        join_cmd.uid = cmd.uid;
        join_cmd.id = cmd.id;
        join_cmd.addr_size = rdma_addr_size((struct sockaddr *) &cmd.addr);
-       if (!join_cmd.addr_size)
+       if (!join_cmd.addr_size || join_cmd.addr_size > sizeof(cmd.addr))
                return -EINVAL;
 
        join_cmd.join_flags = RDMA_MC_JOIN_FLAG_FULLMEMBER;
--

2.17.0.rc1.321.gba9d0f2565-goog