[PATCH iproute2-next] rdma: Check comm string before print in print_comm()

[PATCH iproute2-next] rdma: Check comm string before print in print_comm()

[Leon Romanovsky]

From: Mark Zhang <markz@mellanox.com>

Broken kernels (not-upstream) can provide wrong empty "comm" field.
It causes to segfault while printing in JSON format.

Fixes: 8ecac46a60ff ("rdma: Add QP resource tracking information")
Signed-off-by: Mark Zhang <markz@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
---
 rdma/res.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/rdma/res.c b/rdma/res.c
index 97a7b964..6003006e 100644
--- a/rdma/res.c
+++ b/rdma/res.c
@@ -161,6 +161,9 @@ void print_comm(struct rd *rd, const char *str, struct nlattr **nla_line)
 {
 	char tmp[18];
 
+	if (!str)
+		return;
+
 	if (rd->json_output) {
 		/* Don't beatify output in JSON format */
 		jsonw_string_field(rd->jw, "comm", str);
-- 
2.20.1

Re: [PATCH iproute2-next] rdma: Check comm string before print in print_comm()

[David Ahern]

On 9/11/19 2:12 AM, Leon Romanovsky wrote:
> From: Mark Zhang <markz@mellanox.com>
> 
> Broken kernels (not-upstream) can provide wrong empty "comm" field.
> It causes to segfault while printing in JSON format.
> 
> Fixes: 8ecac46a60ff ("rdma: Add QP resource tracking information")

that commit is from 2018, so this should go to master; re-assigned in
patchwork.

> Signed-off-by: Mark Zhang <markz@mellanox.com>
> Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
> ---
>  rdma/res.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/rdma/res.c b/rdma/res.c
> index 97a7b964..6003006e 100644
> --- a/rdma/res.c
> +++ b/rdma/res.c
> @@ -161,6 +161,9 @@ void print_comm(struct rd *rd, const char *str, struct nlattr **nla_line)
>  {
>  	char tmp[18];
>  
> +	if (!str)
> +		return;
> +
>  	if (rd->json_output) {
>  		/* Don't beatify output in JSON format */
>  		jsonw_string_field(rd->jw, "comm", str);
> 

Re: [PATCH iproute2-next] rdma: Check comm string before print in print_comm()

[Leon Romanovsky]

On Sun, Sep 15, 2019 at 11:47:19AM -0600, David Ahern wrote:
> On 9/11/19 2:12 AM, Leon Romanovsky wrote:
> > From: Mark Zhang <markz@mellanox.com>
> >
> > Broken kernels (not-upstream) can provide wrong empty "comm" field.
> > It causes to segfault while printing in JSON format.
> >
> > Fixes: 8ecac46a60ff ("rdma: Add QP resource tracking information")
>
> that commit is from 2018, so this should go to master; re-assigned in
> patchwork.

This is exactly why I sent it to -next, it is not urgent :)

Thanks