From: Stephen Hemminger <stephen@networkplumber•org>
To: Jamal Hadi Salim <jhs@mojatatu•com>
Cc: netdev@vger•kernel.org, dsahern@gmail•com, aclaudi@redhat•com,
daniel@iogearbox•net, asmadeus@codewreck•org,
Jamal Hadi Salim <hadi@mojatatu•com>
Subject: Re: [PATCH iproute2 v2 1/2] bpf: Fix segfault when custom pinning is used
Date: Wed, 22 Apr 2020 09:35:31 -0700 [thread overview]
Message-ID: <20200422093531.4d9364c9@hermes.lan> (raw)
In-Reply-To: <20200422102808.9197-2-jhs@emojatatu.com>
On Wed, 22 Apr 2020 06:28:07 -0400
Jamal Hadi Salim <jhs@mojatatu•com> wrote:
> From: Jamal Hadi Salim <hadi@mojatatu•com>
>
This is not a sufficient commit message. You need to describe what the
problem is and why this fixes it.
> Fixes: c0325b06382 ("bpf: replace snprintf with asprintf when dealing with long buffers")
>
> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu•com>
> ---
> lib/bpf.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/lib/bpf.c b/lib/bpf.c
> index 10cf9bf4..656cad02 100644
> --- a/lib/bpf.c
> +++ b/lib/bpf.c
> @@ -1509,15 +1509,15 @@ out:
> static int bpf_make_custom_path(const struct bpf_elf_ctx *ctx,
> const char *todo)
> {
> - char *tmp = NULL;
> + char tmp[PATH_MAX] = {};
Initializing the whole string to 0 is over kill here.
> char *rem = NULL;
> char *sub;
> int ret;
>
> - ret = asprintf(&tmp, "%s/../", bpf_get_work_dir(ctx->type));
> + ret = snprintf(tmp, PATH_MAX, "%s/../", bpf_get_work_dir(ctx->type));
snprintf will never return -1.
> if (ret < 0) {
> - fprintf(stderr, "asprintf failed: %s\n", strerror(errno));
> - goto out;
> + fprintf(stderr, "snprintf failed: %s\n", strerror(errno));
> + return ret;
> }
>
> ret = asprintf(&rem, "%s/", todo);
> @@ -1547,7 +1547,6 @@ static int bpf_make_custom_path(const struct bpf_elf_ctx *ctx,
> ret = 0;
> out:
> free(rem);
> - free(tmp);
> return ret;
> }
>
This patch needs to be reworked.
next prev parent reply other threads:[~2020-04-22 16:35 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-22 10:28 [PATCH iproute2 v2 0/2] bpf: memory access fixes Jamal Hadi Salim
2020-04-22 10:28 ` [PATCH iproute2 v2 1/2] bpf: Fix segfault when custom pinning is used Jamal Hadi Salim
2020-04-22 12:24 ` Andrea Claudi
2020-04-22 14:43 ` Dominique Martinet
2020-04-22 17:07 ` Jamal Hadi Salim
2020-04-22 16:35 ` Stephen Hemminger [this message]
2020-04-22 17:19 ` Jamal Hadi Salim
2020-04-23 6:30 ` Dominique Martinet
2020-04-23 17:46 ` Jamal Hadi Salim
2020-04-22 10:28 ` [PATCH iproute2 v2 2/2] bpf: Fix mem leak and extraneous free() in error path Jamal Hadi Salim
2020-04-22 14:44 ` Dominique Martinet
2020-04-30 5:40 ` [PATCH iproute2 v2 0/2] bpf: memory access fixes Stephen Hemminger
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