[openwrt/openwrt] netifd: add missing error checks to packet steering script

[LEDE Commits]

nbd pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/123282d9f9edf361729c2e8bb410957a6844d845

commit 123282d9f9edf361729c2e8bb410957a6844d845
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Mon Apr 15 12:32:35 2024 +0200

    netifd: add missing error checks to packet steering script
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 .../config/netifd/files/usr/libexec/network/packet-steering.uc     | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/package/network/config/netifd/files/usr/libexec/network/packet-steering.uc b/package/network/config/netifd/files/usr/libexec/network/packet-steering.uc
index f146a96e41..72f96024d8 100755
--- a/package/network/config/netifd/files/usr/libexec/network/packet-steering.uc
+++ b/package/network/config/netifd/files/usr/libexec/network/packet-steering.uc
@@ -27,6 +27,8 @@ for (let arg in ARGV) {
 function task_name(pid)
 {
 	let stat = open(`/proc/${pid}/status`, "r");
+	if (!stat)
+		return;
 	let line = stat.read("line");
 	stat.close();
 	return trim(split(line, "\t", 2)[1]);
@@ -35,8 +37,11 @@ function task_name(pid)
 function set_task_cpu(pid, cpu) {
 	if (disable)
 		cpu = join(",", map(cpus, (cpu) => cpu.id));
+	let name = task_name(pid);
+	if (!name)
+		return;
 	if (debug || do_nothing)
-		warn(`taskset -p -c ${cpu} ${task_name(pid)}\n`);
+		warn(`taskset -p -c ${cpu} ${name}\n`);
 	if (!do_nothing)
 		system(`taskset -p -c ${cpu} ${pid}`);
 }