BPF build fix

Signed-off-by: Justin M. Forbes <jforbes@fedoraproject.org>
This commit is contained in:
Justin M. Forbes 2021-06-01 11:08:30 -05:00
parent 1dfb87c0ec
commit efc0210f4b
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@ -2786,3 +2786,84 @@ index b38155b2de83..b0a6711b4825 100644
#ifdef CONFIG_PERF_EVENTS #ifdef CONFIG_PERF_EVENTS
int security_perf_event_open(struct perf_event_attr *attr, int type) int security_perf_event_open(struct perf_event_attr *attr, int type)
{ {
From d9b1c2752249db9fabd95de4b3656d66f348b671 Mon Sep 17 00:00:00 2001
From: Jiri Olsa <jolsa@kernel.org>
Date: Tue, 1 Jun 2021 14:15:11 +0200
Subject: [PATCH] bpf: Fix unprivileged_bpf_disabled setup
There's recent change [1] that adds new config option and sets
unprivileged_bpf_disabled to 2 if the option is enabled
(CONFIG_BPF_UNPRIV_DEFAULT_OFF).
The current RHEL specific behaviour is to set unprivileged_bpf_disabled
to 1 by default and add boot command line argument to enable
unpriv bpf.
The config option is enabled in previous patch, adding the taint
for proc/sysctl unprivileged_bpf_disabled setup.
[1] 08389d888287 ("bpf: Add kconfig knob for disabling unpriv bpf by default")
[2] 607f0e89af7e ("bpf: set unprivileged_bpf_disabled to 1 by default, add a boot parameter")
Fixes: 607f0e89af7e ("bpf: set unprivileged_bpf_disabled to 1 by default, add a boot parameter")
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
---
Documentation/admin-guide/kernel-parameters.txt | 7 ++++---
kernel/bpf/syscall.c | 3 ---
kernel/sysctl.c | 5 +++++
3 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 3d033c0b69f9..e4c7b7002d58 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -5765,12 +5765,13 @@
[X86] Cause panic on unknown NMI.
unprivileged_bpf_disabled=
- Format: { "0" | "1" }
+ Format: { "0" | "1" | "2" }
Sets the initial value of
kernel.unprivileged_bpf_disabled sysctl knob.
0 - unprivileged bpf() syscall access is enabled.
- 1 - unprivileged bpf() syscall access is disabled.
- Default value is 1.
+ 1 - unprivileged bpf() syscall access is disabled permanently.
+ 2 - unprivileged bpf() syscall access is disabled.
+ Default value is 2.
usbcore.authorized_default=
[USB] Default USB device authorization:
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 88925c1887b7..cb37c3f119cf 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -51,9 +51,6 @@ static DEFINE_SPINLOCK(map_idr_lock);
static DEFINE_IDR(link_idr);
static DEFINE_SPINLOCK(link_idr_lock);
-/* RHEL-only: default to 1 */
-int sysctl_unprivileged_bpf_disabled __read_mostly = 1;
-
static int __init unprivileged_bpf_setup(char *str)
{
unsigned long disabled;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index d4a78e08f6d8..cfb0ff48394d 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -241,6 +241,11 @@ static int bpf_unpriv_handler(struct ctl_table *table, int write,
if (write && !ret) {
if (locked_state && unpriv_enable != 1)
return -EPERM;
+ if (!unpriv_enable) {
+ pr_warn("Unprivileged BPF has been enabled, "
+ "tainting the kernel");
+ add_taint(TAINT_UNPRIVILEGED_BPF, LOCKDEP_STILL_OK);
+ }
*(int *)table->data = unpriv_enable;
}
return ret;
--
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