5.10-stable patches

added patches:
	bpf-add-kconfig-knob-for-disabling-unpriv-bpf-by-default.patch

diff --git a/queue-5.10/bpf-add-kconfig-knob-for-disabling-unpriv-bpf-by-default.patch b/queue-5.10/bpf-add-kconfig-knob-for-disabling-unpriv-bpf-by-default.patch
new file mode 100644 (file)
index 0000000..8b1ca8a
--- /dev/null
+++ b/queue-5.10/bpf-add-kconfig-knob-for-disabling-unpriv-bpf-by-default.patch
@@ -0,0 +1,138 @@
+From 08389d888287c3823f80b0216766b71e17f0aba5 Mon Sep 17 00:00:00 2001
+From: Daniel Borkmann <daniel@iogearbox.net>
+Date: Tue, 11 May 2021 22:35:17 +0200
+Subject: bpf: Add kconfig knob for disabling unpriv bpf by default
+
+From: Daniel Borkmann <daniel@iogearbox.net>
+
+commit 08389d888287c3823f80b0216766b71e17f0aba5 upstream.
+
+Add a kconfig knob which allows for unprivileged bpf to be disabled by default.
+If set, the knob sets /proc/sys/kernel/unprivileged_bpf_disabled to value of 2.
+
+This still allows a transition of 2 -> {0,1} through an admin. Similarly,
+this also still keeps 1 -> {1} behavior intact, so that once set to permanently
+disabled, it cannot be undone aside from a reboot.
+
+We've also added extra2 with max of 2 for the procfs handler, so that an admin
+still has a chance to toggle between 0 <-> 2.
+
+Either way, as an additional alternative, applications can make use of CAP_BPF
+that we added a while ago.
+
+Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
+Signed-off-by: Alexei Starovoitov <ast@kernel.org>
+Link: https://lore.kernel.org/bpf/74ec548079189e4e4dffaeb42b8987bb3c852eee.1620765074.git.daniel@iogearbox.net
+Cc: Salvatore Bonaccorso <carnil@debian.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ Documentation/admin-guide/sysctl/kernel.rst |   17 +++++++++++++---
+ init/Kconfig                                |   10 +++++++++
+ kernel/bpf/syscall.c                        |    3 +-
+ kernel/sysctl.c                             |   29 +++++++++++++++++++++++-----
+ 4 files changed, 50 insertions(+), 9 deletions(-)
+
+--- a/Documentation/admin-guide/sysctl/kernel.rst
++++ b/Documentation/admin-guide/sysctl/kernel.rst
+@@ -1457,11 +1457,22 @@ unprivileged_bpf_disabled
+ =========================
+ 
+ Writing 1 to this entry will disable unprivileged calls to ``bpf()``;
+-once disabled, calling ``bpf()`` without ``CAP_SYS_ADMIN`` will return
+-``-EPERM``.
++once disabled, calling ``bpf()`` without ``CAP_SYS_ADMIN`` or ``CAP_BPF``
++will return ``-EPERM``. Once set to 1, this can't be cleared from the
++running kernel anymore.
+ 
+-Once set, this can't be cleared.
++Writing 2 to this entry will also disable unprivileged calls to ``bpf()``,
++however, an admin can still change this setting later on, if needed, by
++writing 0 or 1 to this entry.
+ 
++If ``BPF_UNPRIV_DEFAULT_OFF`` is enabled in the kernel config, then this
++entry will default to 2 instead of 0.
++
++= =============================================================
++0 Unprivileged calls to ``bpf()`` are enabled
++1 Unprivileged calls to ``bpf()`` are disabled without recovery
++2 Unprivileged calls to ``bpf()`` are disabled
++= =============================================================
+ 
+ watchdog
+ ========
+--- a/init/Kconfig
++++ b/init/Kconfig
+@@ -1722,6 +1722,16 @@ config BPF_JIT_DEFAULT_ON
+       def_bool ARCH_WANT_DEFAULT_BPF_JIT || BPF_JIT_ALWAYS_ON
+       depends on HAVE_EBPF_JIT && BPF_JIT
+ 
++config BPF_UNPRIV_DEFAULT_OFF
++      bool "Disable unprivileged BPF by default"
++      depends on BPF_SYSCALL
++      help
++        Disables unprivileged BPF by default by setting the corresponding
++        /proc/sys/kernel/unprivileged_bpf_disabled knob to 2. An admin can
++        still reenable it by setting it to 0 later on, or permanently
++        disable it by setting it to 1 (from which no other transition to
++        0 is possible anymore).
++
+ source "kernel/bpf/preload/Kconfig"
+ 
+ config USERFAULTFD
+--- a/kernel/bpf/syscall.c
++++ b/kernel/bpf/syscall.c
+@@ -50,7 +50,8 @@ static DEFINE_SPINLOCK(map_idr_lock);
+ static DEFINE_IDR(link_idr);
+ static DEFINE_SPINLOCK(link_idr_lock);
+ 
+-int sysctl_unprivileged_bpf_disabled __read_mostly;
++int sysctl_unprivileged_bpf_disabled __read_mostly =
++      IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
+ 
+ static const struct bpf_map_ops * const bpf_map_types[] = {
+ #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
+--- a/kernel/sysctl.c
++++ b/kernel/sysctl.c
+@@ -233,7 +233,27 @@ static int bpf_stats_handler(struct ctl_
+       mutex_unlock(&bpf_stats_enabled_mutex);
+       return ret;
+ }
+-#endif
++
++static int bpf_unpriv_handler(struct ctl_table *table, int write,
++                            void *buffer, size_t *lenp, loff_t *ppos)
++{
++      int ret, unpriv_enable = *(int *)table->data;
++      bool locked_state = unpriv_enable == 1;
++      struct ctl_table tmp = *table;
++
++      if (write && !capable(CAP_SYS_ADMIN))
++              return -EPERM;
++
++      tmp.data = &unpriv_enable;
++      ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
++      if (write && !ret) {
++              if (locked_state && unpriv_enable != 1)
++                      return -EPERM;
++              *(int *)table->data = unpriv_enable;
++      }
++      return ret;
++}
++#endif /* CONFIG_BPF_SYSCALL && CONFIG_SYSCTL */
+ 
+ /*
+  * /proc/sys support
+@@ -2626,10 +2646,9 @@ static struct ctl_table kern_table[] = {
+               .data           = &sysctl_unprivileged_bpf_disabled,
+               .maxlen         = sizeof(sysctl_unprivileged_bpf_disabled),
+               .mode           = 0644,
+-              /* only handle a transition from default "0" to "1" */
+-              .proc_handler   = proc_dointvec_minmax,
+-              .extra1         = SYSCTL_ONE,
+-              .extra2         = SYSCTL_ONE,
++              .proc_handler   = bpf_unpriv_handler,
++              .extra1         = SYSCTL_ZERO,
++              .extra2         = &two,
+       },
+       {
+               .procname       = "bpf_stats_enabled",

diff --git a/queue-5.10/series b/queue-5.10/series
index f90c23aa7f86b1df9ee332be4e9ee3fe98c27285..9f09dc2a6f6b45d971c483079b1da8bb8f9a8344 100644 (file)
--- a/queue-5.10/series
+++ b/queue-5.10/series
@@ -45,3 +45,4 @@ input-appletouch-initialize-work-before-device-registration.patch
 input-spaceball-fix-parsing-of-movement-data-packets.patch
 net-fix-use-after-free-in-tw_timer_handler.patch
 perf-script-fix-cpu-filtering-of-a-script-s-switch-events.patch
+bpf-add-kconfig-knob-for-disabling-unpriv-bpf-by-default.patch