File _service:download_files:163b384..745fd240.patch of Package linux-px

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File _service:download_files:163b384..745fd240.patch of Package linux-px (Revision f40d4c93852def3b00c899b2b98ba38c)

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From ae662483baea9509808270e695d319e934f7eabf Mon Sep 17 00:00:00 2001
From: "Jan Alexander Steffens (heftig)" <jan.steffens@gmail.com>
Date: Mon, 16 Sep 2019 04:53:20 +0200
Subject: [PATCH 1/3] ZEN: Add sysctl and CONFIG to disallow unprivileged
 CLONE_NEWUSER

Our default behavior continues to match the vanilla kernel.
---
 include/linux/user_namespace.h |  4 ++++
 init/Kconfig                   | 16 ++++++++++++++++
 kernel/fork.c                  | 14 ++++++++++++++
 kernel/sysctl.c                | 12 ++++++++++++
 kernel/user_namespace.c        |  7 +++++++
 5 files changed, 53 insertions(+)

diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index 6030a823561735..60b7fe5fa74ad4 100644
--- a/include/linux/user_namespace.h
+++ b/include/linux/user_namespace.h
@@ -156,6 +156,8 @@ static inline void set_userns_rlimit_max(struct user_namespace *ns,
 
 #ifdef CONFIG_USER_NS
 
+extern int unprivileged_userns_clone;
+
 static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
 {
 	if (ns)
@@ -189,6 +191,8 @@ extern bool current_in_userns(const struct user_namespace *target_ns);
 struct ns_common *ns_get_owner(struct ns_common *ns);
 #else
 
+#define unprivileged_userns_clone 0
+
 static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
 {
 	return &init_user_ns;
diff --git a/init/Kconfig b/init/Kconfig
index 5783a0b8751726..5ea91114707c5c 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1265,6 +1265,22 @@ config USER_NS
 
 	  If unsure, say N.
 
+config USER_NS_UNPRIVILEGED
+	bool "Allow unprivileged users to create namespaces"
+	default y
+	depends on USER_NS
+	help
+	  When disabled, unprivileged users will not be able to create
+	  new namespaces. Allowing users to create their own namespaces
+	  has been part of several recent local privilege escalation
+	  exploits, so if you need user namespaces but are
+	  paranoid^Wsecurity-conscious you want to disable this.
+
+	  This setting can be overridden at runtime via the
+	  kernel.unprivileged_userns_clone sysctl.
+
+	  If unsure, say Y.
+
 config PID_NS
 	bool "PID Namespaces"
 	default y
diff --git a/kernel/fork.c b/kernel/fork.c
index 6b97fb2ac4af56..003de4829c153e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -105,6 +105,10 @@
 #include <uapi/linux/pidfd.h>
 #include <linux/pidfs.h>
 
+#ifdef CONFIG_USER_NS
+#include <linux/user_namespace.h>
+#endif
+
 #include <asm/pgalloc.h>
 #include <linux/uaccess.h>
 #include <asm/mmu_context.h>
@@ -2135,6 +2139,10 @@ __latent_entropy struct task_struct *copy_process(
 	if ((clone_flags & (CLONE_NEWUSER|CLONE_FS)) == (CLONE_NEWUSER|CLONE_FS))
 		return ERR_PTR(-EINVAL);
 
+	if ((clone_flags & CLONE_NEWUSER) && !unprivileged_userns_clone)
+		if (!capable(CAP_SYS_ADMIN))
+			return ERR_PTR(-EPERM);
+
 	/*
 	 * Thread groups must share signals as well, and detached threads
 	 * can only be started up within the thread group.
@@ -3283,6 +3291,12 @@ int ksys_unshare(unsigned long unshare_flags)
 	if (unshare_flags & CLONE_NEWNS)
 		unshare_flags |= CLONE_FS;
 
+	if ((unshare_flags & CLONE_NEWUSER) && !unprivileged_userns_clone) {
+		err = -EPERM;
+		if (!capable(CAP_SYS_ADMIN))
+			goto bad_unshare_out;
+	}
+
 	err = check_unshare_flags(unshare_flags);
 	if (err)
 		goto bad_unshare_out;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 79e6cb1d5c48f8..676e89dc38c339 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -80,6 +80,9 @@
 #ifdef CONFIG_RT_MUTEXES
 #include <linux/rtmutex.h>
 #endif
+#ifdef CONFIG_USER_NS
+#include <linux/user_namespace.h>
+#endif
 
 /* shared constants to be used in various sysctls */
 const int sysctl_vals[] = { 0, 1, 2, 3, 4, 100, 200, 1000, 3000, INT_MAX, 65535, -1 };
@@ -1618,6 +1621,15 @@ static struct ctl_table kern_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
+#ifdef CONFIG_USER_NS
+	{
+		.procname	= "unprivileged_userns_clone",
+		.data		= &unprivileged_userns_clone,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+#endif
 #ifdef CONFIG_PROC_SYSCTL
 	{
 		.procname	= "tainted",
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 0b0b95418b16a7..c4b835b91fc005 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -22,6 +22,13 @@
 #include <linux/bsearch.h>
 #include <linux/sort.h>
 
+/* sysctl */
+#ifdef CONFIG_USER_NS_UNPRIVILEGED
+int unprivileged_userns_clone = 1;
+#else
+int unprivileged_userns_clone;
+#endif
+
 static struct kmem_cache *user_ns_cachep __ro_after_init;
 static DEFINE_MUTEX(userns_state_mutex);

From f149c552394709e0106c6f7a5788080fd63791af Mon Sep 17 00:00:00 2001
From: "Jan Alexander Steffens (heftig)" <heftig@archlinux.org>
Date: Sat, 13 Jan 2024 15:29:25 +0100
Subject: [PATCH 2/3] arch/Kconfig: Default to maximum amount of ASLR bits

To mitigate https://zolutal.github.io/aslrnt/; do this with a patch to
avoid having to enable `CONFIG_EXPERT`.
---
 arch/Kconfig | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index 975dd22a2dbd22..de69b8f5b5be85 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -1050,7 +1050,7 @@ config ARCH_MMAP_RND_BITS
 	int "Number of bits to use for ASLR of mmap base address" if EXPERT
 	range ARCH_MMAP_RND_BITS_MIN ARCH_MMAP_RND_BITS_MAX
 	default ARCH_MMAP_RND_BITS_DEFAULT if ARCH_MMAP_RND_BITS_DEFAULT
-	default ARCH_MMAP_RND_BITS_MIN
+	default ARCH_MMAP_RND_BITS_MAX
 	depends on HAVE_ARCH_MMAP_RND_BITS
 	help
 	  This value can be used to select the number of bits to use to
@@ -1084,7 +1084,7 @@ config ARCH_MMAP_RND_COMPAT_BITS
 	int "Number of bits to use for ASLR of mmap base address for compatible applications" if EXPERT
 	range ARCH_MMAP_RND_COMPAT_BITS_MIN ARCH_MMAP_RND_COMPAT_BITS_MAX
 	default ARCH_MMAP_RND_COMPAT_BITS_DEFAULT if ARCH_MMAP_RND_COMPAT_BITS_DEFAULT
-	default ARCH_MMAP_RND_COMPAT_BITS_MIN
+	default ARCH_MMAP_RND_COMPAT_BITS_MAX
 	depends on HAVE_ARCH_MMAP_RND_COMPAT_BITS
 	help
 	  This value can be used to select the number of bits to use to

From 745fd24004bb4144cbf345bc516246b1cce16204 Mon Sep 17 00:00:00 2001
From: Javier Martinez Canillas <javierm@redhat.com>
Date: Thu, 19 May 2022 14:40:07 +0200
Subject: [PATCH 3/3] drivers/firmware: skip simpledrm if nvidia-drm.modeset=1
 is set

The Nvidia proprietary driver has some bugs that leads to issues if used
with the simpledrm driver. The most noticeable is that does not register
an emulated fbdev device.

It just relies on a fbdev to be registered by another driver, that could
be that could be attached to the framebuffer console. On UEFI machines,
this is the efifb driver.

This means that disabling the efifb driver will cause virtual consoles to
not be present in the system when using the Nvidia driver. Legacy BIOS is
not affected just because fbcon is not used there, but instead vgacon.

Unless a VGA mode is specified using the vga= kernel command line option,
in that case the vesafb driver is used instead and its fbdev attached to
the fbcon.

This is a problem because with CONFIG_SYSFB_SIMPLEFB=y, the sysfb platform
code attempts to register a "simple-framebuffer" platform device (that is
matched against simpledrm) and only registers either an "efi-framebuffer"
or "vesa-framebuffer" if this fails to be registered due the video modes
not being compatible.

The Nvidia driver relying on another driver to register the fbdev is quite
fragile, since it can't really assume those will stick around. For example
there are patches posted to remove the EFI and VESA platform devices once
a real DRM or fbdev driver probes.

But in any case, moving to a simpledrm + emulated fbdev only breaks this
assumption and causes users to not have VT if the Nvidia driver is used.

So to prevent this, let's add a workaround and make the sysfb to skip the
"simple-framebuffer" registration when nvidia-drm.modeset=1 option is set.

This is quite horrible, but honestly I can't think of any other approach.

For this to work, the CONFIG_FB_EFI and CONFIG_FB_VESA config options must
be enabled besides CONFIG_DRM_SIMPLEDRM.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Cherry-picked-for: https://bugs.archlinux.org/task/73720
---
 drivers/firmware/sysfb.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/sysfb.c b/drivers/firmware/sysfb.c
index a3df782fa687b0..940d8f51434176 100644
--- a/drivers/firmware/sysfb.c
+++ b/drivers/firmware/sysfb.c
@@ -35,6 +35,22 @@
 #include <linux/screen_info.h>
 #include <linux/sysfb.h>
 
+static int skip_simpledrm;
+
+static int __init simpledrm_disable(char *opt)
+{
+	if (!opt)
+                return -EINVAL;
+
+	get_option(&opt, &skip_simpledrm);
+
+	if (skip_simpledrm)
+		pr_info("The simpledrm driver will not be probed\n");
+
+	return 0;
+}
+early_param("nvidia-drm.modeset", simpledrm_disable);
+
 static struct platform_device *pd;
 static DEFINE_MUTEX(disable_lock);
 static bool disabled;
@@ -145,7 +161,7 @@ static __init int sysfb_init(void)
 
 	/* try to create a simple-framebuffer device */
 	compatible = sysfb_parse_mode(si, &mode);
-	if (compatible) {
+	if (compatible && !skip_simpledrm) {
 		pd = sysfb_create_simplefb(si, &mode, parent);
 		if (!IS_ERR(pd))
 			goto put_device;

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