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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /drivers/misc/lkdtm/bugs.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'drivers/misc/lkdtm/bugs.c')
-rw-r--r--drivers/misc/lkdtm/bugs.c630
1 files changed, 630 insertions, 0 deletions
diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
new file mode 100644
index 000000000..48821f4c2
--- /dev/null
+++ b/drivers/misc/lkdtm/bugs.c
@@ -0,0 +1,630 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This is for all the tests related to logic bugs (e.g. bad dereferences,
+ * bad alignment, bad loops, bad locking, bad scheduling, deep stacks, and
+ * lockups) along with other things that don't fit well into existing LKDTM
+ * test source files.
+ */
+#include "lkdtm.h"
+#include <linux/list.h>
+#include <linux/sched.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/task_stack.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+
+#if IS_ENABLED(CONFIG_X86_32) && !IS_ENABLED(CONFIG_UML)
+#include <asm/desc.h>
+#endif
+
+struct lkdtm_list {
+ struct list_head node;
+};
+
+/*
+ * Make sure our attempts to over run the kernel stack doesn't trigger
+ * a compiler warning when CONFIG_FRAME_WARN is set. Then make sure we
+ * recurse past the end of THREAD_SIZE by default.
+ */
+#if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0)
+#define REC_STACK_SIZE (_AC(CONFIG_FRAME_WARN, UL) / 2)
+#else
+#define REC_STACK_SIZE (THREAD_SIZE / 8UL)
+#endif
+#define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2)
+
+static int recur_count = REC_NUM_DEFAULT;
+
+static DEFINE_SPINLOCK(lock_me_up);
+
+/*
+ * Make sure compiler does not optimize this function or stack frame away:
+ * - function marked noinline
+ * - stack variables are marked volatile
+ * - stack variables are written (memset()) and read (buf[..] passed as arg)
+ * - function may have external effects (memzero_explicit())
+ * - no tail recursion possible
+ */
+static int noinline recursive_loop(int remaining)
+{
+ volatile char buf[REC_STACK_SIZE];
+ volatile int ret;
+
+ memset((void *)buf, remaining & 0xFF, sizeof(buf));
+ if (!remaining)
+ ret = 0;
+ else
+ ret = recursive_loop((int)buf[remaining % sizeof(buf)] - 1);
+ memzero_explicit((void *)buf, sizeof(buf));
+ return ret;
+}
+
+/* If the depth is negative, use the default, otherwise keep parameter. */
+void __init lkdtm_bugs_init(int *recur_param)
+{
+ if (*recur_param < 0)
+ *recur_param = recur_count;
+ else
+ recur_count = *recur_param;
+}
+
+static void lkdtm_PANIC(void)
+{
+ panic("dumptest");
+}
+
+static void lkdtm_BUG(void)
+{
+ BUG();
+}
+
+static int warn_counter;
+
+static void lkdtm_WARNING(void)
+{
+ WARN_ON(++warn_counter);
+}
+
+static void lkdtm_WARNING_MESSAGE(void)
+{
+ WARN(1, "Warning message trigger count: %d\n", ++warn_counter);
+}
+
+static void lkdtm_EXCEPTION(void)
+{
+ *((volatile int *) 0) = 0;
+}
+
+static void lkdtm_LOOP(void)
+{
+ for (;;)
+ ;
+}
+
+static void lkdtm_EXHAUST_STACK(void)
+{
+ pr_info("Calling function with %lu frame size to depth %d ...\n",
+ REC_STACK_SIZE, recur_count);
+ recursive_loop(recur_count);
+ pr_info("FAIL: survived without exhausting stack?!\n");
+}
+
+static noinline void __lkdtm_CORRUPT_STACK(void *stack)
+{
+ memset(stack, '\xff', 64);
+}
+
+/* This should trip the stack canary, not corrupt the return address. */
+static noinline void lkdtm_CORRUPT_STACK(void)
+{
+ /* Use default char array length that triggers stack protection. */
+ char data[8] __aligned(sizeof(void *));
+
+ pr_info("Corrupting stack containing char array ...\n");
+ __lkdtm_CORRUPT_STACK((void *)&data);
+}
+
+/* Same as above but will only get a canary with -fstack-protector-strong */
+static noinline void lkdtm_CORRUPT_STACK_STRONG(void)
+{
+ union {
+ unsigned short shorts[4];
+ unsigned long *ptr;
+ } data __aligned(sizeof(void *));
+
+ pr_info("Corrupting stack containing union ...\n");
+ __lkdtm_CORRUPT_STACK((void *)&data);
+}
+
+static pid_t stack_pid;
+static unsigned long stack_addr;
+
+static void lkdtm_REPORT_STACK(void)
+{
+ volatile uintptr_t magic;
+ pid_t pid = task_pid_nr(current);
+
+ if (pid != stack_pid) {
+ pr_info("Starting stack offset tracking for pid %d\n", pid);
+ stack_pid = pid;
+ stack_addr = (uintptr_t)&magic;
+ }
+
+ pr_info("Stack offset: %d\n", (int)(stack_addr - (uintptr_t)&magic));
+}
+
+static pid_t stack_canary_pid;
+static unsigned long stack_canary;
+static unsigned long stack_canary_offset;
+
+static noinline void __lkdtm_REPORT_STACK_CANARY(void *stack)
+{
+ int i = 0;
+ pid_t pid = task_pid_nr(current);
+ unsigned long *canary = (unsigned long *)stack;
+ unsigned long current_offset = 0, init_offset = 0;
+
+ /* Do our best to find the canary in a 16 word window ... */
+ for (i = 1; i < 16; i++) {
+ canary = (unsigned long *)stack + i;
+#ifdef CONFIG_STACKPROTECTOR
+ if (*canary == current->stack_canary)
+ current_offset = i;
+ if (*canary == init_task.stack_canary)
+ init_offset = i;
+#endif
+ }
+
+ if (current_offset == 0) {
+ /*
+ * If the canary doesn't match what's in the task_struct,
+ * we're either using a global canary or the stack frame
+ * layout changed.
+ */
+ if (init_offset != 0) {
+ pr_err("FAIL: global stack canary found at offset %ld (canary for pid %d matches init_task's)!\n",
+ init_offset, pid);
+ } else {
+ pr_warn("FAIL: did not correctly locate stack canary :(\n");
+ pr_expected_config(CONFIG_STACKPROTECTOR);
+ }
+
+ return;
+ } else if (init_offset != 0) {
+ pr_warn("WARNING: found both current and init_task canaries nearby?!\n");
+ }
+
+ canary = (unsigned long *)stack + current_offset;
+ if (stack_canary_pid == 0) {
+ stack_canary = *canary;
+ stack_canary_pid = pid;
+ stack_canary_offset = current_offset;
+ pr_info("Recorded stack canary for pid %d at offset %ld\n",
+ stack_canary_pid, stack_canary_offset);
+ } else if (pid == stack_canary_pid) {
+ pr_warn("ERROR: saw pid %d again -- please use a new pid\n", pid);
+ } else {
+ if (current_offset != stack_canary_offset) {
+ pr_warn("ERROR: canary offset changed from %ld to %ld!?\n",
+ stack_canary_offset, current_offset);
+ return;
+ }
+
+ if (*canary == stack_canary) {
+ pr_warn("FAIL: canary identical for pid %d and pid %d at offset %ld!\n",
+ stack_canary_pid, pid, current_offset);
+ } else {
+ pr_info("ok: stack canaries differ between pid %d and pid %d at offset %ld.\n",
+ stack_canary_pid, pid, current_offset);
+ /* Reset the test. */
+ stack_canary_pid = 0;
+ }
+ }
+}
+
+static void lkdtm_REPORT_STACK_CANARY(void)
+{
+ /* Use default char array length that triggers stack protection. */
+ char data[8] __aligned(sizeof(void *)) = { };
+
+ __lkdtm_REPORT_STACK_CANARY((void *)&data);
+}
+
+static void lkdtm_UNALIGNED_LOAD_STORE_WRITE(void)
+{
+ static u8 data[5] __attribute__((aligned(4))) = {1, 2, 3, 4, 5};
+ u32 *p;
+ u32 val = 0x12345678;
+
+ p = (u32 *)(data + 1);
+ if (*p == 0)
+ val = 0x87654321;
+ *p = val;
+
+ if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS))
+ pr_err("XFAIL: arch has CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS\n");
+}
+
+static void lkdtm_SOFTLOCKUP(void)
+{
+ preempt_disable();
+ for (;;)
+ cpu_relax();
+}
+
+static void lkdtm_HARDLOCKUP(void)
+{
+ local_irq_disable();
+ for (;;)
+ cpu_relax();
+}
+
+static void lkdtm_SPINLOCKUP(void)
+{
+ /* Must be called twice to trigger. */
+ spin_lock(&lock_me_up);
+ /* Let sparse know we intended to exit holding the lock. */
+ __release(&lock_me_up);
+}
+
+static void lkdtm_HUNG_TASK(void)
+{
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ schedule();
+}
+
+volatile unsigned int huge = INT_MAX - 2;
+volatile unsigned int ignored;
+
+static void lkdtm_OVERFLOW_SIGNED(void)
+{
+ int value;
+
+ value = huge;
+ pr_info("Normal signed addition ...\n");
+ value += 1;
+ ignored = value;
+
+ pr_info("Overflowing signed addition ...\n");
+ value += 4;
+ ignored = value;
+}
+
+
+static void lkdtm_OVERFLOW_UNSIGNED(void)
+{
+ unsigned int value;
+
+ value = huge;
+ pr_info("Normal unsigned addition ...\n");
+ value += 1;
+ ignored = value;
+
+ pr_info("Overflowing unsigned addition ...\n");
+ value += 4;
+ ignored = value;
+}
+
+/* Intentionally using old-style flex array definition of 1 byte. */
+struct array_bounds_flex_array {
+ int one;
+ int two;
+ char data[1];
+};
+
+struct array_bounds {
+ int one;
+ int two;
+ char data[8];
+ int three;
+};
+
+static void lkdtm_ARRAY_BOUNDS(void)
+{
+ struct array_bounds_flex_array *not_checked;
+ struct array_bounds *checked;
+ volatile int i;
+
+ not_checked = kmalloc(sizeof(*not_checked) * 2, GFP_KERNEL);
+ checked = kmalloc(sizeof(*checked) * 2, GFP_KERNEL);
+ if (!not_checked || !checked) {
+ kfree(not_checked);
+ kfree(checked);
+ return;
+ }
+
+ pr_info("Array access within bounds ...\n");
+ /* For both, touch all bytes in the actual member size. */
+ for (i = 0; i < sizeof(checked->data); i++)
+ checked->data[i] = 'A';
+ /*
+ * For the uninstrumented flex array member, also touch 1 byte
+ * beyond to verify it is correctly uninstrumented.
+ */
+ for (i = 0; i < sizeof(not_checked->data) + 1; i++)
+ not_checked->data[i] = 'A';
+
+ pr_info("Array access beyond bounds ...\n");
+ for (i = 0; i < sizeof(checked->data) + 1; i++)
+ checked->data[i] = 'B';
+
+ kfree(not_checked);
+ kfree(checked);
+ pr_err("FAIL: survived array bounds overflow!\n");
+ if (IS_ENABLED(CONFIG_UBSAN_BOUNDS))
+ pr_expected_config(CONFIG_UBSAN_TRAP);
+ else
+ pr_expected_config(CONFIG_UBSAN_BOUNDS);
+}
+
+static void lkdtm_CORRUPT_LIST_ADD(void)
+{
+ /*
+ * Initially, an empty list via LIST_HEAD:
+ * test_head.next = &test_head
+ * test_head.prev = &test_head
+ */
+ LIST_HEAD(test_head);
+ struct lkdtm_list good, bad;
+ void *target[2] = { };
+ void *redirection = &target;
+
+ pr_info("attempting good list addition\n");
+
+ /*
+ * Adding to the list performs these actions:
+ * test_head.next->prev = &good.node
+ * good.node.next = test_head.next
+ * good.node.prev = test_head
+ * test_head.next = good.node
+ */
+ list_add(&good.node, &test_head);
+
+ pr_info("attempting corrupted list addition\n");
+ /*
+ * In simulating this "write what where" primitive, the "what" is
+ * the address of &bad.node, and the "where" is the address held
+ * by "redirection".
+ */
+ test_head.next = redirection;
+ list_add(&bad.node, &test_head);
+
+ if (target[0] == NULL && target[1] == NULL)
+ pr_err("Overwrite did not happen, but no BUG?!\n");
+ else {
+ pr_err("list_add() corruption not detected!\n");
+ pr_expected_config(CONFIG_DEBUG_LIST);
+ }
+}
+
+static void lkdtm_CORRUPT_LIST_DEL(void)
+{
+ LIST_HEAD(test_head);
+ struct lkdtm_list item;
+ void *target[2] = { };
+ void *redirection = &target;
+
+ list_add(&item.node, &test_head);
+
+ pr_info("attempting good list removal\n");
+ list_del(&item.node);
+
+ pr_info("attempting corrupted list removal\n");
+ list_add(&item.node, &test_head);
+
+ /* As with the list_add() test above, this corrupts "next". */
+ item.node.next = redirection;
+ list_del(&item.node);
+
+ if (target[0] == NULL && target[1] == NULL)
+ pr_err("Overwrite did not happen, but no BUG?!\n");
+ else {
+ pr_err("list_del() corruption not detected!\n");
+ pr_expected_config(CONFIG_DEBUG_LIST);
+ }
+}
+
+/* Test that VMAP_STACK is actually allocating with a leading guard page */
+static void lkdtm_STACK_GUARD_PAGE_LEADING(void)
+{
+ const unsigned char *stack = task_stack_page(current);
+ const unsigned char *ptr = stack - 1;
+ volatile unsigned char byte;
+
+ pr_info("attempting bad read from page below current stack\n");
+
+ byte = *ptr;
+
+ pr_err("FAIL: accessed page before stack! (byte: %x)\n", byte);
+}
+
+/* Test that VMAP_STACK is actually allocating with a trailing guard page */
+static void lkdtm_STACK_GUARD_PAGE_TRAILING(void)
+{
+ const unsigned char *stack = task_stack_page(current);
+ const unsigned char *ptr = stack + THREAD_SIZE;
+ volatile unsigned char byte;
+
+ pr_info("attempting bad read from page above current stack\n");
+
+ byte = *ptr;
+
+ pr_err("FAIL: accessed page after stack! (byte: %x)\n", byte);
+}
+
+static void lkdtm_UNSET_SMEP(void)
+{
+#if IS_ENABLED(CONFIG_X86_64) && !IS_ENABLED(CONFIG_UML)
+#define MOV_CR4_DEPTH 64
+ void (*direct_write_cr4)(unsigned long val);
+ unsigned char *insn;
+ unsigned long cr4;
+ int i;
+
+ cr4 = native_read_cr4();
+
+ if ((cr4 & X86_CR4_SMEP) != X86_CR4_SMEP) {
+ pr_err("FAIL: SMEP not in use\n");
+ return;
+ }
+ cr4 &= ~(X86_CR4_SMEP);
+
+ pr_info("trying to clear SMEP normally\n");
+ native_write_cr4(cr4);
+ if (cr4 == native_read_cr4()) {
+ pr_err("FAIL: pinning SMEP failed!\n");
+ cr4 |= X86_CR4_SMEP;
+ pr_info("restoring SMEP\n");
+ native_write_cr4(cr4);
+ return;
+ }
+ pr_info("ok: SMEP did not get cleared\n");
+
+ /*
+ * To test the post-write pinning verification we need to call
+ * directly into the middle of native_write_cr4() where the
+ * cr4 write happens, skipping any pinning. This searches for
+ * the cr4 writing instruction.
+ */
+ insn = (unsigned char *)native_write_cr4;
+ for (i = 0; i < MOV_CR4_DEPTH; i++) {
+ /* mov %rdi, %cr4 */
+ if (insn[i] == 0x0f && insn[i+1] == 0x22 && insn[i+2] == 0xe7)
+ break;
+ /* mov %rdi,%rax; mov %rax, %cr4 */
+ if (insn[i] == 0x48 && insn[i+1] == 0x89 &&
+ insn[i+2] == 0xf8 && insn[i+3] == 0x0f &&
+ insn[i+4] == 0x22 && insn[i+5] == 0xe0)
+ break;
+ }
+ if (i >= MOV_CR4_DEPTH) {
+ pr_info("ok: cannot locate cr4 writing call gadget\n");
+ return;
+ }
+ direct_write_cr4 = (void *)(insn + i);
+
+ pr_info("trying to clear SMEP with call gadget\n");
+ direct_write_cr4(cr4);
+ if (native_read_cr4() & X86_CR4_SMEP) {
+ pr_info("ok: SMEP removal was reverted\n");
+ } else {
+ pr_err("FAIL: cleared SMEP not detected!\n");
+ cr4 |= X86_CR4_SMEP;
+ pr_info("restoring SMEP\n");
+ native_write_cr4(cr4);
+ }
+#else
+ pr_err("XFAIL: this test is x86_64-only\n");
+#endif
+}
+
+static void lkdtm_DOUBLE_FAULT(void)
+{
+#if IS_ENABLED(CONFIG_X86_32) && !IS_ENABLED(CONFIG_UML)
+ /*
+ * Trigger #DF by setting the stack limit to zero. This clobbers
+ * a GDT TLS slot, which is okay because the current task will die
+ * anyway due to the double fault.
+ */
+ struct desc_struct d = {
+ .type = 3, /* expand-up, writable, accessed data */
+ .p = 1, /* present */
+ .d = 1, /* 32-bit */
+ .g = 0, /* limit in bytes */
+ .s = 1, /* not system */
+ };
+
+ local_irq_disable();
+ write_gdt_entry(get_cpu_gdt_rw(smp_processor_id()),
+ GDT_ENTRY_TLS_MIN, &d, DESCTYPE_S);
+
+ /*
+ * Put our zero-limit segment in SS and then trigger a fault. The
+ * 4-byte access to (%esp) will fault with #SS, and the attempt to
+ * deliver the fault will recursively cause #SS and result in #DF.
+ * This whole process happens while NMIs and MCEs are blocked by the
+ * MOV SS window. This is nice because an NMI with an invalid SS
+ * would also double-fault, resulting in the NMI or MCE being lost.
+ */
+ asm volatile ("movw %0, %%ss; addl $0, (%%esp)" ::
+ "r" ((unsigned short)(GDT_ENTRY_TLS_MIN << 3)));
+
+ pr_err("FAIL: tried to double fault but didn't die\n");
+#else
+ pr_err("XFAIL: this test is ia32-only\n");
+#endif
+}
+
+#ifdef CONFIG_ARM64
+static noinline void change_pac_parameters(void)
+{
+ if (IS_ENABLED(CONFIG_ARM64_PTR_AUTH_KERNEL)) {
+ /* Reset the keys of current task */
+ ptrauth_thread_init_kernel(current);
+ ptrauth_thread_switch_kernel(current);
+ }
+}
+#endif
+
+static noinline void lkdtm_CORRUPT_PAC(void)
+{
+#ifdef CONFIG_ARM64
+#define CORRUPT_PAC_ITERATE 10
+ int i;
+
+ if (!IS_ENABLED(CONFIG_ARM64_PTR_AUTH_KERNEL))
+ pr_err("FAIL: kernel not built with CONFIG_ARM64_PTR_AUTH_KERNEL\n");
+
+ if (!system_supports_address_auth()) {
+ pr_err("FAIL: CPU lacks pointer authentication feature\n");
+ return;
+ }
+
+ pr_info("changing PAC parameters to force function return failure...\n");
+ /*
+ * PAC is a hash value computed from input keys, return address and
+ * stack pointer. As pac has fewer bits so there is a chance of
+ * collision, so iterate few times to reduce the collision probability.
+ */
+ for (i = 0; i < CORRUPT_PAC_ITERATE; i++)
+ change_pac_parameters();
+
+ pr_err("FAIL: survived PAC changes! Kernel may be unstable from here\n");
+#else
+ pr_err("XFAIL: this test is arm64-only\n");
+#endif
+}
+
+static struct crashtype crashtypes[] = {
+ CRASHTYPE(PANIC),
+ CRASHTYPE(BUG),
+ CRASHTYPE(WARNING),
+ CRASHTYPE(WARNING_MESSAGE),
+ CRASHTYPE(EXCEPTION),
+ CRASHTYPE(LOOP),
+ CRASHTYPE(EXHAUST_STACK),
+ CRASHTYPE(CORRUPT_STACK),
+ CRASHTYPE(CORRUPT_STACK_STRONG),
+ CRASHTYPE(REPORT_STACK),
+ CRASHTYPE(REPORT_STACK_CANARY),
+ CRASHTYPE(UNALIGNED_LOAD_STORE_WRITE),
+ CRASHTYPE(SOFTLOCKUP),
+ CRASHTYPE(HARDLOCKUP),
+ CRASHTYPE(SPINLOCKUP),
+ CRASHTYPE(HUNG_TASK),
+ CRASHTYPE(OVERFLOW_SIGNED),
+ CRASHTYPE(OVERFLOW_UNSIGNED),
+ CRASHTYPE(ARRAY_BOUNDS),
+ CRASHTYPE(CORRUPT_LIST_ADD),
+ CRASHTYPE(CORRUPT_LIST_DEL),
+ CRASHTYPE(STACK_GUARD_PAGE_LEADING),
+ CRASHTYPE(STACK_GUARD_PAGE_TRAILING),
+ CRASHTYPE(UNSET_SMEP),
+ CRASHTYPE(DOUBLE_FAULT),
+ CRASHTYPE(CORRUPT_PAC),
+};
+
+struct crashtype_category bugs_crashtypes = {
+ .crashtypes = crashtypes,
+ .len = ARRAY_SIZE(crashtypes),
+};