| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Kees Cook | 886 | 78.48% | 18 | 56.25% |
| Christophe Leroy | 214 | 18.95% | 6 | 18.75% |
| Catalin Marinas | 17 | 1.51% | 1 | 3.12% |
| Ankita Garg | 3 | 0.27% | 1 | 3.12% |
| Dan Aloni | 3 | 0.27% | 1 | 3.12% |
| Linus Torvalds (pre-git) | 2 | 0.18% | 1 | 3.12% |
| Linus Torvalds | 1 | 0.09% | 1 | 3.12% |
| Greg Kroah-Hartman | 1 | 0.09% | 1 | 3.12% |
| David Windsor | 1 | 0.09% | 1 | 3.12% |
| Arnd Bergmann | 1 | 0.09% | 1 | 3.12% |
| Total | 1129 | 32 |
// SPDX-License-Identifier: GPL-2.0 /* * This is for all the tests related to validating kernel memory * permissions: non-executable regions, non-writable regions, and * even non-readable regions. */ #include "lkdtm.h" #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/mman.h> #include <linux/uaccess.h> #include <asm/cacheflush.h> #include <asm/sections.h> /* Whether or not to fill the target memory area with do_nothing(). */ #define CODE_WRITE true #define CODE_AS_IS false /* How many bytes to copy to be sure we've copied enough of do_nothing(). */ #define EXEC_SIZE 64 /* This is non-const, so it will end up in the .data section. */ static u8 data_area[EXEC_SIZE]; /* This is const, so it will end up in the .rodata section. */ static const unsigned long rodata = 0xAA55AA55; /* This is marked __ro_after_init, so it should ultimately be .rodata. */ static unsigned long ro_after_init __ro_after_init = 0x55AA5500; /* * This just returns to the caller. It is designed to be copied into * non-executable memory regions. */ static noinline void do_nothing(void) { return; } /* Must immediately follow do_nothing for size calculuations to work out. */ static noinline void do_overwritten(void) { pr_info("do_overwritten wasn't overwritten!\n"); return; } static noinline void do_almost_nothing(void) { pr_info("do_nothing was hijacked!\n"); } static void *setup_function_descriptor(func_desc_t *fdesc, void *dst) { if (!have_function_descriptors()) return dst; memcpy(fdesc, do_nothing, sizeof(*fdesc)); fdesc->addr = (unsigned long)dst; barrier(); return fdesc; } static noinline __nocfi void execute_location(void *dst, bool write) { void (*func)(void); func_desc_t fdesc; void *do_nothing_text = dereference_function_descriptor(do_nothing); pr_info("attempting ok execution at %px\n", do_nothing_text); do_nothing(); if (write == CODE_WRITE) { memcpy(dst, do_nothing_text, EXEC_SIZE); flush_icache_range((unsigned long)dst, (unsigned long)dst + EXEC_SIZE); } pr_info("attempting bad execution at %px\n", dst); func = setup_function_descriptor(&fdesc, dst); func(); pr_err("FAIL: func returned\n"); } static void execute_user_location(void *dst) { int copied; /* Intentionally crossing kernel/user memory boundary. */ void (*func)(void); func_desc_t fdesc; void *do_nothing_text = dereference_function_descriptor(do_nothing); pr_info("attempting ok execution at %px\n", do_nothing_text); do_nothing(); copied = access_process_vm(current, (unsigned long)dst, do_nothing_text, EXEC_SIZE, FOLL_WRITE); if (copied < EXEC_SIZE) return; pr_info("attempting bad execution at %px\n", dst); func = setup_function_descriptor(&fdesc, dst); func(); pr_err("FAIL: func returned\n"); } static void lkdtm_WRITE_RO(void) { /* Explicitly cast away "const" for the test and make volatile. */ volatile unsigned long *ptr = (unsigned long *)&rodata; pr_info("attempting bad rodata write at %px\n", ptr); *ptr ^= 0xabcd1234; pr_err("FAIL: survived bad write\n"); } static void lkdtm_WRITE_RO_AFTER_INIT(void) { volatile unsigned long *ptr = &ro_after_init; /* * Verify we were written to during init. Since an Oops * is considered a "success", a failure is to just skip the * real test. */ if ((*ptr & 0xAA) != 0xAA) { pr_info("%p was NOT written during init!?\n", ptr); return; } pr_info("attempting bad ro_after_init write at %px\n", ptr); *ptr ^= 0xabcd1234; pr_err("FAIL: survived bad write\n"); } static void lkdtm_WRITE_KERN(void) { size_t size; volatile unsigned char *ptr; size = (unsigned long)dereference_function_descriptor(do_overwritten) - (unsigned long)dereference_function_descriptor(do_nothing); ptr = dereference_function_descriptor(do_overwritten); pr_info("attempting bad %zu byte write at %px\n", size, ptr); memcpy((void *)ptr, (unsigned char *)do_nothing, size); flush_icache_range((unsigned long)ptr, (unsigned long)(ptr + size)); pr_err("FAIL: survived bad write\n"); do_overwritten(); } static void lkdtm_WRITE_OPD(void) { size_t size = sizeof(func_desc_t); void (*func)(void) = do_nothing; if (!have_function_descriptors()) { pr_info("XFAIL: Platform doesn't use function descriptors.\n"); return; } pr_info("attempting bad %zu bytes write at %px\n", size, do_nothing); memcpy(do_nothing, do_almost_nothing, size); pr_err("FAIL: survived bad write\n"); asm("" : "=m"(func)); func(); } static void lkdtm_EXEC_DATA(void) { execute_location(data_area, CODE_WRITE); } static void lkdtm_EXEC_STACK(void) { u8 stack_area[EXEC_SIZE]; execute_location(stack_area, CODE_WRITE); } static void lkdtm_EXEC_KMALLOC(void) { u32 *kmalloc_area = kmalloc(EXEC_SIZE, GFP_KERNEL); execute_location(kmalloc_area, CODE_WRITE); kfree(kmalloc_area); } static void lkdtm_EXEC_VMALLOC(void) { u32 *vmalloc_area = vmalloc(EXEC_SIZE); execute_location(vmalloc_area, CODE_WRITE); vfree(vmalloc_area); } static void lkdtm_EXEC_RODATA(void) { execute_location(dereference_function_descriptor(lkdtm_rodata_do_nothing), CODE_AS_IS); } static void lkdtm_EXEC_USERSPACE(void) { unsigned long user_addr; user_addr = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS | MAP_PRIVATE, 0); if (user_addr >= TASK_SIZE) { pr_warn("Failed to allocate user memory\n"); return; } execute_user_location((void *)user_addr); vm_munmap(user_addr, PAGE_SIZE); } static void lkdtm_EXEC_NULL(void) { execute_location(NULL, CODE_AS_IS); } static void lkdtm_ACCESS_USERSPACE(void) { unsigned long user_addr, tmp = 0; unsigned long *ptr; user_addr = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS | MAP_PRIVATE, 0); if (user_addr >= TASK_SIZE) { pr_warn("Failed to allocate user memory\n"); return; } if (copy_to_user((void __user *)user_addr, &tmp, sizeof(tmp))) { pr_warn("copy_to_user failed\n"); vm_munmap(user_addr, PAGE_SIZE); return; } ptr = (unsigned long *)user_addr; pr_info("attempting bad read at %px\n", ptr); tmp = *ptr; tmp += 0xc0dec0de; pr_err("FAIL: survived bad read\n"); pr_info("attempting bad write at %px\n", ptr); *ptr = tmp; pr_err("FAIL: survived bad write\n"); vm_munmap(user_addr, PAGE_SIZE); } static void lkdtm_ACCESS_NULL(void) { unsigned long tmp; volatile unsigned long *ptr = (unsigned long *)NULL; pr_info("attempting bad read at %px\n", ptr); tmp = *ptr; tmp += 0xc0dec0de; pr_err("FAIL: survived bad read\n"); pr_info("attempting bad write at %px\n", ptr); *ptr = tmp; pr_err("FAIL: survived bad write\n"); } void __init lkdtm_perms_init(void) { /* Make sure we can write to __ro_after_init values during __init */ ro_after_init |= 0xAA; } static struct crashtype crashtypes[] = { CRASHTYPE(WRITE_RO), CRASHTYPE(WRITE_RO_AFTER_INIT), CRASHTYPE(WRITE_KERN), CRASHTYPE(WRITE_OPD), CRASHTYPE(EXEC_DATA), CRASHTYPE(EXEC_STACK), CRASHTYPE(EXEC_KMALLOC), CRASHTYPE(EXEC_VMALLOC), CRASHTYPE(EXEC_RODATA), CRASHTYPE(EXEC_USERSPACE), CRASHTYPE(EXEC_NULL), CRASHTYPE(ACCESS_USERSPACE), CRASHTYPE(ACCESS_NULL), }; struct crashtype_category perms_crashtypes = { .crashtypes = crashtypes, .len = ARRAY_SIZE(crashtypes), };
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