Tests: Add LibELF tests

Tests/CMakeLists.txt

@@ -3,6 +3,7 @@ add_subdirectory(Kernel)
 add_subdirectory(LibC)
 add_subdirectory(LibCore)
 add_subdirectory(LibCompress)
+add_subdirectory(LibELF)
 add_subdirectory(LibGfx)
 add_subdirectory(LibJS)
 add_subdirectory(LibM)

Tests/LibELF/CMakeLists.txt

@@ -0,0 +1,5 @@
+file(GLOB CMD_SOURCES CONFIGURE_DEPENDS "*.cpp")
+
+foreach(CMD_SRC ${CMD_SOURCES})
+ serenity_test(${CMD_SRC} LibELF)
+endforeach()

Tests/LibELF/test-elf.cpp

@@ -0,0 +1,291 @@
+/*
+ * Copyright (c) 2021, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibC/elf.h>
+#include <LibCore/File.h>
+#include <LibTest/TestCase.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+TEST_CASE(test_interp_header_tiny_p_filesz)
+{
+ char buffer[0x2000];
+
+ auto& header = *(Elf32_Ehdr*)buffer;
+ header.e_ident[EI_MAG0] = ELFMAG0;
+ header.e_ident[EI_MAG1] = ELFMAG1;
+ header.e_ident[EI_MAG2] = ELFMAG2;
+ header.e_ident[EI_MAG3] = ELFMAG3;
+ header.e_ident[EI_CLASS] = ELFCLASS32;
+ header.e_ident[EI_DATA] = ELFDATA2LSB;
+ header.e_ident[EI_VERSION] = EV_CURRENT;
+ header.e_ident[EI_OSABI] = ELFOSABI_SYSV;
+ header.e_ident[EI_ABIVERSION] = 0;
+ header.e_type = ET_REL;
+ header.e_version = EV_CURRENT;
+ header.e_ehsize = sizeof(Elf32_Ehdr);
+ header.e_machine = EM_386;
+ header.e_shentsize = sizeof(Elf32_Shdr);
+ header.e_phnum = 1;
+ header.e_phoff = 52; // inaccurate
+ header.e_phentsize = sizeof(Elf32_Phdr); // inaccurate
+ header.e_shnum = 3; // inaccurate
+ header.e_shoff = 1024; // inaccurate
+ header.e_shstrndx = 2; // inaccurate
+ header.e_entry = 1024; // inaccurate
+
+ auto* ph = (Elf32_Phdr*)(&buffer[header.e_phoff]);
+ ph[0].p_flags = PF_R | PF_X;
+ ph[0].p_vaddr = 0x00d4;
+ ph[0].p_align = PAGE_SIZE;
+ ph[0].p_type = PT_INTERP;
+ ph[0].p_memsz = 0xffff0000;
+ ph[0].p_offset = 0x100;
+
+ // p_filesz (1 or less) to trigger crash
+ ph[0].p_filesz = 1;
+
+ char path[] = "/tmp/test-elf.XXXXXX";
+ auto fd = mkstemp(path);
+ EXPECT_NE(fd, -1);
+ EXPECT_EQ(fchmod(fd, 0700), 0);
+
+ int nwritten = write(fd, buffer, sizeof(buffer));
+ EXPECT(nwritten);
+
+ auto elf_path = Core::File::read_link(String::formatted("/proc/{}/fd/{}", getpid(), fd));
+ EXPECT(elf_path.characters());
+
+ int rc = execl(elf_path.characters(), "test-elf", nullptr);
+ EXPECT_EQ(rc, -1);
+ EXPECT_EQ(errno, 8);
+
+ EXPECT_EQ(unlink(path), 0);
+}
+
+TEST_CASE(test_interp_header_p_filesz_larger_than_p_memsz)
+{
+ char buffer[0x2000];
+
+ auto& header = *(Elf32_Ehdr*)buffer;
+ header.e_ident[EI_MAG0] = ELFMAG0;
+ header.e_ident[EI_MAG1] = ELFMAG1;
+ header.e_ident[EI_MAG2] = ELFMAG2;
+ header.e_ident[EI_MAG3] = ELFMAG3;
+ header.e_ident[EI_CLASS] = ELFCLASS32;
+ header.e_ident[EI_DATA] = ELFDATA2LSB;
+ header.e_ident[EI_VERSION] = EV_CURRENT;
+ header.e_ident[EI_OSABI] = ELFOSABI_SYSV;
+ header.e_ident[EI_ABIVERSION] = 0;
+ header.e_type = ET_REL;
+ header.e_version = EV_CURRENT;
+ header.e_ehsize = sizeof(Elf32_Ehdr);
+ header.e_machine = EM_386;
+ header.e_shentsize = sizeof(Elf32_Shdr);
+ header.e_phnum = 1;
+ header.e_phoff = 52; // inaccurate
+ header.e_phentsize = sizeof(Elf32_Phdr); // inaccurate
+ header.e_shnum = 3; // inaccurate
+ header.e_shoff = 1024; // inaccurate
+ header.e_shstrndx = 2; // inaccurate
+ header.e_entry = 1024; // inaccurate
+
+ auto* ph = (Elf32_Phdr*)(&buffer[header.e_phoff]);
+ ph[0].p_flags = PF_R | PF_X;
+ ph[0].p_vaddr = 0x00d4;
+ ph[0].p_align = PAGE_SIZE;
+ ph[0].p_type = PT_INTERP;
+ ph[0].p_memsz = 0xffff0000;
+ ph[0].p_offset = 0x1000;
+ ph[0].p_filesz = 0x1000;
+
+ char path[] = "/tmp/test-elf.XXXXXX";
+ auto fd = mkstemp(path);
+ EXPECT_NE(fd, -1);
+ EXPECT_EQ(fchmod(fd, 0700), 0);
+
+ int nwritten = write(fd, buffer, sizeof(buffer));
+ EXPECT(nwritten);
+
+ auto elf_path = Core::File::read_link(String::formatted("/proc/{}/fd/{}", getpid(), fd));
+ EXPECT(elf_path.characters());
+
+ int rc = execl(elf_path.characters(), "test-elf", nullptr);
+ EXPECT_EQ(rc, -1);
+ EXPECT_EQ(errno, 8);
+
+ EXPECT_EQ(unlink(path), 0);
+}
+
+TEST_CASE(test_interp_header_p_filesz_plus_p_offset_overflow_p_memsz)
+{
+ char buffer[0x2000];
+
+ auto& header = *(Elf32_Ehdr*)buffer;
+ header.e_ident[EI_MAG0] = ELFMAG0;
+ header.e_ident[EI_MAG1] = ELFMAG1;
+ header.e_ident[EI_MAG2] = ELFMAG2;
+ header.e_ident[EI_MAG3] = ELFMAG3;
+ header.e_ident[EI_CLASS] = ELFCLASS32;
+ header.e_ident[EI_DATA] = ELFDATA2LSB;
+ header.e_ident[EI_VERSION] = EV_CURRENT;
+ header.e_ident[EI_OSABI] = ELFOSABI_SYSV;
+ header.e_ident[EI_ABIVERSION] = 0;
+ header.e_type = ET_REL;
+ header.e_version = EV_CURRENT;
+ header.e_ehsize = sizeof(Elf32_Ehdr);
+ header.e_machine = EM_386;
+ header.e_shentsize = sizeof(Elf32_Shdr);
+ header.e_phoff = 52; // inaccurate
+ header.e_phentsize = sizeof(Elf32_Phdr); // inaccurate
+ header.e_shnum = 3; // inaccurate
+ header.e_shoff = 1024; // inaccurate
+ header.e_shstrndx = 2; // inaccurate
+ header.e_entry = 1024; // inaccurate
+
+ auto* ph = (Elf32_Phdr*)(&buffer[header.e_phoff]);
+ ph[0].p_flags = PF_R | PF_X;
+ ph[0].p_vaddr = 0x00d4;
+ ph[0].p_align = PAGE_SIZE;
+ ph[0].p_type = PT_INTERP;
+
+ // p_memsz must be of sufficient size to hold maxint - 0x1000
+ ph[0].p_memsz = 0xfffff000;
+
+ // p_offset + p_filesz must not exceed buffer size in order to pass buffer size check in ELF::validate_program_headers().
+ // p_memsz + p_offset must be sufficiently large to overflow maxint.
+ ph[0].p_offset = 0x1234;
+ ph[0].p_filesz = -0x1000;
+
+ char path[] = "/tmp/test-elf.XXXXXX";
+ auto fd = mkstemp(path);
+ EXPECT_NE(fd, -1);
+ EXPECT_EQ(fchmod(fd, 0700), 0);
+
+ int nwritten = write(fd, buffer, sizeof(buffer));
+ EXPECT(nwritten);
+
+ auto elf_path = Core::File::read_link(String::formatted("/proc/{}/fd/{}", getpid(), fd));
+ EXPECT(elf_path.characters());
+
+ int rc = execl(elf_path.characters(), "test-elf", nullptr);
+ EXPECT_EQ(rc, -1);
+ EXPECT_EQ(errno, 8);
+
+ EXPECT_EQ(unlink(path), 0);
+}
+
+TEST_CASE(test_load_header_p_memsz_zero)
+{
+ char buffer[0x2000];
+
+ auto& header = *(Elf32_Ehdr*)buffer;
+ header.e_ident[EI_MAG0] = ELFMAG0;
+ header.e_ident[EI_MAG1] = ELFMAG1;
+ header.e_ident[EI_MAG2] = ELFMAG2;
+ header.e_ident[EI_MAG3] = ELFMAG3;
+ header.e_ident[EI_CLASS] = ELFCLASS32;
+ header.e_ident[EI_DATA] = ELFDATA2LSB;
+ header.e_ident[EI_VERSION] = EV_CURRENT;
+ header.e_ident[EI_OSABI] = ELFOSABI_SYSV;
+ header.e_ident[EI_ABIVERSION] = 0;
+ header.e_type = ET_REL;
+ header.e_version = EV_CURRENT;
+ header.e_ehsize = sizeof(Elf32_Ehdr);
+ header.e_machine = EM_386;
+ header.e_shentsize = sizeof(Elf32_Shdr);
+ header.e_phoff = 52; // inaccurate
+ header.e_phentsize = sizeof(Elf32_Phdr); // inaccurate
+ header.e_shnum = 3; // inaccurate
+ header.e_shoff = 1024; // inaccurate
+ header.e_shstrndx = 2; // inaccurate
+ header.e_entry = 1024; // inaccurate
+
+ auto* ph = (Elf32_Phdr*)(&buffer[header.e_phoff]);
+ ph[0].p_flags = PF_R | PF_X;
+ ph[0].p_vaddr = 0x00d4;
+ ph[0].p_align = PAGE_SIZE;
+ ph[0].p_type = PT_LOAD;
+ ph[0].p_offset = 0;
+ ph[0].p_filesz = 0;
+
+ // p_memsz zero to trigger crash
+ ph[0].p_memsz = 0;
+
+ char path[] = "/tmp/test-elf.XXXXXX";
+ auto fd = mkstemp(path);
+ EXPECT_NE(fd, -1);
+ EXPECT_EQ(fchmod(fd, 0700), 0);
+
+ int nwritten = write(fd, buffer, sizeof(buffer));
+ EXPECT(nwritten);
+
+ auto elf_path = Core::File::read_link(String::formatted("/proc/{}/fd/{}", getpid(), fd));
+ EXPECT(elf_path.characters());
+
+ int rc = execl(elf_path.characters(), "test-elf", nullptr);
+ EXPECT_EQ(rc, -1);
+ EXPECT_EQ(errno, 8);
+
+ EXPECT_EQ(unlink(path), 0);
+}
+
+TEST_CASE(test_load_header_p_memsz_not_equal_to_p_align)
+{
+ char buffer[0x2000];
+
+ auto& header = *(Elf32_Ehdr*)buffer;
+ header.e_ident[EI_MAG0] = ELFMAG0;
+ header.e_ident[EI_MAG1] = ELFMAG1;
+ header.e_ident[EI_MAG2] = ELFMAG2;
+ header.e_ident[EI_MAG3] = ELFMAG3;
+ header.e_ident[EI_CLASS] = ELFCLASS32;
+ header.e_ident[EI_DATA] = ELFDATA2LSB;
+ header.e_ident[EI_VERSION] = EV_CURRENT;
+ header.e_ident[EI_OSABI] = ELFOSABI_SYSV;
+ header.e_ident[EI_ABIVERSION] = 0;
+ header.e_type = ET_REL;
+ header.e_version = EV_CURRENT;
+ header.e_ehsize = sizeof(Elf32_Ehdr);
+ header.e_machine = EM_386;
+ header.e_shentsize = sizeof(Elf32_Shdr);
+ header.e_phoff = 52; // inaccurate
+ header.e_phentsize = sizeof(Elf32_Phdr); // inaccurate
+ header.e_shnum = 3; // inaccurate
+ header.e_shoff = 1024; // inaccurate
+ header.e_shstrndx = 2; // inaccurate
+ header.e_entry = 1024; // inaccurate
+
+ auto* ph = (Elf32_Phdr*)(&buffer[header.e_phoff]);
+ ph[0].p_flags = PF_R | PF_X;
+ ph[0].p_vaddr = 0x00d4;
+ ph[0].p_type = PT_LOAD;
+ ph[0].p_memsz = 0xffff0000;
+ ph[0].p_offset = 0x1000;
+ ph[0].p_filesz = 0x1000;
+
+ // p_align not equal to PAGE_SIZE to trigger crash
+ ph[0].p_align = PAGE_SIZE / 2;
+
+ char path[] = "/tmp/test-elf.XXXXXX";
+ auto fd = mkstemp(path);
+ EXPECT_NE(fd, -1);
+ EXPECT_EQ(fchmod(fd, 0700), 0);
+
+ int nwritten = write(fd, buffer, sizeof(buffer));
+ EXPECT(nwritten);
+
+ auto elf_path = Core::File::read_link(String::formatted("/proc/{}/fd/{}", getpid(), fd));
+ EXPECT(elf_path.characters());
+
+ int rc = execl(elf_path.characters(), "test-elf", nullptr);
+ EXPECT_EQ(rc, -1);
+ EXPECT_EQ(errno, 8);
+
+ EXPECT_EQ(unlink(path), 0);
+}