]> git.ipfire.org Git - pakfire.git/commitdiff
linter: Move CF protection check
authorMichael Tremer <michael.tremer@ipfire.org>
Sat, 26 Oct 2024 12:02:34 +0000 (12:02 +0000)
committerMichael Tremer <michael.tremer@ipfire.org>
Sat, 26 Oct 2024 12:02:34 +0000 (12:02 +0000)
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
src/libpakfire/file.c
src/libpakfire/linter-file.c

index faabd18013a287b3a0e5c0f3843f6fa62c4db819..23da7dc81f8fc0729767480a5d9c25713aa47aa1 100644 (file)
@@ -1839,45 +1839,6 @@ ERROR:
        return r;
 }
 
-typedef int (*__pakfire_file_for_elf_section_callback)(
-       struct pakfire_file* file,
-       Elf* elf,
-       const Elf_Scn* section,
-       const GElf_Shdr* shdr,
-       Elf_Data* data);
-
-static int pakfire_file_for_elf_section(struct pakfire_file* file,
-               Elf* elf, const Elf64_Word type, __pakfire_file_for_elf_section_callback callback) {
-       Elf_Scn* section = NULL;
-       GElf_Shdr shdr;
-       Elf_Data* data;
-       int r = -EINVAL;
-
-       // Walk through all sections
-       for (;;) {
-               section = elf_nextscn(elf, section);
-               if (!section)
-                       break;
-
-               // Fetch the section header
-               gelf_getshdr(section, &shdr);
-
-               // Skip sections that don't match
-               if (type && shdr.sh_type != type)
-                       continue;
-
-               // Fetch the data
-               data = elf_getdata(section, NULL);
-
-               // Call the callback
-               r = callback(file, elf, section, &shdr, data);
-               if (r)
-                       break;
-       }
-
-       return r;
-}
-
 static int pakfire_file_get_elf_section(struct pakfire_file* file,
                Elf* elf, const Elf64_Word type, Elf_Scn** section, GElf_Shdr* header, Elf_Data** data) {
        Elf_Scn* s = NULL;
@@ -1940,38 +1901,6 @@ static int pakfire_file_get_elf_type(struct pakfire_file* file) {
        return type;
 }
 
-static int pakfire_file_elf_dyn_walk(struct pakfire_file* file, Elf* elf,
-               int (*callback)(struct pakfire_file* file,
-                       Elf* elf, const GElf_Shdr* shdr, const GElf_Dyn* dyn, void* data),
-               void* data) {
-       Elf_Scn* dynamic = NULL;
-       GElf_Shdr shdr;
-       Elf_Data* elf_data = NULL;
-       GElf_Dyn dyn;
-       int r;
-
-       // Find the dynamic linking information
-       r = pakfire_file_get_elf_section(file, elf, SHT_DYNAMIC, &dynamic, &shdr, &elf_data);
-       if (r) {
-               DEBUG(file->ctx, "%s does not have a dynamic section\n", pakfire_file_get_path(file));
-               return 0;
-       }
-
-       // Walk through all entries...
-       for (unsigned int i = 0; ; i++)  {
-               // Fetch the next entry
-               if (!gelf_getdyn(elf_data, i, &dyn))
-                       break;
-
-               // Call the callback
-               r = callback(file, elf, &shdr, &dyn, data);
-               if (r)
-                       return r;
-       }
-
-       return 0;
-}
-
 static int __pakfire_file_check_debuginfo(struct pakfire_file* file, Elf* elf, void* data) {
        Elf_Scn* symtab = NULL;
        int r;
@@ -2320,169 +2249,6 @@ static int pakfire_file_check_capabilities(struct pakfire_file* file) {
        return 0;
 }
 
-static uint32_t read_4_bytes(const int endianess, const char* data) {
-       uint32_t bytes = 0;
-
-       switch (endianess) {
-               // Litte Endian
-               case ELFDATA2LSB:
-                       bytes = data[0] |
-                               ((uint32_t)data[1] << 8) |
-                               ((uint32_t)data[2] << 16) |
-                               ((uint32_t)data[3] << 24);
-                       break;
-
-               // Big endian
-               case ELFDATA2MSB:
-                       bytes = data[3] |
-                               ((uint32_t)data[2] << 8) |
-                               ((uint32_t)data[1] << 16) |
-                               ((uint32_t)data[0] << 24);
-                       break;
-       }
-
-       return bytes;
-}
-
-static int __pakfire_file_check_cf_protection_x86(struct pakfire_file* file,
-               const int endianess, const uint32_t type, const char* payload) {
-       switch (type) {
-               case GNU_PROPERTY_X86_FEATURE_1_AND:
-                       break;
-
-               // XXX what should we do in this case? Just ignore?
-               default:
-                       return 0;
-       }
-
-       uint32_t property = read_4_bytes(endianess, payload);
-
-       // Check for IBT
-       if (!(property & GNU_PROPERTY_X86_FEATURE_1_IBT)) {
-               DEBUG(file->ctx, "%s: IBT property is not enabled\n",
-                       pakfire_file_get_path(file));
-
-               // XXX TODO Actually modify any flags
-
-               return 0;
-       }
-
-       // Check for Shadow Stack
-       if (!(property & GNU_PROPERTY_X86_FEATURE_1_SHSTK)) {
-               DEBUG(file->ctx, "%s: Shadow Stack is not enabled\n",
-                       pakfire_file_get_path(file));
-
-               // XXX TODO Actually modify any flags
-
-               return 0;
-       }
-
-       return 0;
-}
-
-static int __pakfire_file_check_cf_protection_aarch64(struct pakfire_file* file,
-               const int endianess, const uint32_t type, const char* payload) {
-       # warning TODO
-       return 0;
-}
-
-static int pakfire_file_check_cf_protection_callback(struct pakfire_file* file,
-               Elf* elf, const Elf_Scn* section, const GElf_Shdr* shdr, Elf_Data* data) {
-       GElf_Ehdr ehdr = {};
-       GElf_Nhdr nhdr = {};
-       size_t offset = 0;
-       size_t offset_name = 0;
-       size_t offset_data = 0;
-       int r;
-
-       // Fetch the ELF header
-       if (!gelf_getehdr(elf, &ehdr)) {
-               ERROR(file->ctx, "Could not fetch the ELF header for %s: %m\n",
-                       pakfire_file_get_path(file));
-               return 1;
-       }
-
-       // Fetch the endianess
-       const int endianess = ehdr.e_ident[EI_DATA];
-
-       // Fetch the .note header
-       offset = gelf_getnote(data, offset, &nhdr, &offset_name, &offset_data);
-       if (!offset) {
-               ERROR(file->ctx, "Could not read note section: %m\n");
-               return 1;
-       }
-
-       switch (nhdr.n_type) {
-               case NT_GNU_PROPERTY_TYPE_0:
-                       break;
-
-               // We are not interested in this here
-               default:
-                       return 0;
-       }
-
-#if 0
-       // Check if the name starts with "GNU"
-       if (nhdr.n_namesz == sizeof(ELF_NOTE_GNU) {
-               if (strcmp(data->d_buf + offset_name, ELF_NOTE_GNU) == 0)
-                       break;
-       }
-#endif
-
-       size_t length = nhdr.n_descsz;
-
-       // XXX Check if this is aligned to 8 bytes or 4 bytes on 32 bit
-
-       const char* payload = (const char*)data->d_buf + offset_data;
-
-       while (length) {
-               // Read the type and size of the .note section
-               const uint32_t type = read_4_bytes(endianess, payload);
-               const uint32_t size = read_4_bytes(endianess, payload + 4);
-
-               // Skip header
-               length -= sizeof(type) + sizeof(size);
-               payload += sizeof(type) + sizeof(size);
-
-               if (length < size) {
-                       ERROR(file->ctx, "GNU Property note has an incorrect format\n");
-                       return 1;
-               }
-
-               switch (ehdr.e_machine) {
-                       case EM_AARCH64:
-                               r = __pakfire_file_check_cf_protection_aarch64(file, endianess, type, payload);
-                               if (r)
-                                       return r;
-                               break;
-
-                       case EM_X86_64:
-                               r = __pakfire_file_check_cf_protection_x86(file, endianess, type, payload);
-                               if (r)
-                                       return r;
-                               break;
-
-                       default:
-                               ERROR(file->ctx, "Unsupported ELF type (%d)\n", ehdr.e_machine);
-                               return 1;
-               }
-
-               // Skip data part
-               length  -= (size + 7) & ~7;
-               payload += (size + 7) & ~7;
-       }
-
-       return 0;
-}
-
-static int __pakfire_file_check_cf_protection(struct pakfire_file* file, Elf* elf, void* data) {
-       return pakfire_file_for_elf_section(file, elf, SHT_NOTE, pakfire_file_check_cf_protection_callback);
-}
-
-static int pakfire_file_check_cf_protection(struct pakfire_file* file) {
-       return pakfire_file_open_elf(file, __pakfire_file_check_cf_protection, NULL);
-}
-
 int pakfire_file_check(struct pakfire_file* file, int* issues) {
        int r;
 
@@ -2519,11 +2285,6 @@ int pakfire_file_check(struct pakfire_file* file, int* issues) {
                        r = pakfire_file_check_debuginfo(file);
                        if (r)
                                return r;
-
-                       // Check CF protection
-                       r = pakfire_file_check_cf_protection(file);
-                       if (r)
-                               return r;
                }
 
 DONE:
index 7087aaf775fc1fcf4dbf2bdcf13d5b99ff0d129c..6b4e2eb3335505996ca138e3f32131244e4c5b63 100644 (file)
@@ -248,6 +248,42 @@ static int pakfire_linter_file_get_elf_type(struct pakfire_linter_file* lfile) {
        return type;
 }
 
+typedef int (*__pakfire_linter_file_for_elf_section_callback)(struct pakfire_linter_file* lfile,
+       Elf* elf, const Elf_Scn* section, const GElf_Shdr* shdr, Elf_Data* data);
+
+static int pakfire_linter_file_for_elf_section(struct pakfire_linter_file* lfile,
+               Elf* elf, const Elf64_Word type, __pakfire_linter_file_for_elf_section_callback callback) {
+       Elf_Scn* section = NULL;
+       GElf_Shdr shdr;
+       Elf_Data* data;
+       int r = -EINVAL;
+
+       // Walk through all sections
+       for (;;) {
+               section = elf_nextscn(elf, section);
+               if (!section)
+                       break;
+
+               // Fetch the section header
+               gelf_getshdr(section, &shdr);
+
+               // Skip sections that don't match
+               if (type && shdr.sh_type != type)
+                       continue;
+
+               // Fetch the data
+               data = elf_getdata(section, NULL);
+
+               // Call the callback
+               r = callback(lfile, elf, section, &shdr, data);
+               if (r)
+                       break;
+       }
+
+       return r;
+}
+
+
 static int pakfire_linter_file_get_elf_section(struct pakfire_linter_file* lfile,
                Elf* elf, const Elf64_Word type, Elf_Scn** section, GElf_Shdr* header, Elf_Data** data) {
        Elf_Scn* s = NULL;
@@ -594,6 +630,174 @@ static int pakfire_linter_file_check_runpath(struct pakfire_linter_file* lfile)
        return pakfire_linter_file_elf(lfile, __pakfire_linter_file_check_runpath, NULL);
 }
 
+static uint32_t read_4_bytes(const int endianess, const char* data) {
+       uint32_t bytes = 0;
+
+       switch (endianess) {
+               // Litte Endian
+               case ELFDATA2LSB:
+                       bytes = data[0] |
+                               ((uint32_t)data[1] << 8) |
+                               ((uint32_t)data[2] << 16) |
+                               ((uint32_t)data[3] << 24);
+                       break;
+
+               // Big endian
+               case ELFDATA2MSB:
+                       bytes = data[3] |
+                               ((uint32_t)data[2] << 8) |
+                               ((uint32_t)data[1] << 16) |
+                               ((uint32_t)data[0] << 24);
+                       break;
+       }
+
+       return bytes;
+}
+
+static int __pakfire_linter_file_check_cf_protection_aarch64(struct pakfire_linter_file* lfile,
+               const int endianess, const uint32_t type, const char* payload) {
+       # warning TODO
+       return 0;
+}
+
+static int __pakfire_linter_file_check_cf_protection_riscv64(struct pakfire_linter_file* lfile,
+               const int endianess, const uint32_t type, const char* payload) {
+       # warning TODO
+       return 0;
+}
+
+static int __pakfire_linter_file_check_cf_protection_x86(struct pakfire_linter_file* lfile,
+               const int endianess, const uint32_t type, const char* payload) {
+       switch (type) {
+               case GNU_PROPERTY_X86_FEATURE_1_AND:
+                       break;
+
+               // XXX what should we do in this case? Just ignore?
+               default:
+                       return 0;
+       }
+
+       uint32_t property = read_4_bytes(endianess, payload);
+
+       // Check for IBT
+       if (!(property & GNU_PROPERTY_X86_FEATURE_1_IBT))
+               return pakfire_linter_file_error(lfile, "Indirect Branch Tracking (IBT) is not enabled");
+
+       // Check for Shadow Stack
+       if (!(property & GNU_PROPERTY_X86_FEATURE_1_SHSTK))
+               return pakfire_linter_file_error(lfile, "Shadow Stack is not enabled");
+
+       return 0;
+}
+
+static int pakfire_linter_file_check_cf_protection_callback(
+               struct pakfire_linter_file* lfile, Elf* elf,
+               const Elf_Scn* section, const GElf_Shdr* shdr, Elf_Data* data) {
+       GElf_Ehdr ehdr = {};
+       GElf_Nhdr nhdr = {};
+       size_t offset = 0;
+       size_t offset_name = 0;
+       size_t offset_data = 0;
+       int r;
+
+       // Fetch the ELF header
+       if (!gelf_getehdr(elf, &ehdr)) {
+               ERROR(lfile->ctx, "Could not fetch the ELF header for %s: %m\n", lfile->path);
+               return -errno;
+       }
+
+       // Fetch the endianess
+       const int endianess = ehdr.e_ident[EI_DATA];
+
+       // Fetch the .note header
+       offset = gelf_getnote(data, offset, &nhdr, &offset_name, &offset_data);
+       if (!offset) {
+               ERROR(lfile->ctx, "Could not read note section: %m\n");
+               return -errno;
+       }
+
+       switch (nhdr.n_type) {
+               case NT_GNU_PROPERTY_TYPE_0:
+                       break;
+
+               // We are not interested in this here
+               default:
+                       return 0;
+       }
+
+#if 0
+       // Check if the name starts with "GNU"
+       if (nhdr.n_namesz == sizeof(ELF_NOTE_GNU) {
+               if (strcmp(data->d_buf + offset_name, ELF_NOTE_GNU) == 0)
+                       break;
+       }
+#endif
+
+       size_t length = nhdr.n_descsz;
+
+       // XXX Check if this is aligned to 8 bytes or 4 bytes on 32 bit
+
+       const char* payload = (const char*)data->d_buf + offset_data;
+
+       while (length) {
+               // Read the type and size of the .note section
+               const uint32_t type = read_4_bytes(endianess, payload);
+               const uint32_t size = read_4_bytes(endianess, payload + 4);
+
+               // Skip header
+               length -= sizeof(type) + sizeof(size);
+               payload += sizeof(type) + sizeof(size);
+
+               if (length < size) {
+                       ERROR(lfile->ctx, "GNU Property note has an incorrect format\n");
+                       return -EINVAL;
+               }
+
+               switch (ehdr.e_machine) {
+                       case EM_AARCH64:
+                               r = __pakfire_linter_file_check_cf_protection_aarch64(
+                                               lfile, endianess, type, payload);
+                               if (r < 0)
+                                       return r;
+                               break;
+
+                       case EM_RISCV:
+                               r = __pakfire_linter_file_check_cf_protection_riscv64(
+                                               lfile, endianess, type, payload);
+                               if (r < 0)
+                                       return r;
+                               break;
+
+                       case EM_X86_64:
+                               r = __pakfire_linter_file_check_cf_protection_x86(
+                                               lfile, endianess, type, payload);
+                               if (r < 0)
+                                       return r;
+                               break;
+
+                       default:
+                               ERROR(lfile->ctx, "Unsupported ELF type (%d)\n", ehdr.e_machine);
+                               return -ENOTSUP;
+               }
+
+               // Skip data part
+               length  -= (size + 7) & ~7;
+               payload += (size + 7) & ~7;
+       }
+
+       return 0;
+}
+
+static int __pakfire_linter_file_check_cf_protection(
+               struct pakfire_linter_file* lfile, Elf* elf, void* data) {
+       return pakfire_linter_file_for_elf_section(
+               lfile, elf, SHT_NOTE, pakfire_linter_file_check_cf_protection_callback);
+}
+
+static int pakfire_linter_file_check_cf_protection(struct pakfire_linter_file* lfile) {
+       return pakfire_linter_file_elf(lfile, __pakfire_linter_file_check_cf_protection, NULL);
+}
+
 int pakfire_linter_file_lint(struct pakfire_linter_file* lfile) {
        int r = 0;
 
@@ -635,6 +839,11 @@ int pakfire_linter_file_lint(struct pakfire_linter_file* lfile) {
                r = pakfire_linter_file_check_runpath(lfile);
                if (r < 0)
                        return r;
+
+               // CF Protection
+               r = pakfire_linter_file_check_cf_protection(lfile);
+               if (r < 0)
+                       return r;
        }
 
        return 0;