diff options
| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-07-24 16:21:27 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-07-24 16:21:27 +0200 |
| commit | 8f9aa2c90530ab92301a82231ae44f3722becd93 (patch) | |
| tree | fb282e955b0a880b07131a135257fe3ec764e928 /tools/lib/bpf | |
| parent | 93467b31bec6da512b51544e5e4584f2745e995e (diff) | |
| parent | 155b42bec9cbb6b8cdc47dd9bd09503a81fbe493 (diff) | |
Merge v7.1.5linux-rolling-stable
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/lib/bpf')
| -rw-r--r-- | tools/lib/bpf/btf.c | 4 | ||||
| -rw-r--r-- | tools/lib/bpf/gen_loader.c | 81 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 9 | ||||
| -rw-r--r-- | tools/lib/bpf/strset.c | 62 | ||||
| -rw-r--r-- | tools/lib/bpf/usdt.c | 16 |
5 files changed, 122 insertions, 50 deletions
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index ceb57b46a878..771aeaa0262b 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -4578,12 +4578,14 @@ static int btf_dedup_prep(struct btf_dedup *d) case BTF_KIND_RESTRICT: case BTF_KIND_PTR: case BTF_KIND_FWD: - case BTF_KIND_TYPEDEF: case BTF_KIND_FUNC: case BTF_KIND_FLOAT: case BTF_KIND_TYPE_TAG: h = btf_hash_common(t); break; + case BTF_KIND_TYPEDEF: + h = btf_hash_typedef(t); + break; case BTF_KIND_INT: case BTF_KIND_DECL_TAG: h = btf_hash_int_decl_tag(t); diff --git a/tools/lib/bpf/gen_loader.c b/tools/lib/bpf/gen_loader.c index 9478b8f78f26..40004aa3af71 100644 --- a/tools/lib/bpf/gen_loader.c +++ b/tools/lib/bpf/gen_loader.c @@ -398,13 +398,12 @@ int bpf_gen__finish(struct bpf_gen *gen, int nr_progs, int nr_maps) blob_fd_array_off(gen, i)); emit(gen, BPF_MOV64_IMM(BPF_REG_0, 0)); emit(gen, BPF_EXIT_INSN()); - if (OPTS_GET(gen->opts, gen_hash, false)) - compute_sha_update_offsets(gen); - - pr_debug("gen: finish %s\n", errstr(gen->error)); if (!gen->error) { struct gen_loader_opts *opts = gen->opts; + if (OPTS_GET(opts, gen_hash, false)) + compute_sha_update_offsets(gen); + opts->insns = gen->insn_start; opts->insns_sz = gen->insn_cur - gen->insn_start; opts->data = gen->data_start; @@ -419,6 +418,7 @@ int bpf_gen__finish(struct bpf_gen *gen, int nr_progs, int nr_maps) bpf_insn_bswap(insn++); } } + pr_debug("gen: finish %s\n", errstr(gen->error)); return gen->error; } @@ -545,13 +545,22 @@ void bpf_gen__map_create(struct bpf_gen *gen, default: break; } - /* conditionally update max_entries */ - if (map_idx >= 0) + + /* + * Conditionally update max_entries from the host-supplied loader + * ctx. This sizes the map at runtime, but for a signed loader + * (gen_hash) it would let an untrusted host re-dimension the + * program's maps after emit_signature_match(), outside what the + * signature attests to. Keep the signer-provided max_entries + * baked into the blob in that case. + */ + if (map_idx >= 0 && !OPTS_GET(gen->opts, gen_hash, false)) move_ctx2blob(gen, attr_field(map_create_attr, max_entries), 4, sizeof(struct bpf_loader_ctx) + sizeof(struct bpf_map_desc) * map_idx + offsetof(struct bpf_map_desc, max_entries), true /* check that max_entries != 0 */); + /* emit MAP_CREATE command */ emit_sys_bpf(gen, BPF_MAP_CREATE, map_create_attr, attr_size); debug_ret(gen, "map_create %s idx %d type %d value_size %d value_btf_id %d", @@ -585,6 +594,23 @@ static void emit_signature_match(struct bpf_gen *gen) __s64 off; int i; + /* + * Reject if the metadata map is not exclusive. Without exclusivity + * the cached map->sha[] verified above can be stale: another BPF + * program with map access could have mutated the contents between + * BPF_OBJ_GET_INFO_BY_FD and loader execution. + */ + emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX, + 0, 0, 0, 0)); + emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, SHA256_DIGEST_LENGTH)); + off = -(gen->insn_cur - gen->insn_start - gen->cleanup_label) / 8 - 2; + if (is_simm16(off)) { + emit(gen, BPF_MOV64_IMM(BPF_REG_7, -EINVAL)); + emit(gen, BPF_JMP_IMM(BPF_JNE, BPF_REG_2, 1, off)); + } else { + gen->error = -ERANGE; + } + for (i = 0; i < SHA256_DWORD_SIZE; i++) { emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX, 0, 0, 0, 0)); @@ -1053,7 +1079,7 @@ void bpf_gen__prog_load(struct bpf_gen *gen, prog_idx, prog_type, insns_off, insn_cnt, license_off); /* convert blob insns to target endianness */ - if (gen->swapped_endian) { + if (gen->swapped_endian && !gen->error) { struct bpf_insn *insn = gen->data_start + insns_off; int i; @@ -1091,7 +1117,7 @@ void bpf_gen__prog_load(struct bpf_gen *gen, sizeof(struct bpf_core_relo)); /* convert all info blobs to target endianness */ - if (gen->swapped_endian) + if (gen->swapped_endian && !gen->error) info_blob_bswap(gen, func_info, line_info, core_relos, load_attr); libbpf_strlcpy(attr.prog_name, prog_name, sizeof(attr.prog_name)); @@ -1169,27 +1195,36 @@ void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *pvalue, value = add_data(gen, pvalue, value_size); key = add_data(gen, &zero, sizeof(zero)); - /* if (map_desc[map_idx].initial_value) { + /* + * if (map_desc[map_idx].initial_value) { * if (ctx->flags & BPF_SKEL_KERNEL) * bpf_probe_read_kernel(value, value_size, initial_value); * else * bpf_copy_from_user(value, value_size, initial_value); * } + * + * The runtime initial_value comes from the host-supplied loader + * ctx and would overwrite the blob value after emit_signature_match() + * has already validated map->sha[]. For a signed loader (gen_hash) + * the attested blob value must be authoritative, so skip the override + * and leave the hashed value in place. */ - emit(gen, BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_6, - sizeof(struct bpf_loader_ctx) + - sizeof(struct bpf_map_desc) * map_idx + - offsetof(struct bpf_map_desc, initial_value))); - emit(gen, BPF_JMP_IMM(BPF_JEQ, BPF_REG_3, 0, 8)); - emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, - 0, 0, 0, value)); - emit(gen, BPF_MOV64_IMM(BPF_REG_2, value_size)); - emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_6, - offsetof(struct bpf_loader_ctx, flags))); - emit(gen, BPF_JMP_IMM(BPF_JSET, BPF_REG_0, BPF_SKEL_KERNEL, 2)); - emit(gen, BPF_EMIT_CALL(BPF_FUNC_copy_from_user)); - emit(gen, BPF_JMP_IMM(BPF_JA, 0, 0, 1)); - emit(gen, BPF_EMIT_CALL(BPF_FUNC_probe_read_kernel)); + if (!OPTS_GET(gen->opts, gen_hash, false)) { + emit(gen, BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_6, + sizeof(struct bpf_loader_ctx) + + sizeof(struct bpf_map_desc) * map_idx + + offsetof(struct bpf_map_desc, initial_value))); + emit(gen, BPF_JMP_IMM(BPF_JEQ, BPF_REG_3, 0, 8)); + emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE, + 0, 0, 0, value)); + emit(gen, BPF_MOV64_IMM(BPF_REG_2, value_size)); + emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_6, + offsetof(struct bpf_loader_ctx, flags))); + emit(gen, BPF_JMP_IMM(BPF_JSET, BPF_REG_0, BPF_SKEL_KERNEL, 2)); + emit(gen, BPF_EMIT_CALL(BPF_FUNC_copy_from_user)); + emit(gen, BPF_JMP_IMM(BPF_JA, 0, 0, 1)); + emit(gen, BPF_EMIT_CALL(BPF_FUNC_probe_read_kernel)); + } map_update_attr = add_data(gen, &attr, attr_size); pr_debug("gen: map_update_elem: idx %d, value: off %d size %d, attr: off %d size %d\n", diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 3a80a018fc7d..83aae7a39d36 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -12280,7 +12280,7 @@ error: static int attach_kprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link) { DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts); - unsigned long offset = 0; + long offset = 0; const char *func_name; char *func; int n; @@ -12302,6 +12302,13 @@ static int attach_kprobe(const struct bpf_program *prog, long cookie, struct bpf pr_warn("kprobe name is invalid: %s\n", func_name); return -EINVAL; } + + if (offset < 0) { + free(func); + pr_warn("kprobe offset must be a non-negative integer: %li\n", offset); + return -EINVAL; + } + if (opts.retprobe && offset != 0) { free(func); pr_warn("kretprobes do not support offset specification\n"); diff --git a/tools/lib/bpf/strset.c b/tools/lib/bpf/strset.c index 2464bcbd04e0..ace73c6b3d62 100644 --- a/tools/lib/bpf/strset.c +++ b/tools/lib/bpf/strset.c @@ -107,6 +107,41 @@ static void *strset_add_str_mem(struct strset *set, size_t add_sz) set->strs_data_len, set->strs_data_max_len, add_sz); } +static long strset_str_append(struct strset *set, const char *s) +{ + uintptr_t old_data = (uintptr_t)set->strs_data; + size_t old_data_len = set->strs_data_len; + uintptr_t old_s = (uintptr_t)s; + long len = strlen(s) + 1; + void *p; + + /* + * Hashmap keys are always offsets within set->strs_data, so to even + * look up some string from the "outside", we need to first append it + * at the end, so that it can be addressed with an offset. Luckily, + * until set->strs_data_len is incremented, that string is just a piece + * of garbage for the rest of the code, so no harm, no foul. On the + * other hand, if the string is unique, it's already appended and + * ready to be used, only a simple set->strs_data_len increment away. + */ + p = strset_add_str_mem(set, len); + if (!p) + return -ENOMEM; + + /* + * The set->strs_data might have reallocated and if 's' pointed + * to an internal string within the old buffer, then it became + * dangling and needs to be reconstructed before the copy. + */ + if (old_data && old_data != (uintptr_t)set->strs_data && + old_s >= old_data && old_s < old_data + old_data_len) + s = set->strs_data + (old_s - old_data); + + memcpy(p, s, len); + + return len; +} + /* Find string offset that corresponds to a given string *s*. * Returns: * - >0 offset into string data, if string is found; @@ -116,16 +151,12 @@ static void *strset_add_str_mem(struct strset *set, size_t add_sz) int strset__find_str(struct strset *set, const char *s) { long old_off, new_off, len; - void *p; - /* see strset__add_str() for why we do this */ - len = strlen(s) + 1; - p = strset_add_str_mem(set, len); - if (!p) - return -ENOMEM; + len = strset_str_append(set, s); + if (len < 0) + return len; new_off = set->strs_data_len; - memcpy(p, s, len); if (hashmap__find(set->strs_hash, new_off, &old_off)) return old_off; @@ -142,24 +173,13 @@ int strset__find_str(struct strset *set, const char *s) int strset__add_str(struct strset *set, const char *s) { long old_off, new_off, len; - void *p; int err; - /* Hashmap keys are always offsets within set->strs_data, so to even - * look up some string from the "outside", we need to first append it - * at the end, so that it can be addressed with an offset. Luckily, - * until set->strs_data_len is incremented, that string is just a piece - * of garbage for the rest of the code, so no harm, no foul. On the - * other hand, if the string is unique, it's already appended and - * ready to be used, only a simple set->strs_data_len increment away. - */ - len = strlen(s) + 1; - p = strset_add_str_mem(set, len); - if (!p) - return -ENOMEM; + len = strset_str_append(set, s); + if (len < 0) + return len; new_off = set->strs_data_len; - memcpy(p, s, len); /* Now attempt to add the string, but only if the string with the same * contents doesn't exist already (HASHMAP_ADD strategy). If such diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c index e3710933fd52..57fb82bb81b5 100644 --- a/tools/lib/bpf/usdt.c +++ b/tools/lib/bpf/usdt.c @@ -468,10 +468,10 @@ static int parse_elf_segs(Elf *elf, const char *path, struct elf_seg **segs, siz static int parse_vma_segs(int pid, const char *lib_path, struct elf_seg **segs, size_t *seg_cnt) { - char path[PATH_MAX], line[PATH_MAX], mode[16]; + char path[PATH_MAX], line[4096], mode[16]; size_t seg_start, seg_end, seg_off; struct elf_seg *seg; - int tmp_pid, i, err; + int tmp_pid, n, i, err; FILE *f; *seg_cnt = 0; @@ -480,8 +480,13 @@ static int parse_vma_segs(int pid, const char *lib_path, struct elf_seg **segs, * /proc/<pid>/root/<path>. They will be reported as just /<path> in * /proc/<pid>/maps. */ - if (sscanf(lib_path, "/proc/%d/root%s", &tmp_pid, path) == 2 && pid == tmp_pid) + /* %n is not counted in sscanf() return value, so initialize it. */ + n = 0; + if (sscanf(lib_path, "/proc/%d/root%n", &tmp_pid, &n) == 1 && + n > 0 && pid == tmp_pid && lib_path[n] == '/') { + libbpf_strlcpy(path, lib_path + n, sizeof(path)); goto proceed; + } if (!realpath(lib_path, path)) { pr_warn("usdt: failed to get absolute path of '%s' (err %s), using path as is...\n", @@ -504,8 +509,11 @@ proceed: * 7f5c6f5d1000-7f5c6f5d3000 rw-p 001c7000 08:04 21238613 /usr/lib64/libc-2.17.so * 7f5c6f5d3000-7f5c6f5d8000 rw-p 00000000 00:00 0 * 7f5c6f5d8000-7f5c6f5d9000 r-xp 00000000 103:01 362990598 /data/users/andriin/linux/tools/bpf/usdt/libhello_usdt.so + * + * Some VMA names can be longer than the local buffer. Bound the + * writes, but still consume the rest of the line. */ - while (fscanf(f, "%zx-%zx %s %zx %*s %*d%[^\n]\n", + while (fscanf(f, "%zx-%zx %15s %zx %*s %*d%4095[^\n]%*[^\n]\n", &seg_start, &seg_end, mode, &seg_off, line) == 5) { void *tmp; |
