1 files changed, 83 insertions, 38 deletions

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 7afa8a117139..2007f8f003e3 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -217,7 +217,7 @@ bool filename__has_section(const char *filename, const char *sec)
 	GElf_Shdr shdr;
 	bool found = false;
 
-	fd = open(filename, O_RDONLY);
+	fd = open(filename, O_RDONLY | O_CLOEXEC);
 	if (fd < 0)
 		return false;
 
@@ -834,10 +834,24 @@ static int elf_read_build_id(Elf *elf, void *bf, size_t size)
 	ptr = data->d_buf;
 	while (ptr < (data->d_buf + data->d_size)) {
 		GElf_Nhdr *nhdr = ptr;
-		size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
-		       descsz = NOTE_ALIGN(nhdr->n_descsz);
+		size_t namesz, descsz, remaining;
 		const char *name;
 
+		/* ensure the note header fits within the section */
+		if (ptr + sizeof(*nhdr) > data->d_buf + data->d_size)
+			break;
+
+		namesz = NOTE_ALIGN(nhdr->n_namesz);
+		descsz = NOTE_ALIGN(nhdr->n_descsz);
+
+		/* validate individually to avoid size_t overflow on 32-bit */
+		remaining = data->d_buf + data->d_size - ptr - sizeof(*nhdr);
+		if (namesz > remaining || descsz > remaining - namesz) {
+			pr_warning("%s: oversized note: n_namesz=%u, n_descsz=%u\n",
+				   __func__, nhdr->n_namesz, nhdr->n_descsz);
+			break;
+		}
+
 		ptr += sizeof(*nhdr);
 		name = ptr;
 		ptr += namesz;
@@ -871,7 +885,7 @@ static int read_build_id(const char *filename, struct build_id *bid)
 	if (size < BUILD_ID_SIZE)
 		goto out;
 
-	fd = open(filename, O_RDONLY);
+	fd = open(filename, O_RDONLY | O_CLOEXEC);
 	if (fd < 0)
 		goto out;
 
@@ -919,12 +933,14 @@ int filename__read_build_id(const char *filename, struct build_id *bid)
 			return -1;
 		}
 		close(fd);
-		filename = path;
+		/* non-empty path means a temp file was created */
+		if (path[0] != '\0')
+			filename = path;
 	}
 
 	err = read_build_id(filename, bid);
 
-	if (m.comp)
+	if (m.comp && filename == path)
 		unlink(filename);
 	return err;
 }
@@ -934,7 +950,7 @@ int sysfs__read_build_id(const char *filename, struct build_id *bid)
 	size_t size = sizeof(bid->data);
 	int fd, err = -1;
 
-	fd = open(filename, O_RDONLY);
+	fd = open(filename, O_RDONLY | O_CLOEXEC);
 	if (fd < 0)
 		goto out;
 
@@ -960,17 +976,28 @@ int sysfs__read_build_id(const char *filename, struct build_id *bid)
 					err = 0;
 					break;
 				}
-			} else if (read(fd, bf, descsz) != (ssize_t)descsz)
-				break;
+			} else {
+				/* descsz from untrusted file — clamp to buffer */
+				if (descsz > sizeof(bf))
+					break;
+				if (read(fd, bf, descsz) != (ssize_t)descsz)
+					break;
+			}
 		} else {
-			int n = namesz + descsz;
+			size_t n;
 
-			if (n > (int)sizeof(bf)) {
+			/* int sum of namesz+descsz can overflow negative, bypassing size check */
+			if (namesz > sizeof(bf) || descsz > sizeof(bf) - namesz) {
 				n = sizeof(bf);
 				pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
 					 __func__, filename, nhdr.n_namesz, nhdr.n_descsz);
+			} else {
+				n = namesz + descsz;
 			}
-			if (read(fd, bf, n) != n)
+			/* no valid note has both namesz and descsz zero */
+			if (n == 0)
+				break;
+			if (read(fd, bf, n) != (ssize_t)n)
 				break;
 		}
 	}
@@ -994,7 +1021,7 @@ int filename__read_debuglink(const char *filename, char *debuglink,
 	if (err >= 0)
 		goto out;
 
-	fd = open(filename, O_RDONLY);
+	fd = open(filename, O_RDONLY | O_CLOEXEC);
 	if (fd < 0)
 		goto out;
 
@@ -1023,7 +1050,14 @@ int filename__read_debuglink(const char *filename, char *debuglink,
 		goto out_elf_end;
 
 	/* the start of this section is a zero-terminated string */
-	strncpy(debuglink, data->d_buf, size);
+	if (data->d_size > 0) {
+		size_t len = min(size - 1, data->d_size);
+
+		memcpy(debuglink, data->d_buf, len);
+		debuglink[len] = '\0';
+	} else {
+		debuglink[0] = '\0';
+	}
 
 	err = 0;
 
@@ -1108,9 +1142,9 @@ static Elf *read_gnu_debugdata(struct dso *dso, Elf *elf, const char *name, int
 		return NULL;
 	}
 
-	temp_fd = mkstemp(temp_filename);
+	temp_fd = mkostemp(temp_filename, O_CLOEXEC);
 	if (temp_fd < 0) {
-		pr_debug("%s: mkstemp: %m\n", __func__);
+		pr_debug("%s: mkostemp: %m\n", __func__);
 		*dso__load_errno(dso) = -errno;
 		fclose(wrapped);
 		return NULL;
@@ -1152,7 +1186,7 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
 
 		type = dso__symtab_type(dso);
 	} else {
-		fd = open(name, O_RDONLY);
+		fd = open(name, O_RDONLY | O_CLOEXEC);
 		if (fd < 0) {
 			*dso__load_errno(dso) = errno;
 			return -1;
@@ -1341,6 +1375,24 @@ static u64 ref_reloc(struct kmap *kmap)
 void __weak arch__sym_update(struct symbol *s __maybe_unused,
 		GElf_Sym *sym __maybe_unused) { }
 
+struct remap_kernel_ctx {
+	u64 sh_addr;
+	u64 sh_size;
+	u64 sh_offset;
+	struct kmap *kmap;
+};
+
+static int remap_kernel_cb(struct map *map, void *data)
+{
+	struct remap_kernel_ctx *ctx = data;
+
+	map__set_start(map, ctx->sh_addr + ref_reloc(ctx->kmap));
+	map__set_end(map, map__start(map) + ctx->sh_size);
+	map__set_pgoff(map, ctx->sh_offset);
+	map__set_mapping_type(map, MAPPING_TYPE__DSO);
+	return 0;
+}
+
 static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
 				      GElf_Sym *sym, GElf_Shdr *shdr,
 				      struct maps *kmaps, struct kmap *kmap,
@@ -1371,22 +1423,15 @@ static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
 		 * map to the kernel dso.
 		 */
 		if (*remap_kernel && dso__kernel(dso) && !kmodule) {
+			struct remap_kernel_ctx ctx = {
+				.sh_addr = shdr->sh_addr,
+				.sh_size = shdr->sh_size,
+				.sh_offset = shdr->sh_offset,
+				.kmap = kmap
+			};
+
 			*remap_kernel = false;
-			map__set_start(map, shdr->sh_addr + ref_reloc(kmap));
-			map__set_end(map, map__start(map) + shdr->sh_size);
-			map__set_pgoff(map, shdr->sh_offset);
-			map__set_mapping_type(map, MAPPING_TYPE__DSO);
-			/* Ensure maps are correctly ordered */
-			if (kmaps) {
-				int err;
-				struct map *tmp = map__get(map);
-
-				maps__remove(kmaps, map);
-				err = maps__insert(kmaps, map);
-				map__put(tmp);
-				if (err)
-					return err;
-			}
+			maps__mutate_mapping(kmaps, map, remap_kernel_cb, &ctx);
 		}
 
 		/*
@@ -1945,7 +1990,7 @@ static int kcore__open(struct kcore *kcore, const char *filename)
 {
 	GElf_Ehdr *ehdr;
 
-	kcore->fd = open(filename, O_RDONLY);
+	kcore->fd = open(filename, O_RDONLY | O_CLOEXEC);
 	if (kcore->fd == -1)
 		return -1;
 
@@ -1976,9 +2021,9 @@ static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
 	kcore->elfclass = elfclass;
 
 	if (temp)
-		kcore->fd = mkstemp(filename);
+		kcore->fd = mkostemp(filename, O_CLOEXEC);
 	else
-		kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
+		kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL | O_CLOEXEC, 0400);
 	if (kcore->fd == -1)
 		return -1;
 
@@ -2454,11 +2499,11 @@ static int kcore_copy__compare_files(const char *from_filename,
 {
 	int from, to, err = -1;
 
-	from = open(from_filename, O_RDONLY);
+	from = open(from_filename, O_RDONLY | O_CLOEXEC);
 	if (from < 0)
 		return -1;
 
-	to = open(to_filename, O_RDONLY);
+	to = open(to_filename, O_RDONLY | O_CLOEXEC);
 	if (to < 0)
 		goto out_close_from;
 
@@ -2876,7 +2921,7 @@ int get_sdt_note_list(struct list_head *head, const char *target)
 	Elf *elf;
 	int fd, ret;
 
-	fd = open(target, O_RDONLY);
+	fd = open(target, O_RDONLY | O_CLOEXEC);
 	if (fd < 0)
 		return -EBADF;