Merge tag 'perf-tools-fixes-for-v6.17-2025-09-05' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools fixes from Namhyung Kim:
 "Fixes for use-after-free that resulted in segfaults after merging the
  bpf tree.

  Also a couple of build and test fixes"

* tag 'perf-tools-fixes-for-v6.17-2025-09-05' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
  perf symbol-elf: Add support for the block argument for libbfd
  perf test: Checking BPF metadata collection fails on version string
  perf tests: Fix "PE file support" test build
  perf bpf-utils: Harden get_bpf_prog_info_linear
  perf bpf-utils: Constify bpil_array_desc
  perf bpf-event: Fix use-after-free in synthesis

1 files changed, 39 insertions, 22 deletions

diff --git a/tools/perf/util/bpf-utils.c b/tools/perf/util/bpf-utils.c
index 80b1d2b3729b..5a66dc8594aa 100644
--- a/tools/perf/util/bpf-utils.c
+++ b/tools/perf/util/bpf-utils.c
@@ -20,7 +20,7 @@ struct bpil_array_desc {
 				 */
 };
 
-static struct bpil_array_desc bpil_array_desc[] = {
+static const struct bpil_array_desc bpil_array_desc[] = {
 	[PERF_BPIL_JITED_INSNS] = {
 		offsetof(struct bpf_prog_info, jited_prog_insns),
 		offsetof(struct bpf_prog_info, jited_prog_len),
@@ -115,7 +115,7 @@ get_bpf_prog_info_linear(int fd, __u64 arrays)
 	__u32 info_len = sizeof(info);
 	__u32 data_len = 0;
 	int i, err;
-	void *ptr;
+	__u8 *ptr;
 
 	if (arrays >> PERF_BPIL_LAST_ARRAY)
 		return ERR_PTR(-EINVAL);
@@ -126,15 +126,15 @@ get_bpf_prog_info_linear(int fd, __u64 arrays)
 		pr_debug("can't get prog info: %s", strerror(errno));
 		return ERR_PTR(-EFAULT);
 	}
+	if (info.type >= __MAX_BPF_PROG_TYPE)
+		pr_debug("%s:%d: unexpected program type %u\n", __func__, __LINE__, info.type);
 
 	/* step 2: calculate total size of all arrays */
 	for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) {
+		const struct bpil_array_desc *desc = &bpil_array_desc[i];
 		bool include_array = (arrays & (1UL << i)) > 0;
-		struct bpil_array_desc *desc;
 		__u32 count, size;
 
-		desc = bpil_array_desc + i;
-
 		/* kernel is too old to support this field */
 		if (info_len < desc->array_offset + sizeof(__u32) ||
 		    info_len < desc->count_offset + sizeof(__u32) ||
@@ -163,19 +163,20 @@ get_bpf_prog_info_linear(int fd, __u64 arrays)
 	ptr = info_linear->data;
 
 	for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) {
-		struct bpil_array_desc *desc;
+		const struct bpil_array_desc *desc = &bpil_array_desc[i];
 		__u32 count, size;
 
 		if ((arrays & (1UL << i)) == 0)
 			continue;
 
-		desc  = bpil_array_desc + i;
 		count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
 		size  = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
 		bpf_prog_info_set_offset_u32(&info_linear->info,
 					     desc->count_offset, count);
 		bpf_prog_info_set_offset_u32(&info_linear->info,
 					     desc->size_offset, size);
+		assert(ptr >= info_linear->data);
+		assert(ptr < &info_linear->data[data_len]);
 		bpf_prog_info_set_offset_u64(&info_linear->info,
 					     desc->array_offset,
 					     ptr_to_u64(ptr));
@@ -189,27 +190,45 @@ get_bpf_prog_info_linear(int fd, __u64 arrays)
 		free(info_linear);
 		return ERR_PTR(-EFAULT);
 	}
+	if (info_linear->info.type >= __MAX_BPF_PROG_TYPE) {
+		pr_debug("%s:%d: unexpected program type %u\n",
+			 __func__, __LINE__, info_linear->info.type);
+	}
 
 	/* step 6: verify the data */
+	ptr = info_linear->data;
 	for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) {
-		struct bpil_array_desc *desc;
-		__u32 v1, v2;
+		const struct bpil_array_desc *desc = &bpil_array_desc[i];
+		__u32 count1, count2, size1, size2;
+		__u64 ptr2;
 
 		if ((arrays & (1UL << i)) == 0)
 			continue;
 
-		desc = bpil_array_desc + i;
-		v1 = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
-		v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
+		count1 = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
+		count2 = bpf_prog_info_read_offset_u32(&info_linear->info,
 						   desc->count_offset);
-		if (v1 != v2)
-			pr_warning("%s: mismatch in element count\n", __func__);
+		if (count1 != count2) {
+			pr_warning("%s: mismatch in element count %u vs %u\n", __func__, count1, count2);
+			free(info_linear);
+			return ERR_PTR(-ERANGE);
+		}
 
-		v1 = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
-		v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
+		size1 = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
+		size2 = bpf_prog_info_read_offset_u32(&info_linear->info,
 						   desc->size_offset);
-		if (v1 != v2)
-			pr_warning("%s: mismatch in rec size\n", __func__);
+		if (size1 != size2) {
+			pr_warning("%s: mismatch in rec size %u vs %u\n", __func__, size1, size2);
+			free(info_linear);
+			return ERR_PTR(-ERANGE);
+		}
+		ptr2 = bpf_prog_info_read_offset_u64(&info_linear->info, desc->array_offset);
+		if (ptr_to_u64(ptr) != ptr2) {
+			pr_warning("%s: mismatch in array %p vs %llx\n", __func__, ptr, ptr2);
+			free(info_linear);
+			return ERR_PTR(-ERANGE);
+		}
+		ptr += roundup(count1 * size1, sizeof(__u64));
 	}
 
 	/* step 7: update info_len and data_len */
@@ -224,13 +243,12 @@ void bpil_addr_to_offs(struct perf_bpil *info_linear)
 	int i;
 
 	for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) {
-		struct bpil_array_desc *desc;
+		const struct bpil_array_desc *desc = &bpil_array_desc[i];
 		__u64 addr, offs;
 
 		if ((info_linear->arrays & (1UL << i)) == 0)
 			continue;
 
-		desc = bpil_array_desc + i;
 		addr = bpf_prog_info_read_offset_u64(&info_linear->info,
 						     desc->array_offset);
 		offs = addr - ptr_to_u64(info_linear->data);
@@ -244,13 +262,12 @@ void bpil_offs_to_addr(struct perf_bpil *info_linear)
 	int i;
 
 	for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) {
-		struct bpil_array_desc *desc;
+		const struct bpil_array_desc *desc = &bpil_array_desc[i];
 		__u64 addr, offs;
 
 		if ((info_linear->arrays & (1UL << i)) == 0)
 			continue;
 
-		desc = bpil_array_desc + i;
 		offs = bpf_prog_info_read_offset_u64(&info_linear->info,
 						     desc->array_offset);
 		addr = offs + ptr_to_u64(info_linear->data);