From 5b86194734d4021158312898e9e6e403cbbb7480 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mario=20H=C3=BCttel?= <mario.huettel@gmx.net>
Date: Wed, 4 Jan 2023 14:53:25 +0100
Subject: [PATCH 1/3] Remove reading of program headers. It is not necessary.

---
 src/elfpatch.c | 17 -----------------
 1 file changed, 17 deletions(-)

diff --git a/src/elfpatch.c b/src/elfpatch.c
index e1f7ef1..390284f 100644
--- a/src/elfpatch.c
+++ b/src/elfpatch.c
@@ -232,9 +232,6 @@ static int elf_patch_update_info(elfpatch_handle_t *ep)
 {
 	Elf_Kind ek;
 	const char *type_string = "unrecognized";
-	size_t header_count = 0ull;
-	GElf_Phdr phdr;
-	size_t i;
 
 	ret_val_if_ep_err(ep, -1001);
 
@@ -276,20 +273,6 @@ static int elf_patch_update_info(elfpatch_handle_t *ep)
 		return -1;
 	}
 
-	/* Get program headers */
-	if ( elf_getphdrnum(ep->elf, &header_count) != 0) {
-		print_err("Error reading count of program headers: %s\n", elf_errmsg(-1));
-		return -1;
-	}
-
-	for (i = 0ull; i < header_count; i++) {
-		if (gelf_getphdr(ep->elf, (int)i, &phdr) != &phdr) {
-			print_err("Error reading program header (%zu): %s\n", i, elf_errmsg(-1));
-			return -1;
-		}
-		print_debug("Read program header %zu\n", i);
-	}
-
 	return 0;
 }
 

From e09a07b3d32d171849d8c3a16b8d61ff3d63a01e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mario=20H=C3=BCttel?= <mario.huettel@gmx.net>
Date: Wed, 4 Jan 2023 15:04:06 +0100
Subject: [PATCH 2/3] Fix segmentation fault if a NOBITS section is specified
 as a source section

---
 src/elfpatch.c | 10 +++++++++-
 src/main.c     |  7 +++++--
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/elfpatch.c b/src/elfpatch.c
index 390284f..7e9c3a0 100644
--- a/src/elfpatch.c
+++ b/src/elfpatch.c
@@ -423,8 +423,16 @@ int elf_patch_compute_crc_over_section(elfpatch_handle_t *ep, const char *sectio
 	}
 
 	print_debug("Section data length: %lu\n", data->d_size);
-	if (!data->d_size)
+	if (!data->d_size) {
 		print_err("Section %s contains no data.\n", section);
+		return -2;
+	}
+
+	/* NOBIT sections have a length but no data in the file. Abort in this case */
+	if (!data->d_buf) {
+		print_err("Section %s does not contain loadable data.\n", section);
+		return -2;
+	}
 
 	/* If big endian or granularity is byte, simply compute CRC. No reordering is necessary */
 	if (!little_endian || granularity == GRANULARITY_BYTE) {
diff --git a/src/main.c b/src/main.c
index 97c2047..bc14947 100644
--- a/src/main.c
+++ b/src/main.c
@@ -407,12 +407,14 @@ int main(int argc, char **argv)
 	/* Check if all sections are present */
 	if (check_all_sections_present(ep, cmd_opts.section_list)) {
 		ret = -2;
-		goto free_cmds;
+		goto ret_close_elf;
 	}
 
 	/* Compute CRCs over sections */
 	crcs = (uint32_t *)malloc(sl_list_length(cmd_opts.section_list) * sizeof(uint32_t));
-	compute_crcs(ep, cmd_opts.section_list, &cmd_opts, crcs);
+	if (compute_crcs(ep, cmd_opts.section_list, &cmd_opts, crcs)) {
+		goto ret_close_elf;
+	}
 
 	if (reporting_get_verbosity()) {
 		print_crcs(cmd_opts.section_list, crcs);
@@ -427,6 +429,7 @@ int main(int argc, char **argv)
 		}
 	}
 
+ret_close_elf:
 	elf_patch_close_and_free(ep);
 
 free_cmds:

From 2fca25d4c0e4d7e8f7d26621757f991d1163f342 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mario=20H=C3=BCttel?= <mario.huettel@gmx.net>
Date: Wed, 4 Jan 2023 15:07:01 +0100
Subject: [PATCH 3/3] Fix segmentation fault if a NOBITS section is specified
 for output

---
 src/elfpatch.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/elfpatch.c b/src/elfpatch.c
index 7e9c3a0..978f8e6 100644
--- a/src/elfpatch.c
+++ b/src/elfpatch.c
@@ -534,6 +534,11 @@ int elf_patch_write_crcs_to_section(elfpatch_handle_t *ep, const char *section,
 	/* Get data object of section */
 	output_sec_data = elf_getdata(output_section->scn, NULL);
 	sec_bytes = (uint8_t *)output_sec_data->d_buf;
+	if (!sec_bytes) {
+		print_err("Output section '%s' does not contain loadable data. It has to be allocated in the ELF file\n",
+			  section);
+		goto ret_err;
+	}
 
 	/* Check the start and end magics */
 	if (check_start_magic) {