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] 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: