GCC10 -fanalyzer plus -flto sees that ebl_openbackend can fail and
return NULL. Most of the time we will get a dummy ebl, but in case
of out of memory or corrupt ELF header it might return NULL. Make
sure that we report a (fatal) error in that case in all tools.
Signed-off-by: Mark Wielaard <m...@klomp.org>
---
src/ChangeLog | 7 +++++++
src/elflint.c | 9 ++++++++-
src/nm.c | 16 +++++++++-------
src/objdump.c | 3 +++
4 files changed, 27 insertions(+), 8 deletions(-)
diff --git a/src/ChangeLog b/src/ChangeLog
index 83d58607..8c72e7d1 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2020-05-09 Mark Wielaard <m...@klomp.org>
+
+ * elflint.c (process_elf_file): Error out if ebl_openbackend fails.
+ * objdump.c (handle_elf): Likewise.
+ * nm.c (handle_elf): Likewise. Move full name string construction
+ forward, so it can be used in the error message.
+
2020-04-17 Mark Wielaard <m...@klomp.org>
* readelf.c (print_debug): Check .gnu.debuglto_ prefix.
diff --git a/src/elflint.c b/src/elflint.c
index 0ef43236..6ad9bc42 100644
--- a/src/elflint.c
+++ b/src/elflint.c
@@ -4775,7 +4775,14 @@ process_elf_file (Elf *elf, const char *prefix, const
char *suffix,
ebl = ebl_openbackend (elf);
/* If there is no appropriate backend library we cannot test
architecture and OS specific features. Any encountered extension
- is an error. */
+ is an error. Often we'll get a "dummy" ebl, except if something
+ really bad happen, like a totally corrupted ELF file or out of
+ memory situation. */
+ if (ebl == NULL)
+ {
+ ERROR (gettext ("cannot create backend for ELF file\n"));
+ return;
+ }
/* Go straight by the gABI, check all the parts in turn. */
check_elf_header (ebl, ehdr, size);
diff --git a/src/nm.c b/src/nm.c
index b7c2aed6..f6ca3b0a 100644
--- a/src/nm.c
+++ b/src/nm.c
@@ -1510,8 +1510,17 @@ handle_elf (int fd, Elf *elf, const char *prefix, const
char *fname,
GElf_Ehdr *ehdr;
Ebl *ebl;
+ /* Create the full name of the file. */
+ if (prefix != NULL)
+ cp = mempcpy (cp, prefix, prefix_len);
+ cp = mempcpy (cp, fname, fname_len);
+ if (suffix != NULL)
+ memcpy (cp - 1, suffix, suffix_len + 1);
+
/* Get the backend for this object file type. */
ebl = ebl_openbackend (elf);
+ if (ebl == NULL)
+ INTERNAL_ERROR (fullname);
/* We need the ELF header in a few places. */
ehdr = gelf_getehdr (elf, &ehdr_mem);
@@ -1530,13 +1539,6 @@ handle_elf (int fd, Elf *elf, const char *prefix, const
char *fname,
goto out;
}
- /* Create the full name of the file. */
- if (prefix != NULL)
- cp = mempcpy (cp, prefix, prefix_len);
- cp = mempcpy (cp, fname, fname_len);
- if (suffix != NULL)
- memcpy (cp - 1, suffix, suffix_len + 1);
-
/* Find the symbol table.
XXX Can there be more than one? Do we print all? Currently we do. */
diff --git a/src/objdump.c b/src/objdump.c
index a619674f..82d7bcf6 100644
--- a/src/objdump.c
+++ b/src/objdump.c
@@ -755,6 +755,9 @@ handle_elf (Elf *elf, const char *prefix, const char *fname,
/* Get the backend for this object file type. */
Ebl *ebl = ebl_openbackend (elf);
+ if (ebl == NULL)
+ error (EXIT_FAILURE, 0,
+ gettext ("cannot create backend for elf file"));
printf ("%s: elf%d-%s\n\n",
fname, gelf_getclass (elf) == ELFCLASS32 ? 32 : 64,
--
2.20.1
