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[PATCH] Fix GCC6 -Wnull-dereference warnings.
- From: Mark Wielaard <mjw at redhat dot com>
- To: elfutils-devel at lists dot fedorahosted dot org
- Date: Sat, 13 Feb 2016 00:08:43 +0100
- Subject: [PATCH] Fix GCC6 -Wnull-dereference warnings.
asm_begin.c: In function ‘asm_begin’:
asm_begin.c:62:7: error: potential null pointer dereference [-Werror=null-dereference]
__fsetlocking (result->out.file, FSETLOCKING_BYCALLER);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We set result to NULL just before this call in case of error.
Fixed by only calling __fsetlocking when result is not NULL.
strip.c: In function ‘handle_elf.constprop’:
strip.c:1270:31: error: null pointer dereference [-Werror=null-dereference]
elf_assert ((versiondata->d_size / sizeof (Elf32_Word))
~~~~~~~~~~~^~~
src/strip.c:597:37: note: in definition of macro ‘elf_assert’
#define elf_assert(test) do { if (!(test)) goto illformed; } while (0)
^~~~
That is the wrong check, we want to check shndxdata, not versiondata here.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
---
libasm/ChangeLog | 5 +++++
libasm/asm_begin.c | 4 ++--
src/ChangeLog | 4 ++++
src/strip.c | 6 ++++--
4 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/libasm/ChangeLog b/libasm/ChangeLog
index beb6211..a8ac2c7 100644
--- a/libasm/ChangeLog
+++ b/libasm/ChangeLog
@@ -1,3 +1,8 @@
+2016-02-12 Mark Wielaard <mjw@redhat.com>
+
+ * asm_begin.c (prepare_text_output): Only call __fsetlocking when
+ result isn't NULL.
+
2015-10-05 Josh Stone <jistone@redhat.com>
* Makefile.am (libasm.so): Add AM_V_CCLD and AM_V_at silencers.
diff --git a/libasm/asm_begin.c b/libasm/asm_begin.c
index ff4d94c..dc83cd8 100644
--- a/libasm/asm_begin.c
+++ b/libasm/asm_begin.c
@@ -58,8 +58,8 @@ prepare_text_output (AsmCtx_t *result)
free (result);
result = NULL;
}
-
- __fsetlocking (result->out.file, FSETLOCKING_BYCALLER);
+ else
+ __fsetlocking (result->out.file, FSETLOCKING_BYCALLER);
}
return result;
diff --git a/src/ChangeLog b/src/ChangeLog
index 71709e4..369b12c 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2016-02-12 Mark Wielaard <mjw@redhat.com>
+
+ * strip.c (handle_elf): Correct elf_assert shndxdata check.
+
2016-02-09 Mark Wielaard <mjw@redhat.com>
* readelf.c (read_encoded): Move up.
diff --git a/src/strip.c b/src/strip.c
index 06d7cfd..a604244 100644
--- a/src/strip.c
+++ b/src/strip.c
@@ -1267,8 +1267,10 @@ handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
shndxdata = elf_getdata (shdr_info[shdr_info[cnt].symtab_idx].scn,
NULL);
- elf_assert ((versiondata->d_size / sizeof (Elf32_Word))
- >= shdr_info[cnt].data->d_size / elsize);
+ elf_assert (shndxdata != NULL
+ && shndxdata->d_buf != NULL
+ && ((shndxdata->d_size / sizeof (Elf32_Word))
+ >= shdr_info[cnt].data->d_size / elsize));
}
if (shdr_info[cnt].version_idx != 0)
--
2.5.0