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[PATCH] elfcmp: Add some NULL and zero checks.
- From: Mark Wielaard <mjw at redhat dot com>
- To: elfutils-devel at lists dot fedorahosted dot org
- Date: Sun, 04 Jan 2015 00:37:05 +0100
- Subject: [PATCH] elfcmp: Add some NULL and zero checks.
https://bugzilla.redhat.com/show_bug.cgi?id=1170810#c17
Reported-by: Alexander Cherepanov <cherepan@mccme.ru>
Signed-off-by: Mark Wielaard <mjw@redhat.com>
---
src/ChangeLog | 6 ++++++
src/elfcmp.c | 20 +++++++++++++-------
2 files changed, 19 insertions(+), 7 deletions(-)
diff --git a/src/ChangeLog b/src/ChangeLog
index 5adf07d..dad984e 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2015-01-03 Mark Wielaard <mjw@redhat.com>
+
+ * elfcmp (main): Check section name is not NULL. Check sh_entsize
+ is not zero for symbol tables. Check phdrs are not NULL.
+ (search_for_copy_reloc): Check sh_entsize is not zero.
+
2014-12-30 Mark Wielaard <mjw@redhat.com>
* elflint.c (check_scn_group): Check d_buf and name are not NULL.
diff --git a/src/elfcmp.c b/src/elfcmp.c
index d1008b3..f8a4572 100644
--- a/src/elfcmp.c
+++ b/src/elfcmp.c
@@ -287,7 +287,8 @@ main (int argc, char *argv[])
/* Compare the headers. We allow the name to be at a different
location. */
- if (unlikely (strcmp (sname1, sname2) != 0))
+ if (unlikely (sname1 == NULL || sname2 == NULL
+ || strcmp (sname1, sname2) != 0))
{
error (0, 0, gettext ("%s %s differ: section [%zu], [%zu] name"),
fname1, fname2, elf_ndxscn (scn1), elf_ndxscn (scn2));
@@ -295,8 +296,8 @@ main (int argc, char *argv[])
}
/* We ignore certain sections. */
- if (strcmp (sname1, ".gnu_debuglink") == 0
- || strcmp (sname1, ".gnu.prelink_undo") == 0)
+ if ((sname1 != NULL && strcmp (sname1, ".gnu_debuglink") == 0)
+ || (sname1 != NULL && strcmp (sname1, ".gnu.prelink_undo") == 0))
continue;
if (shdr1->sh_type != shdr2->sh_type
@@ -333,6 +334,11 @@ main (int argc, char *argv[])
{
case SHT_DYNSYM:
case SHT_SYMTAB:
+ if (shdr1->sh_entsize == 0)
+ error (2, 0,
+ gettext ("symbol table [%zu] in '%s' has zero sh_entsize"),
+ elf_ndxscn (scn1), fname1);
+
/* Iterate over the symbol table. We ignore the st_size
value of undefined symbols. */
for (int ndx = 0; ndx < (int) (shdr1->sh_size / shdr1->sh_entsize);
@@ -591,13 +597,13 @@ cannot read note section [%zu] '%s' in '%s': %s"),
{
GElf_Phdr phdr1_mem;
GElf_Phdr *phdr1 = gelf_getphdr (elf1, ndx, &phdr1_mem);
- if (ehdr1 == NULL)
+ if (phdr1 == NULL)
error (2, 0,
gettext ("cannot get program header entry %d of '%s': %s"),
ndx, fname1, elf_errmsg (-1));
GElf_Phdr phdr2_mem;
GElf_Phdr *phdr2 = gelf_getphdr (elf2, ndx, &phdr2_mem);
- if (ehdr2 == NULL)
+ if (phdr2 == NULL)
error (2, 0,
gettext ("cannot get program header entry %d of '%s': %s"),
ndx, fname2, elf_errmsg (-1));
@@ -760,7 +766,7 @@ search_for_copy_reloc (Ebl *ebl, size_t scnndx, int symndx)
gettext ("cannot get content of section %zu: %s"),
elf_ndxscn (scn), elf_errmsg (-1));
- if (shdr->sh_type == SHT_REL)
+ if (shdr->sh_type == SHT_REL && shdr->sh_entsize != 0)
for (int ndx = 0; ndx < (int) (shdr->sh_size / shdr->sh_entsize);
++ndx)
{
@@ -774,7 +780,7 @@ search_for_copy_reloc (Ebl *ebl, size_t scnndx, int symndx)
&& ebl_copy_reloc_p (ebl, GELF_R_TYPE (rel->r_info)))
return true;
}
- else
+ else if (shdr->sh_entsize != 0)
for (int ndx = 0; ndx < (int) (shdr->sh_size / shdr->sh_entsize);
++ndx)
{
--
2.1.0