Re: [PATCH v3 1/6] Support Mips architecture

[Ying Huang]

Hi Mark,

Next time I send a patch, I will add ChangeLog entry in commit message and 
check the added file.

Thanks,

Ying


在 2024/3/29 08:18, Mark Wielaard 写道:
> Hi Ying,
>
> On Tue, Mar 05, 2024 at 05:51:17PM +0800, Ying Huang wrote:
>> From: Ying Huang 
>>
>> Signed-off-by: Ying Huang 
>> ---
>>  backends/Makefile.am|   6 +-
>>  backends/mips_init.c|  52 
>>  backends/mips_reloc.def |  93 +++
>>  backends/mips_symbol.c  |  63 +
>>  libebl/eblopenbackend.c |   2 +
>>  libelf/libelfP.h|   3 +
>>  tests/libelf.h  | 541 
> Note that this adds tests/libelf.h by accident.  I see how that could
> happen, because it should have been in .gitignore.  I posted a patch
> to do that:
> https://inbox.sourceware.org/elfutils-devel/20240328234308.1032110-1-m...@klomp.org/
>
> Besides that the patch looks fine. I did add a ChangeLog entry to the
> commit message. Pushed as attached.
>
> Thanks,
>
> Mark

[PATCH] readelf: Fix division by zero in handle a relocation sections

[Maks Mishin]

Variable 'sh_entsize', whose possible value set allows a zero value
by calling function 'gelf_fsize', is used as a denominator
in calculation of 'nentries' variable.

Found by RASU JSC.

Signed-off-by: Maks Mishin 
---
 src/readelf.c | 18 ++
 1 file changed, 18 insertions(+)

diff --git a/src/readelf.c b/src/readelf.c
index 0e931184..6701f5cf 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -2086,6 +2086,12 @@ handle_relocs_rel (Ebl *ebl, GElf_Ehdr *ehdr, Elf_Scn 
*scn, GElf_Shdr *shdr)
 {
   int class = gelf_getclass (ebl->elf);
   size_t sh_entsize = gelf_fsize (ebl->elf, ELF_T_REL, 1, EV_CURRENT);
+
+  if (sh_entsize == 0) {
+   printf (_("division by zero in handle_relocs_rel() function"));
+   return;
+  }
+
   int nentries = shdr->sh_size / sh_entsize;
 
   /* Get the data of the section.  */
@@ -2275,6 +2281,12 @@ handle_relocs_rela (Ebl *ebl, GElf_Ehdr *ehdr, Elf_Scn 
*scn, GElf_Shdr *shdr)
 {
   int class = gelf_getclass (ebl->elf);
   size_t sh_entsize = gelf_fsize (ebl->elf, ELF_T_RELA, 1, EV_CURRENT);
+
+  if (sh_entsize == 0) {
+   printf (_("division by zero in handle_relocs_rela() function"));
+   return;
+  }
+
   int nentries = shdr->sh_size / sh_entsize;
 
   /* Get the data of the section.  */
@@ -2469,6 +2481,12 @@ handle_relocs_relr (Ebl *ebl, Dwfl_Module *mod, Elf_Scn 
*scn, GElf_Shdr *shdr)
 {
   int class = gelf_getclass (ebl->elf);
   size_t sh_entsize = gelf_fsize (ebl->elf, ELF_T_RELR, 1, EV_CURRENT);
+  
+  if (sh_entsize == 0) {
+   printf (_("division by zero in handle_relocs_relr() function"));
+   return;
+  }
+
   int nentries = shdr->sh_size / sh_entsize;
 
   /* Get the data of the section.  */
-- 
2.30.2

[PATCH] readelf: Fix deref-of-null in handle_core_item()

[Maks Mishin]

Return value of a function 'gelf_getehdr' is dereferenced
without checking for NULL, but it is usually checked for this function.

Found by RASU JSC.

Signed-off-by: Maks Mishin 
---
 src/readelf.c | 7 +++
 1 file changed, 7 insertions(+)

diff --git a/src/readelf.c b/src/readelf.c
index 0e931184..f2ec358f 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -12440,6 +12440,13 @@ handle_core_item (Elf *core, const Ebl_Core_Item 
*item, const void *desc,
 field went into the high half of USEC.  */
  GElf_Ehdr ehdr_mem;
  GElf_Ehdr *ehdr = gelf_getehdr (core, &ehdr_mem);
+
+ if (ehdr == NULL)
+   {
+ error (0, 0, _("cannot read ELF header: %s"), elf_errmsg (-1));
+ return;
+   }
+
  if (likely (ehdr->e_ident[EI_DATA] == ELFDATA2MSB))
usec >>= 32;
  else
-- 
2.30.2