commit 75f2de448f311807e2493f2a37a980e2d872b229

Author: Mark Wielaard <mark@klomp.org>

Date:   Thu Nov 3 13:38:45 2022 +0100

    readelf: Check phdr != NULL or shdr != NULL in handle_dynamic.

    The compiler doesn't know that when use_dynamic_segment is true,

    then phdr should/will be non-NULL and otherwise shdr is non-NULL.

    Add explicit checks to help the compiler out and in case an error

    is made calling the handle_dynamic function.

    Signed-off-by: Mark Wielaard <mark@klomp.org>

diff --git a/src/readelf.c b/src/readelf.c

index 0e0b05c4..e721a209 100644

--- a/src/readelf.c

+++ b/src/readelf.c

@@ -1828,7 +1828,7 @@ handle_dynamic (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr, GElf_Phdr *phdr)

   size_t dyn_ents;

   /* Get the data of the section.  */

-  if (use_dynamic_segment)

+  if (use_dynamic_segment && phdr != NULL)

     data = elf_getdata_rawchunk(ebl->elf, phdr->p_offset,

 				phdr->p_filesz, ELF_T_DYN);

   else

@@ -1840,7 +1840,7 @@ handle_dynamic (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr, GElf_Phdr *phdr)

   /* Get the dynamic section entry number */

   dyn_ents = get_dyn_ents (data);

-  if (!use_dynamic_segment)

+  if (!use_dynamic_segment && shdr != NULL)

     {

       /* Get the section header string table index.  */

       if (unlikely (elf_getshdrstrndx (ebl->elf, &shstrndx) < 0))

@@ -1862,7 +1862,7 @@ handle_dynamic (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr, GElf_Phdr *phdr)

 	      (int) shdr->sh_link,

 	      elf_strptr (ebl->elf, shstrndx, glink->sh_name));

     }

-  else

+  else if (phdr != NULL)

     {

       printf (ngettext ("\

 \nDynamic segment contains %lu entry:\n Addr: %#0*" PRIx64 "  Offset: %#08" PRIx64 "\n",

@@ -1879,7 +1879,7 @@ handle_dynamic (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr, GElf_Phdr *phdr)

   /* if --use-dynamic option is enabled,

      use the string table to get the related library info.  */

   Elf_Data *strtab_data = NULL;

-  if (use_dynamic_segment)

+  if (use_dynamic_segment && phdr != NULL)

     {

       strtab_data = get_dynscn_strtab(ebl->elf, phdr);

       if (strtab_data == NULL)

@@ -1903,7 +1903,7 @@ handle_dynamic (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr, GElf_Phdr *phdr)

 	  || dyn->d_tag == DT_RPATH

 	  || dyn->d_tag == DT_RUNPATH)

 	{

-	  if (! use_dynamic_segment)

+	  if (! use_dynamic_segment && shdr != NULL)

 	    name = elf_strptr (ebl->elf, shdr->sh_link, dyn->d_un.d_val);

 	  else if (dyn->d_un.d_val < strtab_data->d_size

 		   && memrchr (strtab_data->d_buf + dyn->d_un.d_val, '\0',

commit b0a0235771906e3bcd6174c4e3c020b5522b0be5

Author: Mark Wielaard <mark@klomp.org>

Date:   Thu Nov 3 13:44:35 2022 +0100

    libdw: Don't dereference and assign values we are skipping

    We don't use the FDE address encoding byte, so no reason

    to read and store it. Just skip past it.

    Signed-off-by: Mark Wielaard <mark@klomp.org>

diff --git a/libdw/dwarf_next_cfi.c b/libdw/dwarf_next_cfi.c

index 23b16885..be08984f 100644

--- a/libdw/dwarf_next_cfi.c

+++ b/libdw/dwarf_next_cfi.c

@@ -226,7 +226,7 @@ dwarf_next_cfi (const unsigned char e_ident[],

 	      if (sized_augmentation)

 		{

 		  /* Skip FDE address encoding byte.  */

-		  encoding = *bytes++;

+		  bytes++;

 		  continue;

 		}

 	      break;

commit 52a6a3110e019d696284fdd822c2a2f0987dded2

Author: Mark Wielaard <mark@klomp.org>

Date:   Thu Nov 3 13:52:32 2022 +0100

    readelf: Check gelf_getdyn doesn't return NULL

    Signed-off-by: Mark Wielaard <mark@klomp.org>

diff --git a/src/readelf.c b/src/readelf.c

index e721a209..3dafb041 100644

--- a/src/readelf.c

+++ b/src/readelf.c

@@ -4910,7 +4910,7 @@ get_dynscn_addrs(Elf *elf, GElf_Phdr *phdr, GElf_Addr addrs[i_max])

     GElf_Dyn dyn_mem;

     GElf_Dyn *dyn = gelf_getdyn(data, dyn_idx, &dyn_mem);

     /* DT_NULL Marks end of dynamic section.  */

-    if (dyn->d_tag == DT_NULL)

+    if (dyn == NULL || dyn->d_tag == DT_NULL)

       break;

     switch (dyn->d_tag) {