Discussion:
PR23946, illegal memory access in readelf.c:slurp_ia64_unwind_table
(too old to reply)
Alan Modra
2018-12-01 11:55:51 UTC
Permalink
PR 23946
* readelf.c (slurp_ia64_unwind_table): Bounds check symbol index
on reloc.
(slurp_hppa_unwind_table): Likewise.

diff --git a/binutils/readelf.c b/binutils/readelf.c
index 9eb5931fe3..9969e46ea4 100644
--- a/binutils/readelf.c
+++ b/binutils/readelf.c
@@ -7597,9 +7597,9 @@ slurp_ia64_unwind_table (Filedata * filedata,

for (rp = rela; rp < rela + nrelas; ++rp)
{
+ unsigned int sym_ndx;
unsigned int r_type = get_reloc_type (filedata, rp->r_info);
relname = elf_ia64_reloc_type (r_type);
- sym = aux->symtab + get_reloc_symindex (rp->r_info);

/* PR 17531: file: 9fa67536. */
if (relname == NULL)
@@ -7623,6 +7623,15 @@ slurp_ia64_unwind_table (Filedata * filedata,
continue;
}

+ sym_ndx = get_reloc_symindex (rp->r_info);
+ if (sym_ndx >= aux->nsyms)
+ {
+ warn (_("Skipping reloc with invalid symbol index: %u\n"),
+ sym_ndx);
+ continue;
+ }
+ sym = aux->symtab + sym_ndx;
+
switch (rp->r_offset / eh_addr_size % 3)
{
case 0:
@@ -8053,9 +8062,9 @@ slurp_hppa_unwind_table (Filedata * filedata,

for (rp = rela; rp < rela + nrelas; ++rp)
{
+ unsigned int sym_ndx;
unsigned int r_type = get_reloc_type (filedata, rp->r_info);
relname = elf_hppa_reloc_type (r_type);
- sym = aux->symtab + get_reloc_symindex (rp->r_info);

if (relname == NULL)
{
@@ -8077,6 +8086,15 @@ slurp_hppa_unwind_table (Filedata * filedata,
continue;
}

+ sym_ndx = get_reloc_symindex (rp->r_info);
+ if (sym_ndx >= aux->nsyms)
+ {
+ warn (_("Skipping reloc with invalid symbol index: %u\n"),
+ sym_ndx);
+ continue;
+ }
+ sym = aux->symtab + sym_ndx;
+
switch ((rp->r_offset % unw_ent_size) / 4)
{
case 0:
--
Alan Modra
Australia Development Lab, IBM
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