From: Alan Modra <amodra@gmail.com>
To: binutils@sourceware.org
Subject: som.c buffer overflow
Date: Wed, 26 Oct 2022 15:38:20 +1030 [thread overview]
Message-ID: <Y1jAxD+NxpMIah6s@squeak.grove.modra.org> (raw)
Fuzzed object files can put random values in bfd_reloc->address,
leading to large som_reloc_skip output.
* som.c (som_write_fixups): Allow for maximal som_reloc_skip.
diff --git a/bfd/som.c b/bfd/som.c
index 9b0a5513209..b9114e630fe 100644
--- a/bfd/som.c
+++ b/bfd/som.c
@@ -3005,10 +3005,12 @@ som_write_fixups (bfd *abfd,
then dump the current buffer contents now. Also reinitialize
the relocation queue.
- No single BFD relocation could ever translate into more
- than 100 bytes of SOM relocations (20bytes is probably the
- upper limit, but leave lots of space for growth). */
- if (p - tmp_space + 100 > SOM_TMP_BUFSIZE)
+ A single BFD relocation would probably only ever
+ translate into at most 20 bytes of SOM relocations.
+ However with fuzzed object files and resulting silly
+ values for "skip" below, som_reloc_skip can emit 262
+ bytes. Leave lots of space for growth. */
+ if (p - tmp_space + 512 > SOM_TMP_BUFSIZE)
{
amt = p - tmp_space;
if (bfd_bwrite ((void *) tmp_space, amt, abfd) != amt)
--
Alan Modra
Australia Development Lab, IBM
reply other threads:[~2022-10-26 5:08 UTC|newest]
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