From: Daniel Axtens <d...@axtens.net>
Under tftp errors, we print a tftp error message from the tftp header.
However, the tftph pointer is a pointer inside nb, the netbuff. Previously,
we were freeing the nb and then dereferencing it. Don't do that, use it
and then free it later.
This isn't really _bad_ per se, especially as we're single-threaded, but
it trips up fuzzers.
Signed-off-by: Daniel Axtens <d...@axtens.net>
Reviewed-by: Daniel Kiper <daniel.ki...@oracle.com>
---
grub-core/net/tftp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/grub-core/net/tftp.c b/grub-core/net/tftp.c
index ee305e18a..7dbd3056d 100644
--- a/grub-core/net/tftp.c
+++ b/grub-core/net/tftp.c
@@ -251,9 +251,9 @@ tftp_receive (grub_net_udp_socket_t sock __attribute__
((unused)),
return GRUB_ERR_NONE;
case TFTP_ERROR:
data->have_oack = 1;
- grub_netbuff_free (nb);
grub_error (GRUB_ERR_IO, "%s", tftph->u.err.errmsg);
grub_error_save (&data->save_err);
+ grub_netbuff_free (nb);
return GRUB_ERR_NONE;
default:
grub_netbuff_free (nb);
--
2.11.0
_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/grub-devel
