[Qemu-devel] [Qemu] [PATCH] Fix crash caused by missing command line arguments

[Qemu-devel] [Qemu] [PATCH] Fix crash caused by missing command line arguments

[Stefan Weil]

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Hi,

some command line parameters for Qemu user mode take arguments.
When Qemu is called with a parameter and the argument is missing,
it gets a SIGSEGV crash.

This patch tries to fix it for Linux user mode. Other user modes
are expected to need similar fixes, but I cannot test them.

Regards
Stefan Weil



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Missing command line arguments caused a crash.

Signed-off-by: Stefan Weil <weil@mail.berlios.de>

Index: trunk/linux-user/main.c
===================================================================
--- trunk.orig/linux-user/main.c	2009-02-04 19:22:22.000000000 +0100
+++ trunk/linux-user/main.c	2009-02-04 19:44:03.000000000 +0100
@@ -2301,6 +2301,8 @@
             if (envlist_unsetenv(envlist, r) != 0)
                 usage();
         } else if (!strcmp(r, "s")) {
+            if (optind >= argc)
+                break;
             r = argv[optind++];
             x86_stack_size = strtol(r, (char **)&r, 0);
             if (x86_stack_size <= 0)
@@ -2312,6 +2314,8 @@
         } else if (!strcmp(r, "L")) {
             interp_prefix = argv[optind++];
         } else if (!strcmp(r, "p")) {
+            if (optind >= argc)
+                break;
             qemu_host_page_size = atoi(argv[optind++]);
             if (qemu_host_page_size == 0 ||
                 (qemu_host_page_size & (qemu_host_page_size - 1)) != 0) {
@@ -2319,12 +2323,14 @@
                 exit(1);
             }
         } else if (!strcmp(r, "g")) {
+            if (optind >= argc)
+                break;
             gdbstub_port = atoi(argv[optind++]);
 	} else if (!strcmp(r, "r")) {
 	    qemu_uname_release = argv[optind++];
         } else if (!strcmp(r, "cpu")) {
             cpu_model = argv[optind++];
-            if (strcmp(cpu_model, "?") == 0) {
+            if (cpu_model == NULL || strcmp(cpu_model, "?") == 0) {
 /* XXX: implement xxx_cpu_list for targets that still miss it */
 #if defined(cpu_list)
                     cpu_list(stdout, &fprintf);

Re: [Qemu-devel] [Qemu] [PATCH] Fix crash caused by missing command line arguments

[Aurelien Jarno]

On Wed, Feb 04, 2009 at 07:51:28PM +0100, Stefan Weil wrote:
> Hi,
> 
> some command line parameters for Qemu user mode take arguments.
> When Qemu is called with a parameter and the argument is missing,
> it gets a SIGSEGV crash.
> 
> This patch tries to fix it for Linux user mode. Other user modes
> are expected to need similar fixes, but I cannot test them.
> 
> Regards
> Stefan Weil
> 
> 

Thanks, applied.

> Missing command line arguments caused a crash.
> 
> Signed-off-by: Stefan Weil <weil@mail.berlios.de>
> 
> Index: trunk/linux-user/main.c
> ===================================================================
> --- trunk.orig/linux-user/main.c	2009-02-04 19:22:22.000000000 +0100
> +++ trunk/linux-user/main.c	2009-02-04 19:44:03.000000000 +0100
> @@ -2301,6 +2301,8 @@
>              if (envlist_unsetenv(envlist, r) != 0)
>                  usage();
>          } else if (!strcmp(r, "s")) {
> +            if (optind >= argc)
> +                break;
>              r = argv[optind++];
>              x86_stack_size = strtol(r, (char **)&r, 0);
>              if (x86_stack_size <= 0)
> @@ -2312,6 +2314,8 @@
>          } else if (!strcmp(r, "L")) {
>              interp_prefix = argv[optind++];
>          } else if (!strcmp(r, "p")) {
> +            if (optind >= argc)
> +                break;
>              qemu_host_page_size = atoi(argv[optind++]);
>              if (qemu_host_page_size == 0 ||
>                  (qemu_host_page_size & (qemu_host_page_size - 1)) != 0) {
> @@ -2319,12 +2323,14 @@
>                  exit(1);
>              }
>          } else if (!strcmp(r, "g")) {
> +            if (optind >= argc)
> +                break;
>              gdbstub_port = atoi(argv[optind++]);
>  	} else if (!strcmp(r, "r")) {
>  	    qemu_uname_release = argv[optind++];
>          } else if (!strcmp(r, "cpu")) {
>              cpu_model = argv[optind++];
> -            if (strcmp(cpu_model, "?") == 0) {
> +            if (cpu_model == NULL || strcmp(cpu_model, "?") == 0) {
>  /* XXX: implement xxx_cpu_list for targets that still miss it */
>  #if defined(cpu_list)
>                      cpu_list(stdout, &fprintf);


-- 
Aurelien Jarno	                        GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net