[PATCH][UML] Boot broken due to buffer overrun

Balbir Singh
2008-11-29T10:08:59Z

mconsole_init() passed 256 bytes as length in os_create_unix_socket, while
the sizeof UNIX_PATH_MAX is 108. This patch fixes that problem and avoids
a big overrun bug reported on UML bootup.

Reported-by: Vikas K Managutte <vikki.km@gmail.com>
Reported-by: Sarvesh Kumar Lal Das <skldas@gmail.com>
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---

arch/um/drivers/mconsole_kern.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff -puN arch/um/drivers/mconsole_kern.c~fix-uml-buggy-socket-creation arch/um/drivers/mconsole_kern.c
--- linux-2.6.28-rc6/arch/um/drivers/mconsole_kern.c~fix-uml-buggy-socket-creation 2008-11-29 15:29:04.000000000 +0530
+++ linux-2.6.28-rc6-balbir/arch/um/drivers/mconsole_kern.c 2008-11-29 15:32:23.000000000 +0530
@@ -16,6 +16,8 @@
#include <linux/slab.h>
#include <linux/syscalls.h>
#include <linux/utsname.h>
+#include <linux/socket.h>
+#include <linux/un.h>
#include <linux/workqueue.h>
#include <linux/mutex.h>
#include <asm/uaccess.h>
@@ -785,7 +787,7 @@ static int __init mconsole_init(void)
/* long to avoid size mismatch warnings from gcc */
long sock;
int err;
- char file[256];
+ char file[UNIX_PATH_MAX];

if (umid_file_name("mconsole", file, sizeof(file)))
return -1;
_

--
Balbir