kern_tame.c: fix strncmp call

2015-08-23 Thread Caspar Schutijser 
Patch below.

Thanks,
Caspar Schutijser


Index: sys/kern/kern_tame.c
===
RCS file: /cvs/src/sys/kern/kern_tame.c,v
retrieving revision 1.25
diff -u -p -r1.25 kern_tame.c
--- sys/kern/kern_tame.c23 Aug 2015 19:32:20 -  1.25
+++ sys/kern/kern_tame.c23 Aug 2015 21:22:38 -
@@ -423,7 +423,7 @@ tame_namei(struct proc *p, char *origpat
 */
if ((p-p_p-ps_tame  _TM_TMPPATH) 
(p-p_tame_syscall == SYS_unlink) 
-   strncmp(path, /tmp/, sizeof(/tmp) - 1) == 0) {
+   strncmp(path, /tmp/, sizeof(/tmp/) - 1) == 0) {
return (0);
}

Re: kern_tame.c: fix strncmp call

2015-08-23 Thread patrick keshishian 
On 8/23/15, Caspar Schutijser cas...@schutijser.com wrote:
 Patch below.

 Thanks,
 Caspar Schutijser


 Index: sys/kern/kern_tame.c
 ===
 RCS file: /cvs/src/sys/kern/kern_tame.c,v
 retrieving revision 1.25
 diff -u -p -r1.25 kern_tame.c
 --- sys/kern/kern_tame.c  23 Aug 2015 19:32:20 -  1.25
 +++ sys/kern/kern_tame.c  23 Aug 2015 21:22:38 -
 @@ -423,7 +423,7 @@ tame_namei(struct proc *p, char *origpat
*/
   if ((p-p_p-ps_tame  _TM_TMPPATH) 
   (p-p_tame_syscall == SYS_unlink) 
 - strncmp(path, /tmp/, sizeof(/tmp) - 1) == 0) {
 + strncmp(path, /tmp/, sizeof(/tmp/) - 1) == 0) {

you are confusing sizeof() with strlen(). former counts the byte
required for the terminating NUL.

$ cat /tmp/a.c
#include stdio.h
#include stdlib.h

int main(int argc, char *argv[])
{
printf(sizeof(\/tmp\)=%zu\n, sizeof(/tmp));
exit(0);
}
$ cc  /tmp/a.c -o /tmp/a
$ /tmp/a
sizeof(/tmp)=5

--patrick

   return (0);
   }

Re: kern_tame.c: fix strncmp call

2015-08-23 Thread patrick keshishian 
Apologies, my eyes failed me on this.

On 8/23/15, patrick keshishian pkesh...@gmail.com wrote:
 On 8/23/15, Caspar Schutijser cas...@schutijser.com wrote:
 Patch below.

 Thanks,
 Caspar Schutijser


 Index: sys/kern/kern_tame.c
 ===
 RCS file: /cvs/src/sys/kern/kern_tame.c,v
 retrieving revision 1.25
 diff -u -p -r1.25 kern_tame.c
 --- sys/kern/kern_tame.c 23 Aug 2015 19:32:20 -  1.25
 +++ sys/kern/kern_tame.c 23 Aug 2015 21:22:38 -
 @@ -423,7 +423,7 @@ tame_namei(struct proc *p, char *origpat
   */
  if ((p-p_p-ps_tame  _TM_TMPPATH) 
  (p-p_tame_syscall == SYS_unlink) 
 -strncmp(path, /tmp/, sizeof(/tmp) - 1) == 0) {
 +strncmp(path, /tmp/, sizeof(/tmp/) - 1) == 0) {

 you are confusing sizeof() with strlen(). former counts the byte
 required for the terminating NUL.

 $ cat /tmp/a.c
 #include stdio.h
 #include stdlib.h

 int main(int argc, char *argv[])
 {
   printf(sizeof(\/tmp\)=%zu\n, sizeof(/tmp));
   exit(0);
 }
 $ cc  /tmp/a.c -o /tmp/a
 $ /tmp/a
 sizeof(/tmp)=5

 --patrick

  return (0);
  }

Re: kern_tame.c: fix strncmp call

2015-08-23 Thread Alexander Hall 

On 08/24/15 00:29, patrick keshishian wrote:

On 8/23/15, Caspar Schutijser cas...@schutijser.com wrote:

Patch below.

Thanks,
Caspar Schutijser


Index: sys/kern/kern_tame.c
===
RCS file: /cvs/src/sys/kern/kern_tame.c,v
retrieving revision 1.25
diff -u -p -r1.25 kern_tame.c
--- sys/kern/kern_tame.c23 Aug 2015 19:32:20 -  1.25
+++ sys/kern/kern_tame.c23 Aug 2015 21:22:38 -
@@ -423,7 +423,7 @@ tame_namei(struct proc *p, char *origpat
 */
if ((p-p_p-ps_tame  _TM_TMPPATH) 
(p-p_tame_syscall == SYS_unlink) 
-   strncmp(path, /tmp/, sizeof(/tmp) - 1) == 0) {
+   strncmp(path, /tmp/, sizeof(/tmp/) - 1) == 0) {


you are confusing sizeof() with strlen(). former counts the byte
required for the terminating NUL.


Yes, but you're missing the following - 1, methinks...

I think the diff is correct.

/Alexander



$ cat /tmp/a.c
#include stdio.h
#include stdlib.h

int main(int argc, char *argv[])
{
printf(sizeof(\/tmp\)=%zu\n, sizeof(/tmp));
exit(0);
}
$ cc  /tmp/a.c -o /tmp/a
$ /tmp/a
sizeof(/tmp)=5

--patrick


return (0);
}

Re: kern_tame.c: fix strncmp call

2015-08-23 Thread Joerg Sonnenberger 
On Sun, Aug 23, 2015 at 03:29:46PM -0700, patrick keshishian wrote:
 On 8/23/15, Caspar Schutijser cas...@schutijser.com wrote:
  Patch below.
 
  Thanks,
  Caspar Schutijser
 
 
  Index: sys/kern/kern_tame.c
  ===
  RCS file: /cvs/src/sys/kern/kern_tame.c,v
  retrieving revision 1.25
  diff -u -p -r1.25 kern_tame.c
  --- sys/kern/kern_tame.c23 Aug 2015 19:32:20 -  1.25
  +++ sys/kern/kern_tame.c23 Aug 2015 21:22:38 -
  @@ -423,7 +423,7 @@ tame_namei(struct proc *p, char *origpat
   */
  if ((p-p_p-ps_tame  _TM_TMPPATH) 
  (p-p_tame_syscall == SYS_unlink) 
  -   strncmp(path, /tmp/, sizeof(/tmp) - 1) == 0) {
  +   strncmp(path, /tmp/, sizeof(/tmp/) - 1) == 0) {
 
 you are confusing sizeof() with strlen(). former counts the byte
 required for the terminating NUL.

I don't think the OP is. If you want to check that path starts with
/tmp/, you need to check the first 5 characters. The original code
only checks the first 4. As such, it will also match /tmpfile.

Joerg