Re: fix must_not_trace_exec() test (was: 2.6.5-mm4)

[Olaf Dietsche <olaf+list.linux-kernel@olafdietsche.de>]

Andrew Morton <akpm@osdl.org> writes:

> ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.5/2.6.5-mm4/
>
> +compute-creds-race-fix.patch
> +compute-creds-race-fix-fix.patch
>
>  Fix possible race in permission calculation across exec()

this is a small fix for the modified must_not_trace_exec() test.
I have tested neither the compute-creds-race-fix nor my patch.
It is on top of 2.6.5 + compute-creds-race-fix.patch +
compute-creds-race-fix-fix.patch.

Although, I'd rather not lump together unrelated tests without
renaming must_not_trace_exec(). Btw, can someone enlighten me what
this atomic_read() test is all about.

Regards, Olaf.

diff -urN a/security/commoncap.c b/security/commoncap.c
--- a/security/commoncap.c	Mon Apr 12 10:38:17 2004
+++ b/security/commoncap.c	Mon Apr 12 11:10:38 2004
@@ -118,9 +118,9 @@
 static inline int must_not_trace_exec (struct task_struct *p)
 {
 	return ((p->ptrace & PT_PTRACED) && !(p->ptrace & PT_PTRACE_CAP))
-		|| atomic_read(&current->fs->count) > 1
-		|| atomic_read(&current->files->count) > 1
-		|| atomic_read(&current->sighand->count) > 1;
+		|| atomic_read(&p->fs->count) > 1
+		|| atomic_read(&p->files->count) > 1
+		|| atomic_read(&p->sighand->count) > 1;
 }
 
 void cap_bprm_apply_creds (struct linux_binprm *bprm)
diff -urN a/security/dummy.c b/security/dummy.c
--- a/security/dummy.c	Mon Apr 12 10:38:17 2004
+++ b/security/dummy.c	Mon Apr 12 11:10:50 2004
@@ -174,9 +174,9 @@
 static inline int must_not_trace_exec (struct task_struct *p)
 {
 	return ((p->ptrace & PT_PTRACED) && !(p->ptrace & PT_PTRACE_CAP))
-		|| atomic_read(&current->fs->count) > 1
-		|| atomic_read(&current->files->count) > 1
-		|| atomic_read(&current->sighand->count) > 1;
+		|| atomic_read(&p->fs->count) > 1
+		|| atomic_read(&p->files->count) > 1
+		|| atomic_read(&p->sighand->count) > 1;
 }
 
 static void dummy_bprm_apply_creds (struct linux_binprm *bprm)