From: Andi Kleen <ak@suse.de>

This addresses one of the review comments earlier for the user core
patchkit: when the core dump handler is executed make sure there is no
potential for recursion in case it crashes again.

This currently does it for all pipe user mode helpers.  In theory it could
be done only for core dump user helpers, but there are currently no other
users of this function.

Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 kernel/kmod.c |    4 ++++
 1 files changed, 4 insertions(+)

diff -puN kernel/kmod.c~support-piping-into-commands-in-proc-sys-kernel-core_pattern-fix-2 kernel/kmod.c
--- a/kernel/kmod.c~support-piping-into-commands-in-proc-sys-kernel-core_pattern-fix-2
+++ a/kernel/kmod.c
@@ -35,6 +35,7 @@
 #include <linux/mount.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
+#include <linux/resource.h>
 #include <asm/uaccess.h>
 
 extern int max_threads;
@@ -158,6 +159,9 @@ static int ____call_usermodehelper(void 
 		FD_SET(0, fdt->open_fds);
 		FD_CLR(0, fdt->close_on_exec);
 		spin_unlock(&f->file_lock);
+
+		/* and disallow core files too */
+		current->signal->rlim[RLIMIT_CORE] = (struct rlimit){0, 0};
 	}
 
 	/* We can run anywhere, unlike our parent keventd(). */
_