From e70da8e2e976b377d257e1b3b13de2941a7e4d60 Mon Sep 17 00:00:00 2001 From: mjg Date: Fri, 18 Dec 2015 16:33:15 +0000 Subject: proc: fix a race which could result in dereference of bad p_pgrp pointer on fork During fork p_starcopy - p_endcopy area of a process is populated with bcopy with only proc lock held. Another forking thread can find such a process and proceed to access p_pgrp included in said area. Fix the problem by moving the field outside. It is being properly assigned later. Reviewed by: kib Diagnosed by: kib Tested by: Fabian Keil MFC after: 10 days --- sys/kern/kern_proc.c | 1 + 1 file changed, 1 insertion(+) (limited to 'sys/kern/kern_proc.c') diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c index 8a3b6ca..bbedd9b 100644 --- a/sys/kern/kern_proc.c +++ b/sys/kern/kern_proc.c @@ -248,6 +248,7 @@ proc_init(void *mem, int size, int flags) TAILQ_INIT(&p->p_threads); /* all threads in proc */ EVENTHANDLER_INVOKE(process_init, p); p->p_stats = pstats_alloc(); + p->p_pgrp = NULL; SDT_PROBE3(proc, , init, return, p, size, flags); return (0); } -- cgit v1.1