Module Name:    src
Committed By:   martin
Date:           Fri Aug  4 13:15:25 UTC 2023

Modified Files:
        src/sys/uvm [netbsd-8]: uvm_map.c

Log Message:
Pull up following revision(s) (requested by riastradh in ticket #1880):

        sys/uvm/uvm_map.c: revision 1.403 (patch)

mmap(2): Avoid arithmetic overflow in search for free space.

PR kern/56900


To generate a diff of this commit:
cvs rdiff -u -r1.351.2.5 -r1.351.2.6 src/sys/uvm/uvm_map.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

Modified files:

Index: src/sys/uvm/uvm_map.c
diff -u src/sys/uvm/uvm_map.c:1.351.2.5 src/sys/uvm/uvm_map.c:1.351.2.6
--- src/sys/uvm/uvm_map.c:1.351.2.5	Sat Apr  1 16:05:00 2023
+++ src/sys/uvm/uvm_map.c	Fri Aug  4 13:15:25 2023
@@ -1,4 +1,4 @@
-/*	$NetBSD: uvm_map.c,v 1.351.2.5 2023/04/01 16:05:00 martin Exp $	*/
+/*	$NetBSD: uvm_map.c,v 1.351.2.6 2023/08/04 13:15:25 martin Exp $	*/
 
 /*
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -66,7 +66,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.351.2.5 2023/04/01 16:05:00 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.351.2.6 2023/08/04 13:15:25 martin Exp $");
 
 #include "opt_ddb.h"
 #include "opt_pax.h"
@@ -2014,7 +2014,21 @@ uvm_map_findspace(struct vm_map *map, va
 	/* Try to find the space in the red-black tree */
 
 	/* Check slot before any entry */
-	hint = topdown ? entry->next->start - length : entry->end;
+	if (topdown) {
+		KASSERTMSG(entry->next->start >= vm_map_min(map),
+		    "map=%p entry=%p entry->next=%p"
+		    " entry->next->start=0x%"PRIxVADDR" min=0x%"PRIxVADDR,
+		    map, entry, entry->next,
+		    entry->next->start, vm_map_min(map));
+		if (length > entry->next->start - vm_map_min(map))
+			hint = vm_map_min(map); /* XXX goto wraparound? */
+		else
+			hint = entry->next->start - length;
+		KASSERT(hint >= vm_map_min(map));
+	} else {
+		hint = entry->end;
+	}
+
 	switch (uvm_map_space_avail(&hint, length, uoffset, align, flags,
 	    topdown, entry)) {
 	case 1:

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