From: Andreas Schwab <schwab@suse.de>
To: linux-ia64@vger.kernel.org
Subject: Missing overflow check in mmap
Date: Mon, 05 Apr 2004 16:49:45 +0000 [thread overview]
Message-ID: <jek70u74k6.fsf@sykes.suse.de> (raw)
Calling mmap with len = -1 was silently accepted.
Andreas.
--- linux-2.6.5/arch/ia64/kernel/sys_ia64.c.~1~ 2004-04-04 05:37:23.000000000 +0200
+++ linux-2.6.5/arch/ia64/kernel/sys_ia64.c 2004-04-05 18:16:24.424002264 +0200
@@ -201,10 +201,16 @@ do_mmap2 (unsigned long addr, unsigned l
* A zero mmap always succeeds in Linux, independent of whether or not the
* remaining arguments are valid.
*/
- len = PAGE_ALIGN(len);
if (len = 0)
goto out;
+ /* Careful about overflows.. */
+ len = PAGE_ALIGN(len);
+ if (!len || len > TASK_SIZE) {
+ addr = -EINVAL;
+ goto out;
+ }
+
/*
* Don't permit mappings into unmapped space, the virtual page table of a region,
* or across a region boundary. Note: RGN_MAP_LIMIT is equal to 2^n-PAGE_SIZE
--
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux AG, Maxfeldstraße 5, 90409 Nürnberg, Germany
Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
next reply other threads:[~2004-04-05 16:49 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-04-05 16:49 Andreas Schwab [this message]
2004-04-05 21:12 ` Missing overflow check in mmap David Mosberger
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