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From: Daniel Micay <danielmicay@gmail.com>
To: musl@lists.openwall.com
Cc: Daniel Micay <danielmicay@gmail.com>
Subject: [PATCH] prevent allocs than PTRDIFF_MAX via mremap
Date: Sat, 31 Oct 2015 05:14:45 -0400	[thread overview]
Message-ID: <1446282885-5290-1-git-send-email-danielmicay@gmail.com> (raw)

It's quite feasible for this to happen via MREMAP_MAYMOVE.
---
 src/mman/mremap.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/mman/mremap.c b/src/mman/mremap.c
index 596c45f..1096ace 100644
--- a/src/mman/mremap.c
+++ b/src/mman/mremap.c
@@ -1,5 +1,7 @@
 #include <unistd.h>
 #include <sys/mman.h>
+#include <errno.h>
+#include <stdint.h>
 #include <stdarg.h>
 #include "syscall.h"
 #include "libc.h"
@@ -8,7 +10,12 @@ void *__mremap(void *old_addr, size_t old_len, size_t new_len, int flags, ...)
 {
 	va_list ap;
 	void *new_addr;
-	
+
+	if (new_len >= PTRDIFF_MAX) {
+		errno = ENOMEM;
+		return MAP_FAILED;
+	}
+
 	va_start(ap, flags);
 	new_addr = va_arg(ap, void *);
 	va_end(ap);
-- 
2.6.2



             reply	other threads:[~2015-10-31  9:14 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-31  9:14 Daniel Micay [this message]
2015-10-31  9:20 ` Daniel Micay
2015-10-31 20:30   ` Rich Felker
2015-11-02 21:46     ` Rich Felker

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