* [Linux-ia64] Security issue with Linux/IA-64
@ 2002-07-09 21:03 Arun Sharma
0 siblings, 0 replies; only message in thread
From: Arun Sharma @ 2002-07-09 21:03 UTC (permalink / raw)
To: linux-ia64
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I found that running the following program as an unprivileged user on
Linux/IA-64 could hang the system.
#include <unistd.h>
#include <sys/mman.h>
int main(int argc, char **argv)
{
munmap( (void *) 0x2000000000000000L, 0x2000000000000000L - 1);
}
The attached patch fixes the problem. We recommend that distributions
pick this up as soon as possible, because of the nature of the problem.
-Arun
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===== include/asm-ia64/pgalloc.h 1.6 vs edited =====
--- 1.6/include/asm-ia64/pgalloc.h Fri Jun 21 16:18:11 2002
+++ edited/include/asm-ia64/pgalloc.h Tue Jul 9 13:55:27 2002
@@ -17,6 +17,7 @@
#include <linux/mm.h>
#include <linux/threads.h>
+#include <linux/compiler.h>
#include <asm/mmu_context.h>
#include <asm/processor.h>
@@ -204,9 +205,15 @@
static inline void
flush_tlb_pgtables (struct mm_struct *mm, unsigned long start, unsigned long end)
{
- if (rgn_index(start) != rgn_index(end))
- printk("flush_tlb_pgtables: can't flush across regions!!\n");
- flush_tlb_range(mm, ia64_thash(start), ia64_thash(end));
+ if (unlikely(end - start >= 1024*1024*1024*1024UL
+ || rgn_index(start) != rgn_index(end - 1)))
+ /*
+ * This condition is very rare and normal applications shouldn't get
+ * here. No attempt has been made to optimize for this case.
+ */
+ flush_tlb_all();
+ else
+ flush_tlb_range(mm, ia64_thash(start), ia64_thash(end));
}
/*
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2002-07-09 21:03 [Linux-ia64] Security issue with Linux/IA-64 Arun Sharma
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