Commit 4cc6028d authored Feb 06, 2008 by Jiri Kosina Committed by Ingo Molnar Feb 06, 2008

brk: check the lower bound properly



There is a check in sys_brk(), that tries to make sure that we do not
underflow the area that is dedicated to brk heap.

The check is however wrong, as it assumes that brk area starts immediately
after the end of the code (+bss), which is wrong for example in
environments with randomized brk start. The proper way is to check whether
the address is not below the start_brk address.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 2d684cd6

mm/mmap.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -245,7 +245,7 @@ asmlinkage unsigned long sys_brk(unsigned long brk)

		down_write(&mm->mmap_sem);

		if (brk < mm->end_code)
		if (brk < mm->start_brk)
		goto out;

		/*

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