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authorJiri Kosina <jkosina@suse.cz>2008-02-06 22:39:44 +0100
committerIngo Molnar <mingo@elte.hu>2008-02-06 22:39:44 +0100
commit4cc6028d4040f95cdb590a87db478b42b8be0508 (patch)
tree9b9879d8b8cc055e4bb8eabd69b979a17e6e52cd
parent2d684cd6d9cf0c6a0e28978362671b6e2d8fb56c (diff)
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>
-rw-r--r--mm/mmap.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index bb4c963cc534..ad6e4eaf34f8 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -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;
/*