Hello!
On 08.08.2019 9:17, Alexandre Ghiti wrote:
This commit simply bumps up to 32MB and 1GB the random offset
of brk, compared to 8MB and 256MB, for 32bit and 64bit respectively.
Suggested-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Alexandre Ghiti <alex@xxxxxxxx>
Acked-by: Paul Burton <paul.burton@xxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
---
arch/mips/mm/mmap.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c
index a7e84b2e71d7..ff6ab87e9c56 100644
--- a/arch/mips/mm/mmap.c
+++ b/arch/mips/mm/mmap.c
[...]
@@ -189,11 +190,11 @@ static inline unsigned long brk_rnd(void)
unsigned long rnd = get_random_long();
rnd = rnd << PAGE_SHIFT;
- /* 8MB for 32bit, 256MB for 64bit */
+ /* 32MB for 32bit, 1GB for 64bit */
if (TASK_IS_32BIT_ADDR)
- rnd = rnd & 0x7ffffful;
+ rnd = rnd & (SZ_32M - 1);
else
- rnd = rnd & 0xffffffful;
+ rnd = rnd & (SZ_1G - 1);
Why not make these 'rnd &= SZ_* - 1', while at it anyways?
[...]
MBR, Sergei
