Re: [PATCH v6 11/14] mips: Adjust brk randomization offset to fit generic version

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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



[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]

  Powered by Linux