[PATCH] prctl: fix validation of an address

From: Andrey Vagin
Date: Sat Dec 29 2012 - 06:01:38 EST


The address should be bigger than dac_mmap_min_addr, because
a process with CAP_RAWIO can map a vma bellow mmap_min_addr.

Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Cc: Serge Hallyn <serge.hallyn@xxxxxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Eric Paris <eparis@xxxxxxxxxx>
Cc: James Morris <jmorris@xxxxxxxxx>
Signed-off-by: Andrey Vagin <avagin@xxxxxxxxxx>
---
kernel/sys.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sys.c b/kernel/sys.c
index 265b376..e0e1bbd 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1868,7 +1868,7 @@ static int prctl_set_mm(int opt, unsigned long addr,
if (opt == PR_SET_MM_EXE_FILE)
return prctl_set_mm_exe_file(mm, (unsigned int)addr);

- if (addr >= TASK_SIZE || addr < mmap_min_addr)
+ if (addr >= TASK_SIZE || addr < dac_mmap_min_addr)
return -EINVAL;

error = -EINVAL;
--
1.7.11.7

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