[PATCH 2/3] uprobes: Change valid_vma() to demand VM_MAYEXECrather than VM_EXEC

From: Oleg Nesterov
Date: Sun Sep 16 2012 - 13:51:08 EST


uprobe_register() or uprobe_mmap() requires VM_READ | VM_EXEC, this
is not right. An apllication can do mprotect(PROT_EXEC) later and
execute this code.

Change valid_vma(is_register => true) to check VM_MAYEXEC instead.
No need to check VM_MAYREAD, it is always set.

Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
---
kernel/events/uprobes.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index fa1579a..b9b50dd 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -106,8 +106,8 @@ static bool valid_vma(struct vm_area_struct *vma, bool is_register)
if (!is_register)
return true;

- if ((vma->vm_flags & (VM_HUGETLB|VM_READ|VM_WRITE|VM_EXEC|VM_SHARED))
- == (VM_READ|VM_EXEC))
+ if ((vma->vm_flags & (VM_HUGETLB | VM_WRITE | VM_MAYEXEC | VM_SHARED))
+ == VM_MAYEXEC)
return true;

return false;
--
1.5.5.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/