-stable review patch. If anyone has any objections, please let us know.
---------------------
From: Hugh Dickins <[email protected]>
upstream commit: 05fa199d45c54a9bda7aa3ae6537253d6f097aa9
Tetsuo Handa reports seeing the WARN_ON(current->mm == NULL) in
security_vm_enough_memory(), when do_execve() is touching the
target mm's stack, to set up its args and environment.
Yes, a UMH_NO_WAIT or UMH_WAIT_PROC call_usermodehelper() spawns
an mm-less kernel thread to do the exec. And in any case, that
vm_enough_memory check when growing stack ought to be done on the
target mm, not on the execer's mm (though apart from the warning,
it only makes a slight tweak to OVERCOMMIT_NEVER behaviour).
Reported-by: Tetsuo Handa <[email protected]>
Signed-off-by: Hugh Dickins <[email protected]>
Cc: [email protected]
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---
mm/mmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1571,7 +1571,7 @@ static int acct_stack_growth(struct vm_a
* Overcommit.. This must be the final test, as it will
* update security statistics.
*/
- if (security_vm_enough_memory(grow))
+ if (security_vm_enough_memory_mm(mm, grow))
return -ENOMEM;
/* Ok, everything looks good - let it rip */