A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-30 11:41:38 -04:00
Code Issues Projects Releases Packages Wiki Activity

nfsd: fix vm overcommit crash

Browse source 
Junjiro R.  Okajima reported a problem where knfsd crashes if you are
using it to export shmemfs objects and run strict overcommit.  In this
situation the current->mm based modifier to the overcommit goes through a
NULL pointer.

We could simply check for NULL and skip the modifier but we've caught
other real bugs in the past from mm being NULL here - cases where we did
need a valid mm set up (eg the exec bug about a year ago).

To preserve the checks and get the logic we want shuffle the checking
around and add a new helper to the vm_ security wrappers

Also fix a current->mm reference in nommu that should use the passed mm

[[email protected]: coding-style fixes]
[[email protected]: fix build]
Reported-by: Junjiro R. Okajima <[email protected]>
Acked-by: James Morris <[email protected]>
Signed-off-by: Alan Cox <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Alan Cox 2008-10-29 14:01:20 -07:00 • committed by Linus Torvalds
commit 731572d39f
5 changed files with 23 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

3
mm/mmap.c
View file

@ -175,7 +175,8 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
/* Don't let a single process grow too big:
leave 3% of the size of this process for other processes */
allowed -= mm->total_vm / 32;
if (mm)
allowed -= mm->total_vm / 32;
/*
* cast `allowed' as a signed long because vm_committed_space