[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-Id: <1374456103-25353-2-git-send-email-davidlohr.bueso@hp.com>
Date: Sun, 21 Jul 2013 18:21:40 -0700
From: Davidlohr Bueso <davidlohr.bueso@...com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org,
Davidlohr Bueso <davidlohr.bueso@...com>
Subject: [PATCH 1/4] ipc, shm: guard against non-existant vma in shmdt(2)
When !CONFIG_MMU there's a chance we can derefence a NULL pointer
when the VM area isn't found - check the return value of find_vma().
Also, remove the redundant -EINVAL return: retval is set to the proper
return code and *only* changed to 0, when we actually unmap the segments.
Signed-off-by: Davidlohr Bueso <davidlohr.bueso@...com>
---
ipc/shm.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/ipc/shm.c b/ipc/shm.c
index 59f2194..c7ee2f6 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -1288,8 +1288,7 @@ SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
#else /* CONFIG_MMU */
/* under NOMMU conditions, the exact address to be destroyed must be
* given */
- retval = -EINVAL;
- if (vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
+ if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
retval = 0;
}
--
1.7.11.7
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists