This is a note to let you know that I've just added the patch titled ipc, shm: guard against non-existant vma in shmdt(2) to the 3.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ipc-shm-guard-against-non-existant-vma-in-shmdt-2.patch and it can be found in the queue-3.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 530fcd16d87cd2417c472a581ba5a1e501556c86 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso <davidlohr.bueso@xxxxxx> Date: Wed, 11 Sep 2013 14:26:28 -0700 Subject: ipc, shm: guard against non-existant vma in shmdt(2) From: Davidlohr Bueso <davidlohr.bueso@xxxxxx> commit 530fcd16d87cd2417c472a581ba5a1e501556c86 upstream. 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@xxxxxx> Cc: Sedat Dilek <sedat.dilek@xxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Mike Galbraith <efault@xxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- ipc/shm.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/ipc/shm.c +++ b/ipc/shm.c @@ -1295,8 +1295,7 @@ SYSCALL_DEFINE1(shmdt, char __user *, sh #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; } Patches currently in stable-queue which might be from davidlohr.bueso@xxxxxx are queue-3.11/ipc-drop-ipc_lock_by_ptr.patch queue-3.11/ipc-msg-drop-msg_unlock.patch queue-3.11/ipc-shm-shorten-critical-region-in-shmctl_down.patch queue-3.11/ipc-rename-ids-rw_mutex.patch queue-3.11/ipc-shm-introduce-lockless-functions-to-obtain-the-ipc-object.patch queue-3.11/ipc-shm-shorten-critical-region-for-shmat.patch queue-3.11/ipc-shm-shorten-critical-region-for-shmctl.patch queue-3.11/ipc-shm-introduce-shmctl_nolock.patch queue-3.11/ipc-drop-ipcctl_pre_down.patch queue-3.11/ipc-document-general-ipc-locking-scheme.patch queue-3.11/ipc-shm-drop-shm_lock_check.patch queue-3.11/ipc-shm-guard-against-non-existant-vma-in-shmdt-2.patch queue-3.11/ipc-shm-cleanup-do_shmat-pasta.patch queue-3.11/ipc-drop-ipc_lock_check.patch queue-3.11/ipc-shm-make-shmctl_nolock-lockless.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html