From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp3-g21.free.fr (smtp3-g21.free.fr [212.27.42.3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3xp5RJ12D8zDrWN for ; Fri, 8 Sep 2017 02:25:48 +1000 (AEST) From: Laurent Dufour To: benh@kernel.crashing.org, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH] powerpc/mm: Fix missing mmap_sem release Date: Thu, 7 Sep 2017 18:25:29 +0200 Message-Id: <1504801529-15113-1-git-send-email-laurent.du4@free.fr> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , The commit b5c8f0fd595d ("powerpc/mm: Rework mm_fault_error()") reviewed the way the error path is managed in __do_page_fault() but it was a bit too agressive when handling a case by returning without releasing the mmap_sem. By the way, replacing current->mm->mmap_sem by mm->mmap_sem as mm is set to current->mm. Fixes: b5c8f0fd595d ("powerpc/mm: Rework mm_fault_error()") Cc: Benjamin Herrenschmidt Signed-off-by: Laurent Dufour --- arch/powerpc/mm/fault.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 4797d08581ce..f799ccf37d27 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -521,10 +521,11 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, * User mode? Just return to handle the fatal exception otherwise * return to bad_page_fault */ + up_read(&mm->mmap_sem); return is_user ? 0 : SIGBUS; } - up_read(¤t->mm->mmap_sem); + up_read(&mm->mmap_sem); if (unlikely(fault & VM_FAULT_ERROR)) return mm_fault_error(regs, address, fault); -- 2.7.4