Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756683AbbHZI1H (ORCPT ); Wed, 26 Aug 2015 04:27:07 -0400 Received: from e28smtp02.in.ibm.com ([122.248.162.2]:54218 "EHLO e28smtp02.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756503AbbHZI0y (ORCPT ); Wed, 26 Aug 2015 04:26:54 -0400 X-Helo: d28dlp03.in.ibm.com X-MailFrom: aneesh.kumar@linux.vnet.ibm.com X-RcptTo: linux-kernel@vger.kernel.org From: "Aneesh Kumar K.V" To: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, ryabinin.a.a@gmail.com Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, "Aneesh Kumar K.V" Subject: [PATCH V2 09/10] kasan: Prevent deadlock in kasan reporting Date: Wed, 26 Aug 2015 13:56:17 +0530 Message-Id: <1440577578-15813-10-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1440577578-15813-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1440577578-15813-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15082608-0005-0000-0000-0000072C754D Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1968 Lines: 60 We we end up calling kasan_report in real mode, our shadow mapping for even spinlock variable will show poisoned. This will result in us calling kasan_report_error with lock_report spin lock held. To prevent this disable kasan reporting when we are priting error w.r.t kasan. Signed-off-by: Aneesh Kumar K.V --- mm/kasan/report.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 79fbc5d14bd2..82b41eb83e43 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -185,6 +185,10 @@ void kasan_report_error(struct kasan_access_info *info) { unsigned long flags; + /* + * Make sure we don't end up in loop. + */ + kasan_disable_current(); spin_lock_irqsave(&report_lock, flags); pr_err("=================================" "=================================\n"); @@ -194,12 +198,17 @@ void kasan_report_error(struct kasan_access_info *info) pr_err("=================================" "=================================\n"); spin_unlock_irqrestore(&report_lock, flags); + kasan_enable_current(); } void kasan_report_user_access(struct kasan_access_info *info) { unsigned long flags; + /* + * Make sure we don't end up in loop. + */ + kasan_disable_current(); spin_lock_irqsave(&report_lock, flags); pr_err("=================================" "=================================\n"); @@ -212,6 +221,7 @@ void kasan_report_user_access(struct kasan_access_info *info) pr_err("=================================" "=================================\n"); spin_unlock_irqrestore(&report_lock, flags); + kasan_enable_current(); } void kasan_report(unsigned long addr, size_t size, -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/