From nobody Sat Jul 25 20:08:04 2026 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 580ED3F823E for ; Tue, 14 Jul 2026 08:14:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=124.126.103.232 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784016875; cv=none; b=T0IFxkMh98sNbcaK1OsaZIY6Eh4xT9medLgg+HMUVLKGHOqh6Rm39qWEQBHcq2HC1NDpStZg/wYvrElvqiXFW/MnmmpOdfaaoL1uxLRpy8Y9hNuX/nMZWxd5i0jwyxl+Ur4rmRvSq7mehfJR6P1HGnzDetUMu5WnHgouLbRmrAE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784016875; c=relaxed/simple; bh=vMY+QW+bD/1OoavOtCalWx/LrNcBgetW7nRX0VRhsto=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=ETRoQTZSCzkvoruJQtL+4X/SNjov7G7kuFiVI/ngtCXANSuB7kGPsQJcuKhXCxj/oWSULn4G5eTvW23DNO9reQnGwmjDqEy9pq1VjXNDKSgyiBnVgqPhtb41lCt8elgh/TIWMt5s+WALta4dBSTP8YwP5BYZLPru+RIiyowD988= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=kylinos.cn; arc=none smtp.client-ip=124.126.103.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kylinos.cn X-UUID: 05adc23e7f5c11f1aa26b74ffac11d73-20260714 X-CTIC-Tags: HR_CC_COUNT, HR_CC_DOMAIN_COUNT, HR_CC_NAME, HR_CC_NO_NAME, HR_CTE_8B HR_CTT_MISS, HR_DATE_H, HR_DATE_WKD, HR_DATE_ZONE, HR_FROM_NAME HR_SJ_DIGIT_LEN, HR_SJ_LANG, HR_SJ_LEN, HR_SJ_LETTER, HR_SJ_NOR_SYM HR_SJ_PHRASE, HR_SJ_PHRASE_LEN, HR_SJ_WS, HR_TO_COUNT, HR_TO_DOMAIN_COUNT HR_TO_NO_NAME, IP_TRUSTED, SRC_TRUSTED, DN_TRUSTED, SA_EXISTED SN_EXISTED, SPF_NOPASS, DKIM_NOPASS, DMARC_NOPASS, CIE_GOOD CIE_GOOD_SPF, GTI_FG_BS, GTI_RG_INFO, GTI_C_BU, AMN_GOOD ABX_MISS_RDNS X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.12,REQID:1c751aa5-e02a-4755-9f61-ae73243d78ca,IP:20, URL:0,TC:0,Content:0,EDM:25,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTIO N:release,TS:45 X-CID-INFO: VERSION:1.3.12,REQID:1c751aa5-e02a-4755-9f61-ae73243d78ca,IP:20,UR L:0,TC:0,Content:0,EDM:25,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTION: release,TS:45 X-CID-META: VersionHash:e7bac3a,CLOUDID:dfdd182856bcc302edbee6b71e9bdf3c,BulkI D:260714161426D0BFWHNS,BulkQuantity:0,Recheck:0,SF:17|19|38|66|78|102|127| 850|865|898,TC:nil,Content:0|15|50,EDM:5,IP:-2,URL:0,File:nil,RT:nil,Bulk: nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1,SPR:NO,DKR:0,DKP:0,BRR:0,B RE:0,ARC:0 X-CID-BVR: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_FAS,TF_CID_SPAM_FSD,TF_CID_SPAM_SNR X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: 05adc23e7f5c11f1aa26b74ffac11d73-20260714 X-User: wangxuewen@kylinos.cn Received: from localhost.localdomain [(223.70.159.239)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA with TLSv1.3 TLS_AES_256_GCM_SHA384 256/256) with ESMTP id 327767584; Tue, 14 Jul 2026 16:14:23 +0800 From: Xuewen Wang To: ryabinin.a.a@gmail.com, glider@google.com, andreyknvl@gmail.com, dvyukov@google.com, vincenzo.frascino@arm.com, akpm@linux-foundation.org Cc: kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Xuewen Wang Subject: [PATCH v1] mm/kasan: fix swapped read/write lock usage in stack ring Date: Tue, 14 Jul 2026 16:14:08 +0800 Message-Id: <20260714081408.1596052-1-wangxuewen@kylinos.cn> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The read-write lock semantics for stack_ring.lock are inverted: - save_stack_info() modifies stack ring entries but uses read_lock, which does not protect against concurrent writers and does not block readers from observing partial updates. - kasan_complete_mode_report_info() only reads the stack ring but uses write_lock_irqsave(), which prevents concurrent readers from walking the ring simultaneously. Swap the lock types to match their actual access patterns: - save_stack_info(): read_lock -> write_lock - kasan_complete_mode_report_info(): write_lock -> read_lock Fixes: 7bc0584e5d2a ("kasan: implement stack ring for tag-based modes") Signed-off-by: Xuewen Wang --- mm/kasan/report_tags.c | 4 ++-- mm/kasan/tags.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/mm/kasan/report_tags.c b/mm/kasan/report_tags.c index d15f8f580e2c..62576b1470e1 100644 --- a/mm/kasan/report_tags.c +++ b/mm/kasan/report_tags.c @@ -39,7 +39,7 @@ void kasan_complete_mode_report_info(struct kasan_report_= info *info) return; } =20 - write_lock_irqsave(&stack_ring.lock, flags); + read_lock_irqsave(&stack_ring.lock, flags); =20 pos =3D atomic64_read(&stack_ring.pos); =20 @@ -99,7 +99,7 @@ void kasan_complete_mode_report_info(struct kasan_report_= info *info) } } =20 - write_unlock_irqrestore(&stack_ring.lock, flags); + read_unlock_irqrestore(&stack_ring.lock, flags); =20 /* Assign the common bug type if no entries were found. */ if (!info->bug_type) diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c index d65d48b85f90..6aa09122f09e 100644 --- a/mm/kasan/tags.c +++ b/mm/kasan/tags.c @@ -110,7 +110,7 @@ static void save_stack_info(struct kmem_cache *cache, v= oid *object, * Prevent save_stack_info() from modifying stack ring * when kasan_complete_mode_report_info() is walking it. */ - read_lock_irqsave(&stack_ring.lock, flags); + write_lock_irqsave(&stack_ring.lock, flags); =20 next: pos =3D atomic64_fetch_add(1, &stack_ring.pos); @@ -131,7 +131,7 @@ static void save_stack_info(struct kmem_cache *cache, v= oid *object, =20 entry->ptr =3D object; =20 - read_unlock_irqrestore(&stack_ring.lock, flags); + write_unlock_irqrestore(&stack_ring.lock, flags); =20 if (old_stack) stack_depot_put(old_stack); --=20 2.25.1