From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp153-171.sina.com.cn (smtp153-171.sina.com.cn [61.135.153.171]) (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 9403A4A06 for ; Sun, 7 Sep 2025 08:19:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=61.135.153.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757233209; cv=none; b=LVh/Op0g1A04aZo3HY6Tf0IuI0mlPbs3BJUHBAPAk95isWS18WxaEsag/WNT9RzKUwwGDdN3+d6h2PFUDtFfb2RzNwJJBiu1PuYTCnOcr58m2fVuKSMo/dVcMohNqQjwgHLOu4Y1iGcySPVw6uWLf6/TFibHRcUEqT7fG+vCO1A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757233209; c=relaxed/simple; bh=V96olQLv/535ofNWAFuxNVmILjmmH4lrIWSeji5gY4s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pZGmEYEedFgp1wBcFwnFT2kA1OQl4vW8Shr1fYRdSmO5C8s12l9Ezhy+XQsLHMBiJxXTbcNnbXKf+QUGBAE9BwbCZ6ZZ0k/MqcjkfRabkDW466WmxcFLH23AawZekk2+dB/fRFZ+Qdk8K09zpxfUBh8rCMgAqem3NeBe6uGVpBE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b=ykGAA5n3; arc=none smtp.client-ip=61.135.153.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b="ykGAA5n3" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sina.com; s=201208; t=1757233199; bh=n8vKqjFQuknmoEO1oFEDcCTzvjF6WGIiOaE+9yTEBtE=; h=From:Subject:Date:Message-ID; b=ykGAA5n3oY99Zmtfqx8EAJ1cn31daZEZv3s6gEs0NkoQRy8tgPRQ1d94y3rp2RQpc cWzOwxJlzPf0haO6OBCyJFwFuddEp1fXh00fx+WGmj479uFagr0PsCafGPtChYHI/e 5W1xJIkMqe4YVu8el43RtflBezC0Erx5XzlSnHpU= X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([114.249.58.236]) by sina.com (10.54.253.34) with ESMTP id 68BD402300007646; Sun, 7 Sep 2025 16:19:49 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 5451956292061 X-SMAIL-UIID: 179DE4EA08734E75B9EC59BE00C9F239-20250907-161949-1 From: Hillf Danton To: syzbot Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [block?] general protection fault in bio_iov_iter_get_pages Date: Sun, 7 Sep 2025 16:19:36 +0800 Message-ID: <20250907081937.6583-1-hdanton@sina.com> In-Reply-To: <68bd3027.050a0220.192772.01cc.GAE@google.com> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit > Date: Sun, 07 Sep 2025 00:11:35 -0700 [thread overview] > Hello, > > syzbot found the following issue on: > > HEAD commit: be5d4872e528 Add linux-next specific files for 20250905 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=17896962580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=a726684450a7d788 > dashboard link: https://syzkaller.appspot.com/bug?extid=b253ade8e1751d90a7a9 > compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10496962580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14a98962580000 #syz test --- x/mm/gup.c +++ y/mm/gup.c @@ -2981,6 +2981,7 @@ static int gup_fast_pmd_leaf(pmd_t orig, return 0; } + pages += *nr; *nr += refs; for (; refs; refs--) *(pages++) = page++; @@ -3024,6 +3025,7 @@ static int gup_fast_pud_leaf(pud_t orig, return 0; } + pages += *nr; *nr += refs; for (; refs; refs--) *(pages++) = page++; --