From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out162-62-57-49.mail.qq.com (out162-62-57-49.mail.qq.com [162.62.57.49]) (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 829BC7465 for ; Tue, 5 Mar 2024 00:56:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=162.62.57.49 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709600215; cv=none; b=saO/oeIIq0j/uuKg2S9+ZjTfKKqgERGBypHnagvCRj4Qa+FDdCSYBbxHkQr6CQIsyQ4XP3DUlllq409uvCKsamayzZb39MkmGmWvuMHVTgEhvi4BPa0dAG73vaewFXBNc/iRwegriRg6vmmkyWZ05JrnlvYexqabXB5VPcDMe8k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709600215; c=relaxed/simple; bh=8A4tyZ0gAOGQLtCGhqyBPCD2abAB60AjmkhroDUs34c=; h=Message-ID:From:To:Cc:Subject:Date:In-Reply-To:References: MIME-Version; b=sjV8UbE8pk1dMyI9wXjmK6UeTcff//NTTnyuHEH/wWBHBnL9Qn65Li46oYbLwypEXF+HHGNydGWpWUN9Xisv8nSsnAIPd8cO1G00aa4dTypSPVFrsAiBbo/lj4tRCPzkNPqH4x61kLmD6HXAjc3s0gHwTjsRlrBoHE/mw+p4Hgw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com; spf=pass smtp.mailfrom=qq.com; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b=kZEHzXKh; arc=none smtp.client-ip=162.62.57.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=qq.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b="kZEHzXKh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qq.com; s=s201512; t=1709600208; bh=m1jGkAnh193C+1jepoR5r9qSqXCetNMmlr/wrtXENmM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=kZEHzXKhHMFNps1KzHa5waMYg/9qUYxkYPSqJcgAa8vXkNUjOzxpLppXNfBYWbirk /d5nJnQjWCtTC95RmsGdliIbE/7Q/R2gGSgJytXQJK1kBmtfg/FXHCDKYoPxr0v6lD OXDUjuVRR9OM4hqcB2kXHTiJv2Gj4nf1GTgIsXsg= Received: from pek-lxu-l1.wrs.com ([111.198.228.140]) by newxmesmtplogicsvrszb6-0.qq.com (NewEsmtp) with SMTP id E2E2707D; Tue, 05 Mar 2024 08:56:46 +0800 X-QQ-mid: xmsmtpt1709600206tvnaorjvl Message-ID: X-QQ-XMAILINFO: NhpLzBn2I3XwT1tYh3qwEpUlbacKkOr+XyD8Ax/6Omv/onYChOB+4ZY19RMkkw b/ZD1yNbDXfBWypC0MLdgIPAk+j8PrmpIop5NuaFoWTqbQT/Z7IxZaAPzSpHjk3GJM11rayLxGMN 4e28QDHbXM/9sLFKiwsV2KfimA3qqV1v2f8di9+9ugU8UlXY2HCjzf8LpZAkL6JOFeOUhm5u2Y52 Ogn3y+K5DWOPI4FbFN2te4outko3b/UAOsKjCJj85V9tzAsewMIjwcHe+lNbuSTGdw2wOxCclELg oM9GgxPB9oKZCLi4SpM5hZmBsnlcOWjylHMWGU/hgPfY+WLxL7qLcDEQsBEP4D4G3LmqdWNaozCV tt1wAS5UHyRvV+AxHsCfBiRlicjl+YAyxk4LseFHro+250pCTbRWTpcQqDSgBoi7nNvDWP9r9YKn PTMqQ/nUMRSQzv1Nr2qbnO753TKC1haWQQYsJxaEggbia9WEMmWh8huS4HtTvzGfxXnMRCoguwaU 4Q7fehHL6TfGLqacYjT9WX4FJM9d6nUGV6UxIibjHAg6tL9m+t1HIlFQbcI/Z7cylKVOyEH1fS7P 3cNWX0yULebdYK23Z2C3Wb/RpHZrBIZAnUIVtavSv2k/vGfDrmfBkiikYjU7urpWrLJr+gIKmrN3 DS/hMt9KEaq3Zv0aFDB+kRzUg/qCOntQZhTde6AQ397wKavIwW2iWYoKV432rVKobmmxa7k4diJP +G6jSSLBsX9nQf+6YuvwKwvDtGsSFose1cpAqUXkAoscZwo7bXL8srfQ8wn/2f0IFmCaQFW+++PU p4LrQ5uAEJmtpG9AF9IgzMDs2XK6yi5dd4Iyiqc0p55KbgewDJlYsRWEuQofv059DAqJZCAL7nL+ KoVrN4yGC9UX0vgzDUdR2eXrJ7kH0N4iouO0MJaPJLG46b1u293RsyT0lPEWtJ10qPEqevSm35Xz lyIHC2HQZbgGznhn629g== X-QQ-XMRINFO: Nq+8W0+stu50PRdwbJxPCL0= From: Edward Adam Davis To: syzbot+02e64be5307d72e9c309@syzkaller.appspotmail.com Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [fs?] KASAN: null-ptr-deref Write in do_pagemap_cmd Date: Tue, 5 Mar 2024 08:56:47 +0800 X-OQ-MSGID: <20240305005646.2282887-2-eadavis@qq.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <0000000000001bc4a00612d9a7f4@google.com> References: <0000000000001bc4a00612d9a7f4@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit please test null ptr deref in do_pagemap_cmd #syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 3f78ebbb795f..ab28666956d0 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -2510,6 +2510,8 @@ static long do_pagemap_cmd(struct file *file, unsigned int cmd, switch (cmd) { case PAGEMAP_SCAN: + if (!mm) + return -EINVAL; return do_pagemap_scan(mm, arg); default: