From nobody Sat Feb 7 16:06:16 2026 Received: from out203-205-221-205.mail.qq.com (out203-205-221-205.mail.qq.com [203.205.221.205]) (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 D5989178383 for ; Mon, 19 Aug 2024 14:56:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.205.221.205 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724079375; cv=none; b=JIusz6Ew9X7ql+a0zPr/r1E1JjGvJbUzxMlXzLqmRuoIdOIsMoq8xQ32UK3wNDUjaHOeK2cuVK/55pfcbaPcWamx1C7rA2NhJ0LgF0tRWCYU3zMhNcf+8q7aSR/bdTHmUILtb0cH/V8YDUuW2OYr1GiRucbgLOpsCHYHgdpWTN8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724079375; c=relaxed/simple; bh=GWPj417j8zzHeYmnsGaTHikctCfMEndcS+75h8wmqXc=; h=Message-ID:From:To:Cc:Subject:Date:MIME-Version; b=TWMHL4GoYbNvWGWWnE+Wd4TghxTluzeKNjXXnb/3Rf0OvxCtF4i+ntrn4qduQcAJuxT2CAQmbrvs1U7cPv2gh+T9EtW634wkxBUkr3Lhv5/3g7wBnu55P4xxxpvZJrY0+Y/9zVdtJ9IFTSvv+G1gdwr9OCo5XPCss+uqkBdp5o4= 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=BlRc8/Qi; arc=none smtp.client-ip=203.205.221.205 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="BlRc8/Qi" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qq.com; s=s201512; t=1724079364; bh=oOn6+C2hQUQF0uGoVQm56ZSL+X2MtgUp158lV4Y0SgA=; h=From:To:Cc:Subject:Date; b=BlRc8/Qil9stAK3JclXZ4RSE0V0I/PBzbfODqTZ6u6CxtfuBpQ6M9CLt1kBVvQ6Gn fWUsKUG7RM+FirU9BfeEKrybUqMH+O7JJzX/oIr/epFK0yoH5Mgo8aMbMBxXXHT4fL zzvmpRdT3z4XxGghPx0MfCWvtfGzQ5nyToYE7COk= Received: from localhost.localdomain ([112.64.14.141]) by newxmesmtplogicsvrsza15-1.qq.com (NewEsmtp) with SMTP id D9334C54; Mon, 19 Aug 2024 22:54:19 +0800 X-QQ-mid: xmsmtpt1724079259tzjn25qdr Message-ID: X-QQ-XMAILINFO: M1rD3f8svNznFa8nw2ZJtee8WuQcQdZ1eDyoJ+1xBxhPLUG+CglSkUgcCxQ5s6 dTP/z/8UUee9oVpNiDrVYug9WO4H4X7/NGD+7ZI0RpMXyr87/zIcjJuzZb4Mg3PFWt2SDzGzhWe0 tfhC6S4+QGyWV03ecWmHecQsu9IQImfPSnjO8Jad5CLDXicTL8pcfp6zVYQVXdj+43UgcPESEvRH X2Tftx+h6GA/usF7sOKz5XzLTzNHrjzA3BqkNN2nkQC5nJNb3TFtm+XjY8qzBWzXYI8DU/HFw920 jupo7xycNIPbQHMEmetkm7YBe/JhYOrJnfYOAdZ2e//XQqtxUfA9jmKdh7XhlPjdVZ1R9sfLEM7r 9Qw1cCM67FGQ+xRC1kzTc7A0h+ldvo+0hn79QT39I7dK67NeiUgiTKOVdZax3zrWLwETTn0+urP6 gCQdbbdwx/SAHbatHAeFXkiN3+uYLKEWQZqmej84tQxsrD6DMomiSl9JyiGDneT50AELWxASm5TX JFKIVVDcrcbBVXasigIg2rsdVjmLOIwTRLb4mA7a8yhx2VPlwJ8d7TvuqEYT/BEvKCPWHaijggoa kHPA/tgM+r3vq97mhjH14MMhnGmwKCVFBTt5waBvigaS7e/lTiU1M8D7GiPo/Qm38XoZXmNWdg3P tfowO/phKsNEov2hzfaomR79YEvXTxLwq0sa1iZYn6K377QkRImOwUr5tn+i3hMs9BB1Wun2sUNv DrAp0Mdk+fhJQkbmP20Mz6n+srLNDQDL0vXRe+EMrS7FED7Q/IcoPAbfMyk6eVEJA3NH4lju+uBO 51z2x8iTPh7yPQXC7tAxjtUVd3HDtyRjcB2qN4EPHmtKbK3pUFwad1zgyZU9wFdQ242DScQmpt31 ktY0OfXxNIo0jl5zTN5RdXczd5oRxiVGeik4ueqWnKMmo/BK8hvlggzUy1iJikaP1u7ZV0RF2URL jqso4GFuiKJH9zea7MrGAClyzQXCrN1qB2SH5mWqPy5VWREGbr628YIo8hLiKYwk39NUVjETocPE +1fyIDaRJN0JGLC/gh X-QQ-XMRINFO: OD9hHCdaPRBwq3WW+NvGbIU= From: jiping huang To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, jiping huang Subject: [PATCH] mm: Avoid a risk of null pointer. Date: Mon, 19 Aug 2024 22:54:16 +0800 X-OQ-MSGID: <20240819145416.1504-1-huangjiping95@qq.com> X-Mailer: git-send-email 2.34.1 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" There is a probability that we will get a null pointer when we use find_vm() interface. Signed-off-by: jiping huang diff --git a/mm/mempolicy.c b/mm/mempolicy.c index aec756ae5637..a0bcc1865c62 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1079,6 +1079,11 @@ static long migrate_to_node(struct mm_struct *mm, in= t source, int dest, mmap_read_lock(mm); vma =3D find_vma(mm, 0); =20 + if (!vma) { + mmap_read_unlock(mm); + return -EFAULT; + } + /* * This does not migrate the range, but isolates all pages that * need migration. Between passing in the full user address --=20 2.34.1