From patchwork Fri Feb 21 01:50:56 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tong Tiangen X-Patchwork-Id: 13984747 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id B35CCC021B2 for ; Fri, 21 Feb 2025 01:51:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 29E416B00A1; Thu, 20 Feb 2025 20:51:26 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 232706B00A3; Thu, 20 Feb 2025 20:51:26 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0F004280014; Thu, 20 Feb 2025 20:51:26 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id E0B3B6B00B8 for ; Thu, 20 Feb 2025 20:51:25 -0500 (EST) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 9BCCC4B4C6 for ; Fri, 21 Feb 2025 01:51:25 +0000 (UTC) X-FDA: 83142274530.08.240E158 Received: from szxga07-in.huawei.com (szxga07-in.huawei.com [45.249.212.35]) by imf03.hostedemail.com (Postfix) with ESMTP id 71CCA20006 for ; Fri, 21 Feb 2025 01:51:22 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf03.hostedemail.com: domain of tongtiangen@huawei.com designates 45.249.212.35 as permitted sender) smtp.mailfrom=tongtiangen@huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1740102683; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding:in-reply-to: references; bh=U/JckgyJQKuS1Pu0D+vZEhXheh8PQaT/XBX9PUzP6aI=; b=RWxd+H2Bcdnp4qMERVs8vpndpIRERSSJ+XRXs0k8icotMJS2sK+3v/PT1DJKGUCP+g2L5n f1vGKV5bGbuXNZjZdssk3hYCH8Plr5i2tQT/J+YbfPIQISyxN+0/Fkf1Awwl4GgCvhzMLw USC897VO+IP42vcXGXbZU6Bwbp9PvtU= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1740102683; a=rsa-sha256; cv=none; b=vHhZnB+ketQX62KlzH2KhjpOKwLHuIqdimyOSc83MRLIerNWM2rbxZUdwcRiKOiBdt8vCR Ead4SJmALEDMawmtwy5i6RwSoAkj4sgUFQ5dvBugM0iz9nPRCgN1aPGwY+xINFwMjakN/p C37FnMwJgW6M73oufzfB2QfDXMVEvaw= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf03.hostedemail.com: domain of tongtiangen@huawei.com designates 45.249.212.35 as permitted sender) smtp.mailfrom=tongtiangen@huawei.com Received: from mail.maildlp.com (unknown [172.19.88.163]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4YzY0R1gvXz1wn7R; Fri, 21 Feb 2025 09:47:19 +0800 (CST) Received: from kwepemk500005.china.huawei.com (unknown [7.202.194.90]) by mail.maildlp.com (Postfix) with ESMTPS id A8D8B18001B; Fri, 21 Feb 2025 09:51:16 +0800 (CST) Received: from localhost.localdomain (10.175.112.125) by kwepemk500005.china.huawei.com (7.202.194.90) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 21 Feb 2025 09:51:15 +0800 From: Tong Tiangen To: David Hildenbrand , Oleg Nesterov , Andrew Morton , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Peter Xu , Ian Rogers , Adrian Hunter , "Liang, Kan" , Masami Hiramatsu CC: , , , , , Tong Tiangen , , Guohanjun Subject: [PATCH -next v2] uprobes: fix two zero old_folio bugs in __replace_page() Date: Fri, 21 Feb 2025 09:50:56 +0800 Message-ID: <20250221015056.1269344-1-tongtiangen@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.175.112.125] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemk500005.china.huawei.com (7.202.194.90) X-Rspam-User: X-Rspamd-Queue-Id: 71CCA20006 X-Rspamd-Server: rspam07 X-Stat-Signature: ym17ytogfk9qqfiyh1baaarwfr7ncbss X-HE-Tag: 1740102682-271882 X-HE-Meta: U2FsdGVkX1/oO8f88Lo0rgbw0+eItraLuuK0ZK4iTxj50lB1CzGZX4rA+OEEEs6ORufky2yhFJaEhKABH1tMZpz8zjTwdqomc3wjZh8slxg46fAcmQSvPBoFPjJDKyYiJPKRz6xQRzlETFcPGVj7bw211Pdt1QUpYehvduJqsjsq0fOQF/C165YXZQNfa1u/GylV+Prgj8NsbONtWZy/v/qfyRBiqeonFa/5G7mNzWmYntxs/NdmvvZBMqGihpTQEy45PJaOMXPhC4IAj1iwIMzAevLhmO6mH1QCla3mc8rdSmK9TBZtWRD3kUCNGJ5dODWNIsoNJh+Eq/R86EyrjDaJEAPmevCqVFtgjHDOkJHIq+ieCOyU8/7rmfQz4TKK7OAFuKhJJt5IC55EucZQsvxqDOGFgx5BiGwCghMA3TGeSNvkUspr9dhhvXoAS7i1UBKDfEwPX41ciKDFwW0Mjl/sV8GdNuSlBCPX4qteCNYXqqqrTgq978wDhnCWJgWDHlnZSlR1p0+0o/dKQznVG9n1hopIdM2HthKsQDMqwG8kwguYSlR7DtjgE7nBujsMXKqmTAS0z2cFFewbwo4lM61sIjm0eHQRWdZqj/cUE++F9nQqxVmyYUh3B38KqdsIx3WEKSb+eErsNm1gXJFBZ1/9FXp5fYR9lawMEpYj11PrEYfBPX+m6JduFrne8+jBoAun1Hr6heHhkMkvROopZEDfKa1Hxz5i/SmnDTsraHodcm/C8e9knne6KXqNtHurlIUNlyIdvs4tEtRaO475iX5kOLfHQF/d4KtzMrJ5lhDkPfx3Wcaw63bYqrXXfn3khVQ6lMaGYnURYwXoYcPsgd016/aFXGn+SzpSnvXUd+7aifnPR2Kg/NJ/mrqOSBChy/1SVHqPahjkbfza+zOg4fKXmCv04IYyQ52SXma/zi6Yuu/ao0cNWdTClnLg5cYMsVMB+pyIJQoZkddbguX Q9DgJp8t kKJGbpcPVrLjTsHQPoSFljgFWWyNY2m5ObYXgF7EeakiMCbQ66IgRyJ3MCN+A4QTtKiPA7JcHQ3m1n+DbsMnlczuvZFzXvd0TJkr9IuaHUO7tIIGF9jzcAFXwNJOhFPfgDzvuoahC9/67UvJETN0iAbBCQQGu5aFRIW0VfVp5yfBwQ0i+u1ndiNIsc7erRdA8/p/3aKgR59mkz83aHFJ5cZEB0g== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: We triggered the following error logs in syzkaller test: BUG: Bad page state in process syz.7.38 pfn:1eff3 page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1eff3 flags: 0x3fffff00004004(referenced|reserved|node=0|zone=1|lastcpupid=0x1fffff) raw: 003fffff00004004 ffffe6c6c07bfcc8 ffffe6c6c07bfcc8 0000000000000000 raw: 0000000000000000 0000000000000000 00000000fffffffe 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: dump_stack_lvl+0x32/0x50 bad_page+0x69/0xf0 free_unref_page_prepare+0x401/0x500 free_unref_page+0x6d/0x1b0 uprobe_write_opcode+0x460/0x8e0 install_breakpoint.part.0+0x51/0x80 register_for_each_vma+0x1d9/0x2b0 __uprobe_register+0x245/0x300 bpf_uprobe_multi_link_attach+0x29b/0x4f0 link_create+0x1e2/0x280 __sys_bpf+0x75f/0xac0 __x64_sys_bpf+0x1a/0x30 do_syscall_64+0x56/0x100 entry_SYSCALL_64_after_hwframe+0x78/0xe2 BUG: Bad rss-counter state mm:00000000452453e0 type:MM_FILEPAGES val:-1 The following syzkaller test case can be used to reproduce: r2 = creat(&(0x7f0000000000)='./file0\x00', 0x8) write$nbd(r2, &(0x7f0000000580)=ANY=[], 0x10) r4 = openat(0xffffffffffffff9c, &(0x7f0000000040)='./file0\x00', 0x42, 0x0) mmap$IORING_OFF_SQ_RING(&(0x7f0000ffd000/0x3000)=nil, 0x3000, 0x0, 0x12, r4, 0x0) r5 = userfaultfd(0x80801) ioctl$UFFDIO_API(r5, 0xc018aa3f, &(0x7f0000000040)={0xaa, 0x20}) r6 = userfaultfd(0x80801) ioctl$UFFDIO_API(r6, 0xc018aa3f, &(0x7f0000000140)) ioctl$UFFDIO_REGISTER(r6, 0xc020aa00, &(0x7f0000000100)={{&(0x7f0000ffc000/0x4000)=nil, 0x4000}, 0x2}) ioctl$UFFDIO_ZEROPAGE(r5, 0xc020aa04, &(0x7f0000000000)={{&(0x7f0000ffd000/0x1000)=nil, 0x1000}}) r7 = bpf$PROG_LOAD(0x5, &(0x7f0000000140)={0x2, 0x3, &(0x7f0000000200)=ANY=[@ANYBLOB="1800000000120000000000000000000095"], &(0x7f0000000000)='GPL\x00', 0x7, 0x0, 0x0, 0x0, 0x0, '\x00', 0x0, @fallback=0x30, 0xffffffffffffffff, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x10, 0x0, @void, @value}, 0x94) bpf$BPF_LINK_CREATE_XDP(0x1c, &(0x7f0000000040)={r7, 0x0, 0x30, 0x1e, @val=@uprobe_multi={&(0x7f0000000080)='./file0\x00', &(0x7f0000000100)=[0x2], 0x0, 0x0, 0x1}}, 0x40) The cause is that zero pfn is set to the pte without increasing the rss count in mfill_atomic_pte_zeropage() and the refcount of zero folio does not increase accordingly. Then, the operation on the same pfn is performed in uprobe_write_opcode()->__replace_page() to unconditional decrease the rss count and old_folio's refcount. Therefore, two bugs are introduced: 1. The rss count is incorrect, when process exit, the check_mm() report error "Bad rss-count". 2. The reserved folio (zero folio) is freed when folio->refcount is zero, then free_pages_prepare->free_page_is_bad() report error "Bad page state". Considering that uprobe hit the zero folio is a very rare scene, just reject zero old folio immediately after get_user_page_vma_remote(). Fixes: 7396fa818d62 ("uprobes/core: Make background page replacement logic account for rss_stat counters") Fixes: 2b1444983508 ("uprobes, mm, x86: Add the ability to install and remove uprobes breakpoints") Signed-off-by: Tong Tiangen Reviewed-by: David Hildenbrand Reviewed-by: Oleg Nesterov --- v2: Modified according to the comments of David and Oleg. --- kernel/events/uprobes.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 46ddf3a2334d..daa46868faf3 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -506,6 +506,11 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, if (ret <= 0) goto put_old; + if (is_zero_page(old_page)) { + ret = -EINVAL; + goto put_old; + } + if (WARN(!is_register && PageCompound(old_page), "uprobe unregister should never work on compound page\n")) { ret = -EINVAL;