From patchwork Wed Feb 12 06:40:02 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qi Zheng X-Patchwork-Id: 13971241 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 E2985C02198 for ; Wed, 12 Feb 2025 06:41:59 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 76D41280014; Wed, 12 Feb 2025 01:41:59 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 71C7B280012; Wed, 12 Feb 2025 01:41:59 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5BE26280014; Wed, 12 Feb 2025 01:41:59 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 3CFED280012 for ; Wed, 12 Feb 2025 01:41:59 -0500 (EST) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id A042B1C8704 for ; Wed, 12 Feb 2025 06:41:58 +0000 (UTC) X-FDA: 83110347516.10.87E9F28 Received: from mail-pl1-f174.google.com (mail-pl1-f174.google.com [209.85.214.174]) by imf05.hostedemail.com (Postfix) with ESMTP id 2108E100002 for ; Wed, 12 Feb 2025 06:41:54 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=bytedance.com header.s=google header.b=Oz++NSio; spf=pass (imf05.hostedemail.com: domain of zhengqi.arch@bytedance.com designates 209.85.214.174 as permitted sender) smtp.mailfrom=zhengqi.arch@bytedance.com; dmarc=pass (policy=quarantine) header.from=bytedance.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1739342516; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=/wBYRdWhtA3egwicLkCU/PTXlbgsejMuWm2eNpqSb/0=; b=hB13I7k2GBugh8q0ySXRbmLbth4W5k3n0wqNLqN+y8P5euOzaMOgxymGAsRL8xnCvQKmcw qOT2TdPfdQ+IThI2jhSvvtRJHyjUaWuYJmA0mzGIogQOWcjnv2SCvE3awfI+/WzposzkgY gWCLqyaCG/U0jSMA4a74wT7V1bvHaEs= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=bytedance.com header.s=google header.b=Oz++NSio; spf=pass (imf05.hostedemail.com: domain of zhengqi.arch@bytedance.com designates 209.85.214.174 as permitted sender) smtp.mailfrom=zhengqi.arch@bytedance.com; dmarc=pass (policy=quarantine) header.from=bytedance.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1739342516; a=rsa-sha256; cv=none; b=KxSz+s0JAPpoP0G9Fpdep/s+WfSCUN6FKIHRDLgq8KH7HzJCTOA1nbRTej0Z40GLarRl9/ jcskPko6hxdLWO3HWddnErK2dR1Yg+xAyojwL6UHawBGvpn505e/qtJEDGNd4J9ywp4r+S HQ/wMXuploAUEzFQhOfUGTh5FMGURdo= Received: by mail-pl1-f174.google.com with SMTP id d9443c01a7336-21f62cc4088so78102885ad.3 for ; Tue, 11 Feb 2025 22:41:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1739342514; x=1739947314; darn=kvack.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=/wBYRdWhtA3egwicLkCU/PTXlbgsejMuWm2eNpqSb/0=; b=Oz++NSio/NcxMb0UfZuKhFCO3ULIZeEYXpWLH9DH9L9WllJvNhUw2jLWvrFkvBeRvk +/k/bJyttmHPYeeEXWzatjXl5REguFiWDVqdgp1/FK7hGxMTsKyn5xdpzpovseQ/3FMC G0Ok+wvAxm55TzIxLMuNIhnHuoJSJZquAdgcxUmplOl1YQZnKc36QKJy/wf9hPWG4rPD UCbLFX/X4rNz5+3nmUhST70e5pc++axpVDhPiXx4EXtmsmkcFLsY88BxPXfyjXgyA9ZT KLeepoM6w9KonJKquxQ1jyeAIU3OtX5jLeOptKSxJtye1If9APAEk+RNSIo+4eZRhiTW 9Zzg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1739342514; x=1739947314; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=/wBYRdWhtA3egwicLkCU/PTXlbgsejMuWm2eNpqSb/0=; b=wDNL9s0N9i3kwCtza9eZymhOqt5yg0gElBrMHploWs1P4gIwrarjTmCQ2dKbzTTc35 /FyG1uWYgG96ORN9UoFVxgaToKmwBqCoEN7h/2Xpv0DrZNMz3c4H5C+Ew76J/IstwXWf Hr4aGhutjUuQDPoxKJmQBl4t6ZNjKTuZI30wR1Zf6c0GlNAVKYf9bYHc7ITLUNOXqYRi 5UGlMDlMbDlfUfGP/ig7W5icpLWt5qyYyRfweSii/9lmp2Jem3+0GpXIuGffLiOU7dXF o69pn39pW+Bie802m2e/rKIGyJHsHgAlLLdjWTwaz3PcXBu5tBbXSsB88Fw3B+pjAY8E DWMg== X-Forwarded-Encrypted: i=1; AJvYcCUQRyBvRg/WmzSa33+yyi75kHi/Sv3OxjbKJNmFHvi8k2ZjztV0EIHp7xygAAPU3ySlZxuHF9OH/Q==@kvack.org X-Gm-Message-State: AOJu0YzQfQXmUDiyTQ1Iy89YDKncEX+jHrC7u8GsSgD9c8d1hLhsWu4m GcEV5TPmTx1g9bWbKp4SeVjhKfarWiVxuXuXFt8r1s0UW6oYn/h4i9GHo5XNR+4= X-Gm-Gg: ASbGnctCE1+LiC7KxjPwUF5hQAwo9tvmlj/LMYsMJ6Gm+jVMYiEeCFCo/9KlDQ5bNQW edzR3LqdOc85Xsa/W8Bi7yIpfEJA64goxj2CDVi27CVVFiB0DWtrOPM3StYZCO189QxkRpRkBYb P3tUNSPOAyp48HKu44KUZKP2InhfZSU8yKvugywYYTt9zibH6kyCKzM2oTpRk8R/yrIXdcAlgVE 5rFEdeqlwwqZyr0IGT2BSJMuyZbphVyoq4OYD2QNrpEkj05KXhBUlWFUUItZpCx1UEWOC4e9Ke3 482mf2v4yPJNpR+llblMEFCLMqYX9waBDeYy5bHqzHAEvN8vGNiNJPGP X-Google-Smtp-Source: AGHT+IH74x3a61arrF/gqeUXfZpntwfiArJQu0CFKJ9o5bTtZZmrBTsZbUPqFZNfhNpXHrSNNu3gxw== X-Received: by 2002:a17:902:e811:b0:21f:45d:21fb with SMTP id d9443c01a7336-220bbac3250mr30288095ad.3.1739342513657; Tue, 11 Feb 2025 22:41:53 -0800 (PST) Received: from C02DW0BEMD6R.bytedance.net ([203.208.167.153]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2fbf9ab0233sm683131a91.44.2025.02.11.22.41.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 11 Feb 2025 22:41:53 -0800 (PST) From: Qi Zheng To: linux@armlinux.org.uk, ezra@easyb.ch, david@redhat.com, hughd@google.com, ryan.roberts@arm.com, akpm@linux-foundation.org, muchun.song@linux.dev Cc: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Qi Zheng , stable@vger.kernel.org Subject: [PATCH] arm: pgtable: fix NULL pointer dereference issue Date: Wed, 12 Feb 2025 14:40:02 +0800 Message-Id: <20250212064002.55598-1-zhengqi.arch@bytedance.com> X-Mailer: git-send-email 2.24.3 (Apple Git-128) In-Reply-To: References: MIME-Version: 1.0 X-Rspamd-Queue-Id: 2108E100002 X-Stat-Signature: oxtzw84x7yta7b7x8ojsxuingdernq9x X-Rspam-User: X-Rspamd-Server: rspam01 X-HE-Tag: 1739342514-138189 X-HE-Meta: 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 oPfqUHha r/XzfHnl8CmEY5XKsN33eFnkL37KdIAWYelm5/PnrMNNIRgHKgGO18SY6Xeq2TvdYVPpriJign1WgQPnx4AneJP5IKibkxZuizioHhe5K5W4QauteIDI37XeEeLTy88AgCc2TwEkSVViNGtDDtgzNZoxCyYZk08ymmWhZoF6vRmVx2t8+cdtNhh1G2CsOFCixyW3RZbbeYHOj5pDkW8tdU3Hd2YFGs2NutzWvI+T27b6ElkrDuUGaXI4KRGe+6hVHmnVtgi8F4T37LxcvSySYM3l/M5JZnTQmxlwaF0qyvEA0FmFuSm3okHpnT3Vrf0VrN2yFjzYROxraDir53n8oZ7j99a8yAJRdxzT7khZgqMg9d8o= 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: When update_mmu_cache_range() is called by update_mmu_cache(), the vmf parameter is NULL, which will cause a NULL pointer dereference issue in adjust_pte(): Unable to handle kernel NULL pointer dereference at virtual address 00000030 when read Hardware name: Atmel AT91SAM9 PC is at update_mmu_cache_range+0x1e0/0x278 LR is at pte_offset_map_rw_nolock+0x18/0x2c Call trace: update_mmu_cache_range from remove_migration_pte+0x29c/0x2ec remove_migration_pte from rmap_walk_file+0xcc/0x130 rmap_walk_file from remove_migration_ptes+0x90/0xa4 remove_migration_ptes from migrate_pages_batch+0x6d4/0x858 migrate_pages_batch from migrate_pages+0x188/0x488 migrate_pages from compact_zone+0x56c/0x954 compact_zone from compact_node+0x90/0xf0 compact_node from kcompactd+0x1d4/0x204 kcompactd from kthread+0x120/0x12c kthread from ret_from_fork+0x14/0x38 Exception stack(0xc0d8bfb0 to 0xc0d8bff8) To fix it, do not rely on whether 'ptl' is equal to decide whether to hold the pte lock, but decide it by whether CONFIG_SPLIT_PTE_PTLOCKS is enabled. In addition, if two vmas map to the same PTE page, there is no need to hold the pte lock again, otherwise a deadlock will occur. Just add the need_lock parameter to let adjust_pte() know this information. Reported-by: Ezra Buehler Closes: https://lore.kernel.org/lkml/CAM1KZSmZ2T_riHvay+7cKEFxoPgeVpHkVFTzVVEQ1BO0cLkHEQ@mail.gmail.com/ Fixes: fc9c45b71f43 ("arm: adjust_pte() use pte_offset_map_rw_nolock()") Cc: stable@vger.kernel.org Signed-off-by: Qi Zheng --- arch/arm/mm/fault-armv.c | 40 ++++++++++++++++++++++++++++------------ 1 file changed, 28 insertions(+), 12 deletions(-) diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c index 2bec87c3327d2..3627bf0957c75 100644 --- a/arch/arm/mm/fault-armv.c +++ b/arch/arm/mm/fault-armv.c @@ -62,7 +62,7 @@ static int do_adjust_pte(struct vm_area_struct *vma, unsigned long address, } static int adjust_pte(struct vm_area_struct *vma, unsigned long address, - unsigned long pfn, struct vm_fault *vmf) + unsigned long pfn, bool need_lock) { spinlock_t *ptl; pgd_t *pgd; @@ -99,12 +99,11 @@ static int adjust_pte(struct vm_area_struct *vma, unsigned long address, if (!pte) return 0; - /* - * If we are using split PTE locks, then we need to take the page - * lock here. Otherwise we are using shared mm->page_table_lock - * which is already locked, thus cannot take it. - */ - if (ptl != vmf->ptl) { + if (need_lock) { + /* + * Use nested version here to indicate that we are already + * holding one similar spinlock. + */ spin_lock_nested(ptl, SINGLE_DEPTH_NESTING); if (unlikely(!pmd_same(pmdval, pmdp_get_lockless(pmd)))) { pte_unmap_unlock(pte, ptl); @@ -114,7 +113,7 @@ static int adjust_pte(struct vm_area_struct *vma, unsigned long address, ret = do_adjust_pte(vma, address, pfn, pte); - if (ptl != vmf->ptl) + if (need_lock) spin_unlock(ptl); pte_unmap(pte); @@ -123,16 +122,17 @@ static int adjust_pte(struct vm_area_struct *vma, unsigned long address, static void make_coherent(struct address_space *mapping, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep, unsigned long pfn, - struct vm_fault *vmf) + unsigned long addr, pte_t *ptep, unsigned long pfn) { struct mm_struct *mm = vma->vm_mm; struct vm_area_struct *mpnt; unsigned long offset; + unsigned long start; pgoff_t pgoff; int aliases = 0; pgoff = vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT); + start = ALIGN_DOWN(addr, PMD_SIZE); /* * If we have any shared mappings that are in the same mm @@ -141,6 +141,14 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma, */ flush_dcache_mmap_lock(mapping); vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) { + unsigned long mpnt_addr; + /* + * If we are using split PTE locks, then we need to take the pte + * lock. Otherwise we are using shared mm->page_table_lock which + * is already locked, thus cannot take it. + */ + bool need_lock = IS_ENABLED(CONFIG_SPLIT_PTE_PTLOCKS); + /* * If this VMA is not in our MM, we can ignore it. * Note that we intentionally mask out the VMA @@ -151,7 +159,15 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma, if (!(mpnt->vm_flags & VM_MAYSHARE)) continue; offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT; - aliases += adjust_pte(mpnt, mpnt->vm_start + offset, pfn, vmf); + mpnt_addr = mpnt->vm_start + offset; + /* + * If mpnt_addr and addr are mapped to the same PTE page, there + * is no need to hold the pte lock again, otherwise a deadlock + * will occur. + */ + if (mpnt_addr >= start && mpnt_addr - start < PMD_SIZE) + need_lock = false; + aliases += adjust_pte(mpnt, mpnt_addr, pfn, need_lock); } flush_dcache_mmap_unlock(mapping); if (aliases) @@ -194,7 +210,7 @@ void update_mmu_cache_range(struct vm_fault *vmf, struct vm_area_struct *vma, __flush_dcache_folio(mapping, folio); if (mapping) { if (cache_is_vivt()) - make_coherent(mapping, vma, addr, ptep, pfn, vmf); + make_coherent(mapping, vma, addr, ptep, pfn); else if (vma->vm_flags & VM_EXEC) __flush_icache_all(); }