From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E384438D3F1 for ; Thu, 10 Sep 2026 19:08:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789067324; cv=none; b=bks7Ae0M4m+2/e7FU0Fba1yHa4pFmscxszDbPi60s7JjdQbZRuqcJ+eI/pcK0T+LcJ3+avuZIzXgK9kzOkW2UUYnCXDuI3SZUmDuBN2VNWAQUc1Y7jgwl2QJrgx6aNInvdcPnVyVZ4K34wv7Mm5xl0LTyjWs8DXM6NKKW5R6hhg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789067324; c=relaxed/simple; bh=6+C2J2qOjte4O4mB09YJB8xP/tXI53jg9CjBEXp9/Mo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Y8oQiSoOeKcgtlqMsv8vCLjgLLc1pmwISxZD2RpcaHZG76+hf2ATpUWG2UJb3qHj4cOahn5PNaxnT/hdt0vcLYgzjzMLQBisNk13bMZRS390C0M2s7WKPokzhjuszxek5v3nD55L/VwXKTpjSXTsNIopMvEgP9A8iDlmfMfmom8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dnN0w2rw; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="dnN0w2rw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7E90B1F000FF; Thu, 10 Sep 2026 19:08:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789067322; bh=RxCv8qpAoDSLQ4w/Dp7OTvEY9fufgD87yKnFIQKV/EQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=dnN0w2rwTKJ0d9aeG5VmX8RxWsESpWc5zwlaQN16ixR1tck1nzY0D1wcFO6IIEaj+ 2OR8b+cfDKcEAyNSwn4GEqe8rVoXypFZql3Fas18fHGm4Fw5REzri0axZ0uVz4tGvz KtSI8I7fvQhnHp+eRX7PiYI0idYr3V4SyiaBH53dG2TRe+8FBQar5RSVL9XFznFWmB CM8uzsdESKr9a6LwyzQTSp6RpDoGuAZtQ2c5EE+Fy8prlSpv8y9GGEe/Ld9p29RpIG EZOTAM9sJowV8SOoOJgc+yslQWlbkv8RGujzYWtz5sAPnh2Hbk0srGW3Sz4g51YxY7 4yryl+OBCTB3g== From: Sasha Levin To: stable@vger.kernel.org Cc: Hugh Dickins , Catalin Marinas , Alexander Gordeev , Alexandre Ghiti , "Aneesh Kumar K.V" , Christian Borntraeger , Chris Zankel , Claudio Imbrenda , David Hildenbrand , "David S. Miller" , Geert Uytterhoeven , Greg Ungerer , Heiko Carstens , Helge Deller , "H. Peter Anvin" , Ingo Molnar , John David Anglin , John Paul Adrian Glaubitz , "Kirill A. Shutemov" , "Matthew Wilcox (Oracle)" , Max Filippov , Michael Ellerman , Michal Simek , Mike Kravetz , "Mike Rapoport (IBM)" , Palmer Dabbelt , Peter Zijlstra , Qi Zheng , Russell King , Suren Baghdasaryan , Thomas Bogendoerfer , Thomas Gleixner , Will Deacon , Andrew Morton , Sasha Levin Subject: [PATCH 5.15.y 1/2] arm64: allow pte_offset_map() to fail Date: Thu, 10 Sep 2026 15:08:36 -0400 Message-ID: <20260910190837.1453363-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026090941-average-edition-4184@gregkh> References: <2026090941-average-edition-4184@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Hugh Dickins [ Upstream commit 52924726f4c06b3f77de75fb665e6efd8e777d07 ] In rare transient cases, not yet made possible, pte_offset_map() and pte_offset_map_lock() may not find a page table: handle appropriately. Link: https://lkml.kernel.org/r/35e46485-8499-4337-c51f-b8fa495a1a93@google.com Signed-off-by: Hugh Dickins Acked-by: Catalin Marinas Cc: Alexander Gordeev Cc: Alexandre Ghiti Cc: Aneesh Kumar K.V Cc: Christian Borntraeger Cc: Chris Zankel Cc: Claudio Imbrenda Cc: David Hildenbrand Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greg Ungerer Cc: Heiko Carstens Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: John David Anglin Cc: John Paul Adrian Glaubitz Cc: Kirill A. Shutemov Cc: Matthew Wilcox (Oracle) Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Mike Kravetz Cc: Mike Rapoport (IBM) Cc: Palmer Dabbelt Cc: Peter Zijlstra Cc: Qi Zheng Cc: Russell King Cc: Suren Baghdasaryan Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Andrew Morton Stable-dep-of: a77644d009de ("arm64: mm: Fix the lockless page-table walk in show_pte()") Signed-off-by: Sasha Levin --- arch/arm64/mm/fault.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index d293aac8c554c..39f03d18717eb 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -176,6 +176,9 @@ static void show_pte(unsigned long addr) break; ptep = pte_offset_map(pmdp, addr); + if (!ptep) + break; + pte = READ_ONCE(*ptep); pr_cont(", pte=%016llx", pte_val(pte)); pte_unmap(ptep); -- 2.53.0