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 DC8C43C454F for ; Tue, 22 Sep 2026 15:09:19 +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=1790089762; cv=none; b=V/PFvmECFO78dLM1E9VuLDIFS34O2FirqNRBk0qRM8vWSPobUPm7u6jDFv2fdYo9tyFrw1TA2soJZJOWwvSOpisrkhu9zAoInjOtFFLkTx7WDhwt0N8DAml5kBveqMRa5CJMJO5xdbN8qX3LNCGHYzY5fwVd5mVbY0zDBQ0xuT0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790089762; c=relaxed/simple; bh=abKNX7cqlpAcks9ykFNkY65VMoj5EatSU0FIkanjUr4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EpztDHVpAU9G0t5B4y99rxtEm4WZXKnVASYlnZiO428nJH/NAUGMOFNmmK2GnPsaXn6nbX+P19JekN+rCBXuBK3B2UfC+/wPDbf3ByKjghKEMLDkWoNGabt2YSbfcThu9cKlNMTF7pZFS3hdH0i+4+vCS26QU33eQl6Q3qjZOFQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kCizMDu/; 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="kCizMDu/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4610E1F000FF; Tue, 22 Sep 2026 15:09:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790089756; bh=RpxJA4hiRcSAGpVZ7kP2DheoSiv3zHhW5sfbqzzWrqM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=kCizMDu/3jIF/Qz58zT2Gcb5ou1KeJ6Zu7JIB8rth0kho2n4PSgqio/6VJxINq3ik uA4M8W1+wqUkVLU61CFwfryvFaG0zscLbMC5XZ/vEn7PgscYUESkjiVsb6IGK4+N08 0PpAJMegTszMF0mUZ6qT0kAlNpVBetExcIbzPTFquGat5qj1tWwafrDre8DyJTDC+Z uFOM0XvGb24Syj2I3ja12jn6zR/uQTeX+A07I3Bd3hBop6K0gpzi+iiXHeObkcfa1R iVC9dirdNYOJuajSoPtHETBV5waixMjlvagx/brCw44+X4z4CgT3ihlJHz8yS9vNEl J1eZO0NZ6GnjQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Donggeun Yoo , Michael Kelley , Marek Szyprowski , Sasha Levin Subject: [PATCH 6.6.y] swiotlb: use the adjusted address for the highmem page lookup Date: Tue, 22 Sep 2026 11:09:14 -0400 Message-ID: <20260922150914.2750787-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026092245-shallot-entrap-77a4@gregkh> References: <2026092245-shallot-entrap-77a4@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: Donggeun Yoo [ Upstream commit b7d7914a9ae3097e63d113007e4fb44d33d515b1 ] swiotlb_bounce() reads the page frame number from the slot's recorded orig_addr, then advances orig_addr by tlb_offset to reach the address the caller asked about. The highmem branch mixes the two: the offset within the page comes from the adjusted address, the page from the value before it. Once the adjustment crosses a page boundary the pair no longer describes one location, and the whole copy lands one page below the intended one for a positive tlb_offset, one above for a negative one. DMA_FROM_DEVICE writes the device data over the wrong page and leaves the intended one stale, DMA_TO_DEVICE feeds the device from a page the mapping may not cover. Partial syncs through dma_sync_single_range_for_*() are what make tlb_offset non-zero. The branch test is picked the same way, so a slot recorded in lowmem can be adjusted into highmem and the lowmem path then hands a highmem address to phys_to_virt(). Take both from orig_addr once it is final and keep pfn in the branch that uses it. PhysHighMem() asks the question straight from the address, as dma-debug already does. Fixes: 5f89468e2f06 ("swiotlb: manipulate orig_addr when tlb_addr has offset") Cc: stable@vger.kernel.org Signed-off-by: Donggeun Yoo Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20260905084210.148255-1-donggeunyoo.kernel@gmail.com Signed-off-by: Marek Szyprowski [ replaced unavailable PhysHighMem(orig_addr) with PageHighMem(pfn_to_page(PFN_DOWN(orig_addr))). ] Signed-off-by: Sasha Levin --- kernel/dma/swiotlb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 0968155a638e3..d615d2ec47bae 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -868,7 +868,6 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size int index = (tlb_addr - mem->start) >> IO_TLB_SHIFT; phys_addr_t orig_addr = mem->slots[index].orig_addr; size_t alloc_size = mem->slots[index].alloc_size; - unsigned long pfn = PFN_DOWN(orig_addr); unsigned char *vaddr = mem->vaddr + tlb_addr - mem->start; unsigned int tlb_offset, orig_addr_offset; @@ -902,7 +901,8 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size size = alloc_size; } - if (PageHighMem(pfn_to_page(pfn))) { + if (PageHighMem(pfn_to_page(PFN_DOWN(orig_addr)))) { + unsigned long pfn = PFN_DOWN(orig_addr); unsigned int offset = orig_addr & ~PAGE_MASK; struct page *page; unsigned int sz = 0; -- 2.53.0