From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 01E341E0087; Mon, 21 Oct 2024 10:46:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729507589; cv=none; b=D4+B2KlVJohLKP+1Rej/f6H/U7sxAt7jzU8FhV6pCeuJm8cTRxyvzO1aaKtlouylwaSQfgGnDzLRpXBzi81G8SaHCTk7BdFxC4MgPimqytL+o4vlyCPrmRuYRMDbTrt41FwN+foBxu8ciT63Lba7YnNEf6T7/JZfCeP48JIG/dA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729507589; c=relaxed/simple; bh=qzytvI6X6dYy7p2w81r5U/ZElz8EZ4aONiOBsJPLfUA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=jKzbdIxlq3+Hn07nz29wo13LhSRi1h8Tiw2WQvgi3ThDsaByOEpXRi+p04Y5wH8ou1GZuy+hWs4DEeK0L4z/3247GB/mfCz24sXdjHyIqmscD/qG4cK49OiPUbe4NtQZqUuTL+zE8uSGrihyec9f9z25qAdOlQ/pd2V75W+ATa8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TNuTxnKB; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="TNuTxnKB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4AA97C4CEC3; Mon, 21 Oct 2024 10:46:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1729507588; bh=qzytvI6X6dYy7p2w81r5U/ZElz8EZ4aONiOBsJPLfUA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TNuTxnKB7WN9vYFSQmHZ33h9rDDFRG9ZBuSZuTSKfFCLhP0obQBaiKB7pkGv4+gWC 42YT/bDOd3wJLx0ypigJ5zgddmkvoh5azT+bDr5HXOI7DWqUG+3Szfex6qQAmHV+oY YxDZEA0YmIKrjVRyR4eaH4fnj7yqU69OrZpkAZVs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= , Eric Anholt , Rob Herring , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, "Wachowski, Karol" , Jacek Lawrynowicz , Daniel Vetter , Sherry Yang Subject: [PATCH 5.15 35/82] drm/shmem-helper: Fix BUG_ON() on mmap(PROT_WRITE, MAP_PRIVATE) Date: Mon, 21 Oct 2024 12:25:16 +0200 Message-ID: <20241021102248.630465317@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241021102247.209765070@linuxfoundation.org> References: <20241021102247.209765070@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wachowski, Karol commit 39bc27bd688066a63e56f7f64ad34fae03fbe3b8 upstream. Lack of check for copy-on-write (COW) mapping in drm_gem_shmem_mmap allows users to call mmap with PROT_WRITE and MAP_PRIVATE flag causing a kernel panic due to BUG_ON in vmf_insert_pfn_prot: BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags)); Return -EINVAL early if COW mapping is detected. This bug affects all drm drivers using default shmem helpers. It can be reproduced by this simple example: void *ptr = mmap(0, size, PROT_WRITE, MAP_PRIVATE, fd, mmap_offset); ptr[0] = 0; Fixes: 2194a63a818d ("drm: Add library for shmem backed GEM objects") Cc: Noralf Trønnes Cc: Eric Anholt Cc: Rob Herring Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Daniel Vetter Cc: dri-devel@lists.freedesktop.org Cc: # v5.2+ Signed-off-by: Wachowski, Karol Signed-off-by: Jacek Lawrynowicz Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20240520100514.925681-1-jacek.lawrynowicz@linux.intel.com [ Sherry: bp to fix CVE-2024-39497, ignore context change due to missing commit 21aa27ddc582 ("drm/shmem-helper: Switch to reservation lock") ] Signed-off-by: Sherry Yang Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_gem_shmem_helper.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -607,6 +607,9 @@ int drm_gem_shmem_mmap(struct drm_gem_sh return ret; } + if (is_cow_mapping(vma->vm_flags)) + return -EINVAL; + ret = drm_gem_shmem_get_pages(shmem); if (ret) return ret;