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 A8513143757; Wed, 19 Jun 2024 13:23:26 +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=1718803406; cv=none; b=BlBgzhbTfYCtEpSmiwxzq3XTUwd1TXiiH38THDBBGA/PSM4C4ls3yQkoD136qD1aozpEUhG/08xEEItIWUvhQ05ql2szYOSKQBZUmRfvzYLX+wJK+AJTobHvXpwlSkJku7sby1epHIWRCW21Vhah6sl8FYIEoch3NqIY+FNvKog= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718803406; c=relaxed/simple; bh=ycFEkXDl6y1C0l2RytQLpK194U5NA3UpzsP2SnMdgTY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=HmQ4oa4klGrqZjQqm5ocZ1zS50ocu0TM7y3AjR/+EVE2JBO13y2K34VVlBZyKdmIany2OoECBfrFVNZ0lCoJc4Bv4X2yN2N7KdYDLP/VbEXH7VmgzDIjn3YrXd84labQEJO1p2K1z/AtGjXC9sBSU3cAW7mduxPN9tOL/AC7nwk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fuR9pA8T; 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="fuR9pA8T" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F349CC2BBFC; Wed, 19 Jun 2024 13:23:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718803406; bh=ycFEkXDl6y1C0l2RytQLpK194U5NA3UpzsP2SnMdgTY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fuR9pA8TgkV6QKeH9vkmyg3X+RZR47rIxhm8AxCrnuQat+ONQcP9kDML4MiaSmH8f 98pBn4Kj6UXcSHpicqAEQXBdKOrLTWcjUNHvFBTtJ6OxThH0bHG2ATaLtHGm01qbsW dsCw/3hQowCLEQqyOZTXPZc5yREAJDDQ47OzZMko= 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 , Wachowski Subject: [PATCH 6.9 257/281] drm/shmem-helper: Fix BUG_ON() on mmap(PROT_WRITE, MAP_PRIVATE) Date: Wed, 19 Jun 2024 14:56:56 +0200 Message-ID: <20240619125619.869018718@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240619125609.836313103@linuxfoundation.org> References: <20240619125609.836313103@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 6.9-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 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 @@ -610,6 +610,9 @@ int drm_gem_shmem_mmap(struct drm_gem_sh return ret; } + if (is_cow_mapping(vma->vm_flags)) + return -EINVAL; + dma_resv_lock(shmem->base.resv, NULL); ret = drm_gem_shmem_get_pages(shmem); dma_resv_unlock(shmem->base.resv);