From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1D47A274FE3 for ; Tue, 15 Jul 2025 08:14:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752567281; cv=none; b=i51NBxlvkG+aNrW2NdLDN38A6j4olh469QycvmenKXzInGhBD+ucp3WAmlPd1Vm4+xhJq8e2qv7bDnedRLJo4kXfadOn+3e1rm3I3IglvehOVISQcJUrefXcldXktBb6Jff2cQ1Fo0P5cloc6MGpmtNVNsvpKYvCx6doF+kmE/A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752567281; c=relaxed/simple; bh=7OKVidT+GhuEpNuBiWPfdUliLEqGrQvjJk+X0y2eNQo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=s9+2ZkH9ntWzIiKRW3A6TR+s3VevdtnkYzKfo1lBy9o2Bc3xPReJlIib7W50zTkVKoRRucgw9Eu5lLmRnGUjgqLqCSfO7NOMivzHGAGthABD3QbZK9kCPu+i0Pi/rAYRcwdm7MkjTlu8kUXvwb2Dutm9UFwT+Qn6DzpXk6sIG1o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; arc=none smtp.client-ip=195.135.223.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id EB2A01F44F; Tue, 15 Jul 2025 08:14:32 +0000 (UTC) Authentication-Results: smtp-out2.suse.de; none Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 6636A13A6C; Tue, 15 Jul 2025 08:14:32 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id kMbIF+gNdmgJUAAAD6G6ig (envelope-from ); Tue, 15 Jul 2025 08:14:32 +0000 From: Thomas Zimmermann To: simona@ffwll.ch, airlied@gmail.com, christian.koenig@amd.com, torvalds@linux-foundation.org, maarten.lankhorst@linux.intel.com, mripard@kernel.org, l.stach@pengutronix.de, linux+etnaviv@armlinux.org.uk, kraxel@redhat.com, christian.gmeiner@gmail.com, dmitry.osipenko@collabora.com, gurchetansingh@chromium.org, olvaffe@gmail.com, zack.rusin@broadcom.com Cc: bcm-kernel-feedback-list@broadcom.com, dri-devel@lists.freedesktop.org, etnaviv@lists.freedesktop.org, virtualization@lists.linux.dev, intel-gfx@lists.freedesktop.org, Thomas Zimmermann , Simona Vetter Subject: [PATCH v2 3/7] Revert "drm/etnaviv: Use dma_buf from GEM object instance" Date: Tue, 15 Jul 2025 10:07:54 +0200 Message-ID: <20250715081121.34473-4-tzimmermann@suse.de> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250715081121.34473-1-tzimmermann@suse.de> References: <20250715081121.34473-1-tzimmermann@suse.de> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spam-Level: X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[]; TAGGED_RCPT(0.00)[etnaviv] X-Rspamd-Queue-Id: EB2A01F44F X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Action: no action X-Spam-Flag: NO X-Spam-Score: -4.00 This reverts commit e91eb3ae415472b28211d7fed07fa283845b311e. The dma_buf field in struct drm_gem_object is not stable over the object instance's lifetime. The field becomes NULL when user space releases the final GEM handle on the buffer object. This resulted in a NULL-pointer deref. Workarounds in commit 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers") and commit f6bfc9afc751 ("drm/framebuffer: Acquire internal references on GEM handles") only solved the problem partially. They especially don't work for buffer objects without a DRM framebuffer associated. Hence, this revert to going back to using .import_attach->dmabuf. Signed-off-by: Thomas Zimmermann Reviewed-by: Simona Vetter --- drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c index 917ad527c961..40a50c60dfff 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c @@ -65,7 +65,7 @@ static void etnaviv_gem_prime_release(struct etnaviv_gem_object *etnaviv_obj) struct iosys_map map = IOSYS_MAP_INIT_VADDR(etnaviv_obj->vaddr); if (etnaviv_obj->vaddr) - dma_buf_vunmap_unlocked(etnaviv_obj->base.dma_buf, &map); + dma_buf_vunmap_unlocked(etnaviv_obj->base.import_attach->dmabuf, &map); /* Don't drop the pages for imported dmabuf, as they are not * ours, just free the array we allocated: @@ -82,7 +82,7 @@ static void *etnaviv_gem_prime_vmap_impl(struct etnaviv_gem_object *etnaviv_obj) lockdep_assert_held(&etnaviv_obj->lock); - ret = dma_buf_vmap(etnaviv_obj->base.dma_buf, &map); + ret = dma_buf_vmap(etnaviv_obj->base.import_attach->dmabuf, &map); if (ret) return NULL; return map.vaddr; -- 2.50.0