From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794410523; b=GMgtNq5ZunA9SWEG/HtIbA/Elk3CwfYjQ3MAVWbHC08kZQuO/pklU85VH2E2bLh5wd54 io0UUOXaQuQ6Cb+UTlwn6IJBtUWJutLQWCDyzpzLXDbdXrMQMbXthXcqSWHWqWZFaIFgE chZw6SsqWJQTAIORsNfm+AyiEEVGiyERfRkYad40Jy4p6TgQNTZZK0TVWSDDCejEMXcgG zsbh9UJBNmPaVG4Ot48XVAvJWmSlsGVDvQ/RPJGNQNUxpyQTxJp0evH+oTT0jGkeZYAAe nW877aqCPRs5OA2To5cmS2is+pzV9R5y1RzqZd9YIFBTp93AVtKsMpye1/PUGELmmKA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794410523; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=83AijDFiKvka1U60CUSjmnP36j06f9/2sqU+mmrsOaM=; b=AWqwdAXoC61DgypTKKYI+N8gOsxt9f6EoVEf2EiZMzr3mhEAMvDrRgF6351yoMnSQMcn GFVaeqRe+3uqo4oNFqE9agynE6rMFP0JVX9WyrecoMEGzwpLP3Y8goc+FPM7Wjmwzkbgt /5P2q0GWjXwb65pu9tv7HxLxvqLT9QR7sa/TIjMhFrrcMwHhDz2/NICq4UN0E6lcVzKiK 8Vqsop59rmo71ngwjR/zViL5zJpEM8xUQaNuVzzrgaHU9tOI+ar5lcwz3mlDosA71xYTU kS7xWpdrgzYIo9/bobbY122EnKi03v4lvgSVYl044rwpQsZ5cYfoHrewkahDiE7dDQQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ksaT6vmT; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 18B97606A339 for ; Wed, 11 Nov 2026 15:22:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ksaT6vmT Received: by smtp.kernel.org (Postfix) with ESMTPSA id 120161F00A07; Wed, 11 Nov 2026 15:22:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794410522; bh=83AijDFiKvka1U60CUSjmnP36j06f9/2sqU+mmrsOaM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ksaT6vmTiHGGP8CpBQy37P5fqp0BWtMSA221Mx9bAxJyqiAL9N6hXTnVVrlYBw5SH g1jzpSbBvOCXMzrFMcPmRVbD/96VBt1jpA/xU1a/7iDN9NK08fPPa/MmkKLHwAyJhz yBd2vCNnFjfWZZaNmqr642C8pMxbXplVT+m7ptoTfD0rmWyGMXZt7aNzPPxBdCA/b7 iyuoFwVHgu+9SHE6Kh5tMDTsRCB0b09ExHpPT55DMGCSB+dAIfiMZKvFEFUUcXWPU8 Sx/3SzDT/Z235/rMVnzfo/buA0uYR2gAMfpFbc+swX1AESf1YHJQJsNsV8X4FL19Ad 77mDGT1UxAt3A== From: Sasha Levin To: stable@vger.kernel.org Cc: Jesse Zhang , =?UTF-8?q?Christian=20K=C3=B6nig?= , Arunpravin Paneer Selvam , Sasha Levin Subject: [PATCH 5.15.y] drm/ttm: return an error when kmapping a BO without pages Date: Wed, 11 Nov 2026 10:22:00 -0500 Message-ID: <20261111152139.2597907-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261107060349-failed-5.15-fd485d47437b@kernel.org> References: <20261107060349-failed-5.15-fd485d47437b@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Jesse Zhang [ Upstream commit fd485d47437ba1700dd47205a63b9f389a00aa36 ] ttm_tt objects for imported sg tables (ttm_bo_type_sg, set up by ttm_sg_tt_init() with TTM_TT_FLAG_EXTERNAL) only have DMA addresses and no pages array. ttm_bo_kmap() and ttm_bo_vmap() still dereference ttm->pages for them, so a driver that tries to CPU map such a BO oopses instead of getting an error: BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:ttm_bo_kmap+0x26c/0x300 [ttm] Call Trace: amdgpu_bo_kmap+0x89/0xb0 [amdgpu] amdgpu_userq_fence_read_wptr+0x116/0x170 [amdgpu] amdgpu_userq_signal_ioctl+0x3fe/0xbb0 [amdgpu] Return -EINVAL in that case, like ttm_bo_kmap_try_from_panic() already checks for a missing pages array. Fixes: 75a57669cbc8 ("drm/ttm: add ttm_sg_tt_init") Cc: stable@vger.kernel.org Suggested-by: Christian König Reviewed-by: Christian König Signed-off-by: Jesse Zhang Signed-off-by: Arunpravin Paneer Selvam Link: https://patch.msgid.link/20261009103419.4122940-1-Jesse.Zhang@amd.com [ sashal: Moved the API documentation updates to the existing header declarations. ] Signed-off-by: Sasha Levin --- drivers/gpu/drm/ttm/ttm_bo_util.c | 7 +++++++ include/drm/ttm/ttm_bo_api.h | 4 ++-- 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c index abf2d7a4fdf1a..1c582e4824e6a 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_util.c +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c @@ -312,6 +312,10 @@ static int ttm_bo_kmap_ttm(struct ttm_buffer_object *bo, if (ret) return ret; + /* Imported sg tables only come with DMA addresses, no pages to map. */ + if (!ttm->pages) + return -EINVAL; + if (num_pages == 1 && ttm->caching == ttm_cached) { /* * We're mapping a single page, and the desired @@ -429,6 +433,9 @@ int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map) if (ret) return ret; + if (!ttm->pages) + return -EINVAL; + /* * We need to use vmap to get the desired page protection * or to make the buffer object look contiguous. diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 36f7eb9d06639..ada4d625bf8f7 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -474,7 +474,7 @@ static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map, * * Returns * -ENOMEM: Out of memory. - * -EINVAL: Invalid range. + * -EINVAL: Invalid range or the BO has no pages to map. */ int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page, unsigned long num_pages, struct ttm_bo_kmap_obj *map); @@ -500,7 +500,7 @@ void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map); * * Returns * -ENOMEM: Out of memory. - * -EINVAL: Invalid range. + * -EINVAL: Invalid range or the BO has no pages to map. */ int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map); -- 2.53.0