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 DFEAC332EBD; Wed, 20 May 2026 18:24:40 +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=1779301482; cv=none; b=ZBhNsK72tgoNQkHYSoP5L1G9GRqFTPdOpnfN4kvCSbspfN6F6iUH2vjkUwbQZh5TGTNVfys5hmQD1Du3R1FVesQxxftzkqYlS9lrOJ0lz4roaHX6jfP2ixr1nW9fB5vtCHYsYb/Olx0ZSZrjm6WS11blfx5wM/H+tUYYxUkUgmg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779301482; c=relaxed/simple; bh=o9MZlLx5Vrw3vczWMvRGEXvYBq4i7XJaiN+J/lK8WYE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=O3E5ulO4gTkP86UBJn/3NNeWOhnrcF8mnBxianxdw5fbRzHRGmDB/xYOvJgYc8XwQuBbS2P1UG2zo9lRWPD1uoUKm3e4YwITRMMHAki6xIQIbvfe+7qZmjzqdPPdY7szRBKtlHtRZF2yOdtimcSj0XZhGpANlpOrr1SInba20Ok= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Tmh871KB; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Tmh871KB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5186A1F000E9; Wed, 20 May 2026 18:24:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779301480; bh=nj3EXp0COAyq4GBnZWNuBlc0lQCp8V/NeRf5zwIRTC4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Tmh871KBKKihxZbQB7sylg+MZ9MshNGAhCn9rhoudEER0PyIgvFNOUQGoPggzjjti /H+zxM84XlAGzzXYxK/MeGBUPJETrUIvPeKh1AWRDGCw/33CYWRtOtzcvr4NABf1Ck GMr/AFMAqwYTxSY0sgkospQ88eAvKw67TO8qwRYM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Christian=20K=C3=B6nig?= , Alex Deucher , Sasha Levin Subject: [PATCH 6.12 519/666] drm/amdgpu: fix AMDGPU_INFO_READ_MMR_REG Date: Wed, 20 May 2026 18:22:10 +0200 Message-ID: <20260520162122.512581308@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162111.222830634@linuxfoundation.org> References: <20260520162111.222830634@linuxfoundation.org> User-Agent: quilt/0.69 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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christian König [ Upstream commit 0ef196a208385b7d7da79f411c161b04e97283e2 ] There were multiple issues in that code. First of all the order between the reset semaphore and the mm_lock was wrong (e.g. copy_to_user) was called while holding the lock. Then we allocated memory while holding the reset semaphore which is also a pretty big bug and can deadlock. Then we used down_read_trylock() instead of waiting for the reset to finish. Signed-off-by: Christian König Fixes: 9e823f307074 ("drm/amdgpu: Block MMR_READ IOCTL in reset") Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher (cherry picked from commit 361b6e6b303d4b691f6c5974d3eaab67ca6dd90e) Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c | 57 +++++++++++-------------- 1 file changed, 24 insertions(+), 33 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c index c626f66ded189..6788265157dbf 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c @@ -786,68 +786,59 @@ int amdgpu_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp) ? -EFAULT : 0; } case AMDGPU_INFO_READ_MMR_REG: { - int ret = 0; - unsigned int n, alloc_size; - uint32_t *regs; unsigned int se_num = (info->read_mmr_reg.instance >> AMDGPU_INFO_MMR_SE_INDEX_SHIFT) & AMDGPU_INFO_MMR_SE_INDEX_MASK; unsigned int sh_num = (info->read_mmr_reg.instance >> AMDGPU_INFO_MMR_SH_INDEX_SHIFT) & AMDGPU_INFO_MMR_SH_INDEX_MASK; - - if (!down_read_trylock(&adev->reset_domain->sem)) - return -ENOENT; + unsigned int alloc_size; + uint32_t *regs; + int ret; /* set full masks if the userspace set all bits * in the bitfields */ - if (se_num == AMDGPU_INFO_MMR_SE_INDEX_MASK) { + if (se_num == AMDGPU_INFO_MMR_SE_INDEX_MASK) se_num = 0xffffffff; - } else if (se_num >= AMDGPU_GFX_MAX_SE) { - ret = -EINVAL; - goto out; - } + else if (se_num >= AMDGPU_GFX_MAX_SE) + return -EINVAL; - if (sh_num == AMDGPU_INFO_MMR_SH_INDEX_MASK) { + if (sh_num == AMDGPU_INFO_MMR_SH_INDEX_MASK) sh_num = 0xffffffff; - } else if (sh_num >= AMDGPU_GFX_MAX_SH_PER_SE) { - ret = -EINVAL; - goto out; - } + else if (sh_num >= AMDGPU_GFX_MAX_SH_PER_SE) + return -EINVAL; - if (info->read_mmr_reg.count > 128) { - ret = -EINVAL; - goto out; - } + if (info->read_mmr_reg.count > 128) + return -EINVAL; - regs = kmalloc_array(info->read_mmr_reg.count, sizeof(*regs), GFP_KERNEL); - if (!regs) { - ret = -ENOMEM; - goto out; - } + regs = kmalloc_array(info->read_mmr_reg.count, sizeof(*regs), + GFP_KERNEL); + if (!regs) + return -ENOMEM; + down_read(&adev->reset_domain->sem); alloc_size = info->read_mmr_reg.count * sizeof(*regs); - amdgpu_gfx_off_ctrl(adev, false); + ret = 0; for (i = 0; i < info->read_mmr_reg.count; i++) { if (amdgpu_asic_read_register(adev, se_num, sh_num, info->read_mmr_reg.dword_offset + i, ®s[i])) { DRM_DEBUG_KMS("unallowed offset %#x\n", info->read_mmr_reg.dword_offset + i); - kfree(regs); - amdgpu_gfx_off_ctrl(adev, true); ret = -EFAULT; - goto out; + break; } } amdgpu_gfx_off_ctrl(adev, true); - n = copy_to_user(out, regs, min(size, alloc_size)); - kfree(regs); - ret = (n ? -EFAULT : 0); -out: up_read(&adev->reset_domain->sem); + + if (!ret) { + ret = copy_to_user(out, regs, min(size, alloc_size)) + ? -EFAULT : 0; + } + kfree(regs); return ret; } case AMDGPU_INFO_DEV_INFO: { -- 2.53.0