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 76B06233933; Wed, 20 May 2026 17:49:42 +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=1779299383; cv=none; b=pRNZOUQYajxfhCrl7rEKDFwCyPVoeOh+IFJz4eNFW17ZUCGfXNuh0+1h8iakkmxZuGRujBsUMYnyfwqpFkhWJNKXJ6NUpS2yPY9vB8/23wsZiPr2HST2ghfCcAEfXDc7PBukavYIW8F36XEHwEVTHk4IRH3SGyeXPID6R5Bc2xk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299383; c=relaxed/simple; bh=+IC8sq1wEGU/h7kY3cWV7MHqeOXxmdWBJw7gVEwm5yk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=j++li6CNEg3HTqVA0Z/QTA1RNDzdR97KZf/bWc3S+OJrPtjVJoggdtPxEWAxzOcFIq6k5Q3hc8AZ9eoYWExBTnVPSL1LT8ydvBqxzD1b0YUuZy1hh3vBrFxUkrv+U5YZbNGc0IS8ISZXuZGUjkLwhR7wP5V6k/8XcPMGTm7qNCA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tsdRsji+; 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="tsdRsji+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9BE6D1F000E9; Wed, 20 May 2026 17:49:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779299382; bh=BMih6XdJT4lWDKIYUCKcQxu3HMWNjhFQBIxnbXzc0VQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=tsdRsji+x1CTlElEcuWi9InsaPJ2jxrsKQXg1im21Sty4pUzfMtaLmry2iQj0zMVI 9pHMnzCs0pXjPBMSxTytyIVdjqhQ33W2KhnA5Bo01ei6oyIAidn5+A1YBTWuORn5CK oRZ8SgLSo4M4mICF+ta/VXkw+gqRlBNDuj995kbs= 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 6.18 749/957] drm/amdgpu: fix AMDGPU_INFO_READ_MMR_REG Date: Wed, 20 May 2026 18:20:32 +0200 Message-ID: <20260520162150.806491099@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162134.554764788@linuxfoundation.org> References: <20260520162134.554764788@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.18-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 d8c0154c5297d..915406ab9730d 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c @@ -837,68 +837,59 @@ 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