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 3131A346E68 for ; Wed, 27 May 2026 12:19:54 +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=1779884397; cv=none; b=fkp2rzKdr5eGKDtj9mSV8KYAwjIJ7g0FjoXIG7IMD+KrZJaOuHwq64n1NJoVaSASznkFhQ9vKmH+kbLofv/tVHdv8cKDPX2Yi8GnT2ROOyP90tGDts1sbEvqmA3R8RmqkEMwGacS+gL5Ci5bVm3Vb+pQI7oYTHh8t03DER8QE8w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779884397; c=relaxed/simple; bh=VkjbGPV8JVtWQJiZRSniHO4TOpDnEaftBeik7A7N+z4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=jKBCIcZtEK3oH2LfLfS3/TRsV6zfKwHoqvAC7nYGVNWoFPJcX0pSF81f8/rIgys5VYnuJaOmnhaQrwcCPUJbyZD2jR78r68rLAg1QdcELSe4tBJOlbCQjRQ6OAh9OqFm0D7OqmdH4Xx12447j7Mu/JbQOcDoPv6qoJtJsjjh4k8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=K4LRTg4G; 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="K4LRTg4G" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8DF0F1F000E9; Wed, 27 May 2026 12:19:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779884394; bh=/nPrE3nDyOFGjN2z+oK7UVqg0qJY8aiyshuBRMPpyMo=; h=From:To:Cc:Subject:Date:Reply-To; b=K4LRTg4GPiLvA5x9tvHCQ3jZu3puYDYQPeUE0ujIlbQEzBZzPFgZRMDZiHxalj6cn FWsd29MT2sUGd+2k8O3ZmbBokOFde93+lMQBQyhpqedL9flQNmEwYFnhEEqLqYZUV6 YmfEy3qJXIwKQbT9ZKcZxMupScF3yK2fxQCicJlU= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2025-71305: drm/display/dp_mst: Add protection against 0 vcpi Date: Wed, 27 May 2026 14:18:04 +0200 Message-ID: <2026052706-CVE-2025-71305-d814@gregkh> X-Mailer: git-send-email 2.54.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=5246; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=QaUvVGsAIwKXJEp55XzneYYcs1grQdB8hqcEeJhQfSs=; b=owGbwMvMwCRo6H6F97bub03G02pJDFliD/6dS5jcfNWck89/4vVfld8X3U7TflnS2q3pfHLr/ T+Gn2/VdsSyMAgyMciKKbJ82cZzdH/FIUUvQ9vTMHNYmUCGMHBxCsBElvIyLGhs+XmO12ZLR8gp b3/+W/pL2kM9NzEs2Hzcz1r7vTb3PX87TabN746m3XQNAQA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: drm/display/dp_mst: Add protection against 0 vcpi When releasing a timeslot there is a slight chance we may end up with the wrong payload mask due to overflow if the delayed_destroy_work ends up coming into play after a DP 2.1 monitor gets disconnected which causes vcpi to become 0 then we try to make the payload = ~BIT(vcpi - 1) which is a negative shift. VCPI id should never really be 0 hence skip changing the payload mask if VCPI is 0. Otherwise it leads to <7> [515.287237] xe 0000:03:00.0: [drm:drm_dp_mst_get_port_malloc [drm_display_helper]] port ffff888126ce9000 (3) <4> [515.287267] -----------[ cut here ]----------- <3> [515.287268] UBSAN: shift-out-of-bounds in ../drivers/gpu/drm/display/drm_dp_mst_topology.c:4575:36 <3> [515.287271] shift exponent -1 is negative <4> [515.287275] CPU: 7 UID: 0 PID: 3108 Comm: kworker/u64:33 Tainted: G S U 6.17.0-rc6-lgci-xe-xe-3795-3e79699fa1b216e92+ #1 PREEMPT(voluntary) <4> [515.287279] Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER <4> [515.287279] Hardware name: ASUS System Product Name/PRIME Z790-P WIFI, BIOS 1645 03/15/2024 <4> [515.287281] Workqueue: drm_dp_mst_wq drm_dp_delayed_destroy_work [drm_display_helper] <4> [515.287303] Call Trace: <4> [515.287304] <4> [515.287306] dump_stack_lvl+0xc1/0xf0 <4> [515.287313] dump_stack+0x10/0x20 <4> [515.287316] __ubsan_handle_shift_out_of_bounds+0x133/0x2e0 <4> [515.287324] ? drm_atomic_get_private_obj_state+0x186/0x1d0 <4> [515.287333] drm_dp_atomic_release_time_slots.cold+0x17/0x3d [drm_display_helper] <4> [515.287355] mst_connector_atomic_check+0x159/0x180 [xe] <4> [515.287546] drm_atomic_helper_check_modeset+0x4d9/0xfa0 <4> [515.287550] ? __ww_mutex_lock.constprop.0+0x6f/0x1a60 <4> [515.287562] intel_atomic_check+0x119/0x2b80 [xe] <4> [515.287740] ? find_held_lock+0x31/0x90 <4> [515.287747] ? lock_release+0xce/0x2a0 <4> [515.287754] drm_atomic_check_only+0x6a2/0xb40 <4> [515.287758] ? drm_atomic_add_affected_connectors+0x12b/0x140 <4> [515.287765] drm_atomic_commit+0x6e/0xf0 <4> [515.287766] ? _pfx__drm_printfn_info+0x10/0x10 <4> [515.287774] drm_client_modeset_commit_atomic+0x25c/0x2b0 <4> [515.287794] drm_client_modeset_commit_locked+0x60/0x1b0 <4> [515.287795] ? mutex_lock_nested+0x1b/0x30 <4> [515.287801] drm_client_modeset_commit+0x26/0x50 <4> [515.287804] __drm_fb_helper_restore_fbdev_mode_unlocked+0xdc/0x110 <4> [515.287810] drm_fb_helper_hotplug_event+0x120/0x140 <4> [515.287814] drm_fbdev_client_hotplug+0x28/0xd0 <4> [515.287819] drm_client_hotplug+0x6c/0xf0 <4> [515.287824] drm_client_dev_hotplug+0x9e/0xd0 <4> [515.287829] drm_kms_helper_hotplug_event+0x1a/0x30 <4> [515.287834] drm_dp_delayed_destroy_work+0x3df/0x410 [drm_display_helper] <4> [515.287861] process_one_work+0x22b/0x6f0 <4> [515.287874] worker_thread+0x1e8/0x3d0 <4> [515.287879] ? __pfx_worker_thread+0x10/0x10 <4> [515.287882] kthread+0x11c/0x250 <4> [515.287886] ? __pfx_kthread+0x10/0x10 <4> [515.287890] ret_from_fork+0x2d7/0x310 <4> [515.287894] ? __pfx_kthread+0x10/0x10 <4> [515.287897] ret_from_fork_asm+0x1a/0x30 The Linux kernel CVE team has assigned CVE-2025-71305 to this issue. Affected and fixed versions =========================== Fixed in 6.1.165 with commit 95dbd525efce2a9e9e1c50ad15213de644c85ad0 Fixed in 6.6.128 with commit ac9a7c329a5610051fc476644c9b9145a5965ecb Fixed in 6.12.75 with commit 3f44cdb5371faf225af37d5caba8f21ec0572469 Fixed in 6.18.16 with commit 4d2ccdea18b564e3f73e3e543854acea64e6277d Fixed in 6.19.4 with commit d6afc7539ce06dadfa5b4787b3cfe79b95d8f67a Fixed in 7.0 with commit 342ccffd9f77fc29fe1c05fd145e4d842bd2feaa Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2025-71305 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: drivers/gpu/drm/display/drm_dp_mst_topology.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/95dbd525efce2a9e9e1c50ad15213de644c85ad0 https://git.kernel.org/stable/c/ac9a7c329a5610051fc476644c9b9145a5965ecb https://git.kernel.org/stable/c/3f44cdb5371faf225af37d5caba8f21ec0572469 https://git.kernel.org/stable/c/4d2ccdea18b564e3f73e3e543854acea64e6277d https://git.kernel.org/stable/c/d6afc7539ce06dadfa5b4787b3cfe79b95d8f67a https://git.kernel.org/stable/c/342ccffd9f77fc29fe1c05fd145e4d842bd2feaa