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 323313A7F48 for ; Sun, 19 Jul 2026 15:43:49 +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=1784475830; cv=none; b=FlMAnyq4YeBUajC2DHuHwNdCjv51oFeh0nn5wmKISot14UYIkDXSU8FdHt2e9N0HcAyZP7SI2kwpbtLm+6n2i9O2VXx/vxAcutdHeKAswg+cqyjx1T8NO61Ouv4T/MGB1TVkpL6W0r5Cbh5Mam0azJXhiOQABLyFmPrve7KjDIU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784475830; c=relaxed/simple; bh=0Q133T7h570Hqx0Ufy2zosHjwA/W3Eglsl6YRe5N/Ng=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=nwkeD0jgOeIeC7YjAUNe7LabGN5SWI50Dj61begwTeWeJ+LJe047dvShg3zhSwRE4+In1HiKV7m5LHI4TYuv72Ck2gNe4UZvo1jZYzxSv9Ekr9MpvOC1paYKeVK2Hj4AcAoXp4BKB6y2xiwv2rFe2jDXnE187QZNFuVbWObyXlA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=PEt3y/GC; 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="PEt3y/GC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 94EE91F000E9; Sun, 19 Jul 2026 15:43:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784475829; bh=5deSoBwFMaqXzIm+dSk2o98ecMg/AAU8diJHvZ4Se+w=; h=From:To:Cc:Subject:Date:Reply-To; b=PEt3y/GCQbJpPinlczdFD1HuWx1xKiPQXtEmhihBeRbV8BlZu59cbuvhstOcJOm6k UqYjL1IAdIR4zm2MPs4c+9KGfW6YuvSSbRvHo4+kDifDwb0X8YKc+ZMUxFk8lSSmp9 T7dyK44FdyFofFh6/5NkrSlVeHAAdghjAOUUUxEk= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-64100: drm/msm: Fix shrinker deadlock Date: Sun, 19 Jul 2026 17:39:22 +0200 Message-ID: <2026071919-CVE-2026-64100-39f2@gregkh> X-Mailer: git-send-email 2.55.0 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=5977; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=OJNkJpABLP5kWKnDMbxjbXSUgQSK7djT+DI40IK0Afc=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkx73Nyk5MnnD93+/ZeDd8HVr03ZHPUf6qkMhgvORrqZ 9Z7bIJ+RywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAExE4QDDgpUVdwP3nWp/oqok 5qhy5uTbx6uO2jDMT8/duEGx3fHtdda9TGGHs9WnKztKAwA= 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/msm: Fix shrinker deadlock With PROVE_LOCKING on an Snapdragon X1 and VM reclaim pressure, we see: ====================================================== WARNING: possible circular locking dependency detected 7.0.0-debug+ #43 Tainted: G W ------------------------------------------------------ kswapd0/82 is trying to acquire lock: ffff800080ec3870 (reservation_ww_class_acquire){+.+.}-{0:0}, at: msm_gem_shrinker_scan+0x17c/0x400 [msm] but task is already holding lock: ffffc31709b263b8 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x88/0x988 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (fs_reclaim){+.+.}-{0:0}: __lock_acquire+0x4d0/0xad0 lock_acquire.part.0+0xc4/0x248 lock_acquire+0x8c/0x248 fs_reclaim_acquire+0xd0/0xf0 dma_resv_lockdep+0x224/0x348 do_one_initcall+0x84/0x5d0 do_initcalls+0x194/0x1d8 kernel_init_freeable+0x128/0x180 kernel_init+0x2c/0x160 ret_from_fork+0x10/0x20 -> #1 (reservation_ww_class_mutex){+.+.}-{4:4}: __lock_acquire+0x4d0/0xad0 lock_acquire.part.0+0xc4/0x248 lock_acquire+0x8c/0x248 dma_resv_lockdep+0x1a8/0x348 do_one_initcall+0x84/0x5d0 do_initcalls+0x194/0x1d8 kernel_init_freeable+0x128/0x180 kernel_init+0x2c/0x160 ret_from_fork+0x10/0x20 -> #0 (reservation_ww_class_acquire){+.+.}-{0:0}: check_prev_add+0x114/0x790 validate_chain+0x594/0x6f0 __lock_acquire+0x4d0/0xad0 lock_acquire.part.0+0xc4/0x248 lock_acquire+0x8c/0x248 drm_gem_lru_scan+0x1ac/0x440 msm_gem_shrinker_scan+0x17c/0x400 [msm] do_shrink_slab+0x150/0x4a0 shrink_slab+0x144/0x460 shrink_one+0x9c/0x1b0 shrink_many+0x27c/0x5c0 shrink_node+0x344/0x550 balance_pgdat+0x2c0/0x988 kswapd+0x11c/0x318 kthread+0x10c/0x128 ret_from_fork+0x10/0x20 other info that might help us debug this: Chain exists of: reservation_ww_class_acquire --> reservation_ww_class_mutex --> fs_reclaim Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(reservation_ww_class_mutex); lock(fs_reclaim); lock(reservation_ww_class_acquire); *** DEADLOCK *** 1 lock held by kswapd0/82: #0: ffffc31709b263b8 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x88/0x988 stack backtrace: CPU: 4 UID: 0 PID: 82 Comm: kswapd0 Tainted: G W 7.0.0-debug+ #43 PREEMPT(full) Tainted: [W]=WARN Hardware name: LENOVO 21BX0016US/21BX0016US, BIOS N3HET94W (1.66 ) 09/15/2025 Call trace: show_stack+0x20/0x40 (C) dump_stack_lvl+0x9c/0xd0 dump_stack+0x18/0x30 print_circular_bug+0x114/0x120 check_noncircular+0x178/0x198 check_prev_add+0x114/0x790 validate_chain+0x594/0x6f0 __lock_acquire+0x4d0/0xad0 lock_acquire.part.0+0xc4/0x248 lock_acquire+0x8c/0x248 drm_gem_lru_scan+0x1ac/0x440 msm_gem_shrinker_scan+0x17c/0x400 [msm] do_shrink_slab+0x150/0x4a0 shrink_slab+0x144/0x460 shrink_one+0x9c/0x1b0 shrink_many+0x27c/0x5c0 shrink_node+0x344/0x550 balance_pgdat+0x2c0/0x988 kswapd+0x11c/0x318 kthread+0x10c/0x128 ret_from_fork+0x10/0x20 kswapd0 holding fs_reclaim calls the MSM shrinker, which calls dma_resv_lock. This in turn acquires fs_reclaim. Fix this deadlock by using dma_resv_trylock() instead, dropping the subsequently unused passed wait-wound lock 'ticket'. Patchwork: https://patchwork.freedesktop.org/patch/723564/ [rob: fixup compile errors, replace lockdep splat with something legible] The Linux kernel CVE team has assigned CVE-2026-64100 to this issue. Affected and fixed versions =========================== Issue introduced in 6.17 with commit fe4952b5f27cca5d143d3de249562d4cc984c1d6 and fixed in 6.18.34 with commit 942968260e61d4a5d7552b20814b6277f9c553df Issue introduced in 6.17 with commit fe4952b5f27cca5d143d3de249562d4cc984c1d6 and fixed in 7.0.11 with commit 928788566c79046f71a211fc32c115400be76402 Issue introduced in 6.17 with commit fe4952b5f27cca5d143d3de249562d4cc984c1d6 and fixed in 7.1 with commit 3392291fc509d8ad6e4ad90f15b0a193f721cbc9 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-2026-64100 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/msm/msm_gem_shrinker.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/942968260e61d4a5d7552b20814b6277f9c553df https://git.kernel.org/stable/c/928788566c79046f71a211fc32c115400be76402 https://git.kernel.org/stable/c/3392291fc509d8ad6e4ad90f15b0a193f721cbc9