From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f177.google.com (mail-pg1-f177.google.com [209.85.215.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 38D9D480965 for ; Tue, 4 Aug 2026 21:37:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785879456; cv=none; b=S5fYUoYr/tiORwwotN2EQz5zb0cm5w3EfsRztWaklvMm2T2j7Yj0R+XyqE38YXHXV+SZp+521Cpnd9i1XgoT4zVpJFupeAqhn6xYD6aqpO9judwb60sbmbpyGE9eY8eOra9c453Gy+BhtcjiEOw+U2D5I5TInTd4XzwOwx7h0Kw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785879456; c=relaxed/simple; bh=hK4xPGY2IK3gul7IpcA8bnueNq7919WPVp+ViX9mklk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=lrhSkduu1Mf493JurmihYKlXfzw3ukG6YTdlf5KxANV/iHklLVjLRC2fdB4lSQb1X1fCVfjaqqjo5DZmiGB9OeSKjWTPuRmRT+cOscXWAblD0a+Czm3UX6ocl3IyoJqhiD7KrIxEtx3OXZ1MnQ1KfEXH0psy6xd0NeuXkWYA0ts= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=FP//a1VQ; arc=none smtp.client-ip=209.85.215.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="FP//a1VQ" Received: by mail-pg1-f177.google.com with SMTP id 41be03b00d2f7-c981c2c37cbso192222a12.0 for ; Tue, 04 Aug 2026 14:37:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1785879454; x=1786484254; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=JOJcT04MAKZ1R+76HgJ67upFnuCPH8VuW68e8b3zSd4=; b=FP//a1VQLkR01akOee+BfgGu0DLtvpJ5nNcfey3y5ZbeaaSQmH/RcmX75DbfFPVLLD MxxtgvvP/p3HaiO5uMRQjjyhYR03yEiiTL0usmgEINsjoXZRd5RQFFuXQaHgL6tLh4wr Teg2XwXLvw3G0QWREJX+g7Zbubbquuf8uXkgYC5EiG1zmuV/k5oZBIELlD8aA1/AUId+ oXfG59JQAWxIcwosJ64/n9Vso7VU+C6t5o7C2Heg/RvwO3WdqYVtzIdAHF41DkJiiK+I Dj+CPgXbzxo1P44btva8E6+01oDoG2LtpQxTUNESUnJJ5TTfFvjiWJZORGW7Tt9N3ewE /SwQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785879454; x=1786484254; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=JOJcT04MAKZ1R+76HgJ67upFnuCPH8VuW68e8b3zSd4=; b=gcqYHxkBhhT2gn8H9BmjheDwEOPDZA75vlLlmEMIUnGqTZu260qw/ADzTQv4H9wno+ SdSd5HzLP+GQmAEYzDp2dTnND89cvtNM7qHNpbgbEq3o/wOiCV0ezYwNo2G0qqZKYPrY c9P+B6Foq/rm/Wsi//w9JGsw6nTFEuv0Dphvx0ldzir2Xe8bI6nHCPZm5Vw0yUGxvlIE 6yXDUJQrkYAWOqmy+S3L+NhBWqXRDyvTpTvPTBPIG9dO+M5lqPQVBHhpM1cMjieliazP CJqzBPcDOm2ewFkQaVSvPhnc8hXcuxJduAtSmP2za0+9RemtbZXlJAYKO4y82nSGrr9y z2QQ== X-Forwarded-Encrypted: i=1; AHgh+RrzuQvbNOzADcAVxLA1UTXvMQwMpx22pWF60W5VYt4eAlv0fOBHv6FyNorXs7OfxxVNFDRfty9yTU9C@vger.kernel.org X-Gm-Message-State: AOJu0Yx33yexgt5f/LehHYN+h178TOY/5er4byUilwiyJY/MjYFk71pM lesj7m2N8yx1yiE2R48FqvHP4LhB3XJjmQONTaTvzDihw3sXkTzRlgq6qvJDPmy2 X-Gm-Gg: AR+sD11PuM6KwJe2haVIlpjMXQ0wD0BnYLu7CZRrrYDS6CgzGp76y/Mq3n8npslfdso 9wQR164EOSUraE2JzqK1QAU0V4SYPIVXvLimtKr7TdqnJs68v34ltWNkecSHxngdKb2zxapsl5M OFwsaUVBysts6EM8gvj5lp8oCpDouFz6yTMbMsJ2CnK6vZ3rLohsPi54cbRVrDYYdaRooWsxhy/ VZWyC8eNLy7Pu524qrRGmIbva5axZ95rQzHEtjiBg+xQEEVvOvQZEhYVLDFZnDu9Mq+xaxlN7Ey ccvTs+56joPHsmriw5bj1sy5qdv/7+q2yfiPMwwdh/uDctnC9OYCTijVxavE0h0IMMmKaIL1Jht 75QOWcnOLWjzpW2ZlQZw+cGXnAc0QDU2HUt5NuTSUEXnV14YJGvZrYfSMEEeyOC07olp/l3xhTH H3nhgmKTSPLdTzN95QAaKFANhV6W3ndKSaKk5IbGfIsonsSMSfl8mtjlglxdz3U/lP+TiS04CL+ hTF58PAbedyr2TRJ+2gOEJAQngNXBsMtkDTYdXnTJc= X-Received: by 2002:a05:6a21:3392:b0:3c3:9595:57ef with SMTP id adf61e73a8af0-3cb85ffd1cemr1992015637.31.1785879454517; Tue, 04 Aug 2026 14:37:34 -0700 (PDT) Received: from LAPTOP-DPAKMOI4.it.purdue.edu (pal-210-106-74.itap.purdue.edu. [128.210.106.74]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-3158673a9e4sm9532563eec.18.2026.08.04.14.37.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 04 Aug 2026 14:37:34 -0700 (PDT) From: Yifei Gao To: "Martin K . Petersen" , linux-scsi@vger.kernel.org, target-devel@vger.kernel.org Cc: Nicholas Bellinger , Hannes Reinecke , Mike Christie , linux-kernel@vger.kernel.org, Yifei Gao , stable@vger.kernel.org Subject: [PATCH] scsi: target: use kref_get_unless_zero() in core_get_se_deve_from_rtpi() Date: Tue, 4 Aug 2026 21:37:25 +0000 Message-ID: <20260804213726.3411698-1-gyf161023@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit core_get_se_deve_from_rtpi() iterates nacl->lun_entry_hlist under rcu_read_lock() and takes a plain kref_get() on deve->pr_kref for the matching entry. The disable path, core_disable_device_list_for_node(), unhashes the entry, drops the final reference, waits for pr_comp and frees it via call_rcu() while holding lun_entry_mutex, which the reader does not hold. A reader racing that path can revive the kref after it has reached zero, defeating the pr_comp completion barrier and leading to a use-after-free. Use kref_get_unless_zero() and skip entries whose refcount has already dropped to zero. Fixes: 29a05deebf6c ("target: Convert se_node_acl->device_list[] to RCU hlist") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Yifei Gao --- drivers/target/target_core_device.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index 9db2201aa553..bff97c6efffb 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -220,7 +220,8 @@ struct se_dev_entry *core_get_se_deve_from_rtpi( if (lun->lun_tpg->tpg_rtpi != rtpi) continue; - kref_get(&deve->pr_kref); + if (!kref_get_unless_zero(&deve->pr_kref)) + continue; rcu_read_unlock(); return deve; -- 2.43.0