From nobody Fri Oct 2 05:29:49 2026 Received: from mail-pf1-f177.google.com (mail-pf1-f177.google.com [209.85.210.177]) (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 38CF047D93A for ; Tue, 4 Aug 2026 21:37:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.177 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785879456; cv=none; b=OAiSi1rs/WyF8oJoLIW55mPcki2ffg+JA5//2Knn90WZnEbYRYqVJiFSkgVea0+pyjZszRxpO9HAXtfdEtMW7Th5QbHPFKd5tgsWaUJotqYQQEcQWKLFsyaL3Lb6xWoagYnwPJL6NNf6cvMU74LrSNbafXVBjPXiTdaQ8xqoEQc= 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=209.85.210.177 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-pf1-f177.google.com with SMTP id d2e1a72fcca58-8485ef63b68so413387b3a.1 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=CCK1jTiBHCeceRNEva8LMeQ943d8cxO+Ca/jyHmDO9Wa9eDSn0KQAjiWqPhao5aD8K aun2RrdFghDVxvBrjgsEiyZ86JFReHlmiiJiqEFW1bXn48udcek1MLPJE1wJbgYH3V7T 6h90UwXsQhz26l1DtnfGhA/j3auSDUSMTFG6uVOgfQmMjh+zhc/OhRzUc8ZnE9CSvo6M ctNcYmFWlYn0vlzdl1ydGwT0Oe7Y40u/W60qjwiH8VCLbS7WVSqcQnwurdSwRAfqYqJp uU/C6mDn8ycYH3Q0i8A1iZKxHU2+Zj6F0lAOliJ/W9yhlDx/fO+3h1ljNb8G0imJ/NFj zSnw== X-Forwarded-Encrypted: i=1; AHgh+Rp4qVCAh19mRC1WxPl4DJtDXwjC4M35Hqq2eetCkFZoyOoHo+hniYf+5EDHxNOX6flalEt1w5Kh0uC1iss=@vger.kernel.org X-Gm-Message-State: AOJu0YyNYaF5BXD9umHkUHT0irXeJvbed+kY3xTfypVHcCwudhV/b3FZ 2pkHc2JKHZJ8K5x7Bf8Q1GxfdzcdrW1AMwjYbLec7qitj08IZBrFPllG X-Gm-Gg: AR+sD13eQdNPusGb/pTb/dff2lHsJOwKqCRMpX4CCPs3gEpD/D9JYIjGg5XeYNEPLUd +zb0aa3Rc8SElYRvjBk5gH0qwaepdQXpkhXEGqez9tIGtyuwPEDv1l5jcTUNamLthS9naaR680x bGJhxtbqt9jcoZgjl1j6ShOljQl55dydN74CM/xbu+CKXr8cpxZST4uwA0ElpKsKJM0yYjg2WvC k/yNCJwG2Jp4e4mBQnTx0JQeh+k4OHNY5g6hjq7RQ++AmCad3ERz9GVKtEtzex3onXGP0dd/2j6 s5NnbO0r/3HgjSDzyAmao9WYp0Ml0Q7zICdnyHyW9dGghTP7AtxOXNpXZD44Ymf9Y5sBDuOBb4H GUgnBajOpF/dR52ESMElCDLLr4K8TO949/2j6S3M+/Dzq2cSDqiOrpuIG2cqv1stUqoRkcSNH58 039H632YZZvdVqeOrPdy+gt5f1/5XhHN168F1SWaHxxkhdvm2KNi8DQFTa6fMbiP1RPwc2viyUl sYrwcjhoDC3M8tlkJVVJCuXiqhZv9F8pUn52tE2myE= 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-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 hli= st") 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_co= re_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 !=3D rtpi) continue; =20 - kref_get(&deve->pr_kref); + if (!kref_get_unless_zero(&deve->pr_kref)) + continue; rcu_read_unlock(); =20 return deve; --=20 2.43.0