From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 C0C2123B604; Mon, 9 Feb 2026 14:30:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770647436; cv=none; b=r4XvR100k1qTdJYfumELkewImwNQ+g6bUiIlUpNk7tgeyrQzXn/oncQwFkRI0f3b42c2/wsIvjy/0QUKwiJ18lMpD5i7xVAATdtaMXk8T/7wUqN7T1U3QIWfRonImbUJ54ZRciUwEMIzA2JhoWvFPCL563Z10CYjDE5l8LV3vNA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770647436; c=relaxed/simple; bh=z+dfw7qW3j4PP0sbWhWt2eHFJxNL+WrEdi/s/PmqW+U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pr/6MWXLn60C66JKSbZNYDfQjw8+Uf7jynediSBcdy7XIrikXlPRto/Y2WmAMfLfdO33zHabcBrpwKdRUeBumaH710RKM6fe/IhnPLFU+6cM2pzuEKClyuwbnC3NJX8g5v5dfWO79WbanjGTJOJK0eaPM36Grtx+dxHePMwqBh8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LTNIEjp3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="LTNIEjp3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20E38C116C6; Mon, 9 Feb 2026 14:30:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1770647436; bh=z+dfw7qW3j4PP0sbWhWt2eHFJxNL+WrEdi/s/PmqW+U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LTNIEjp3EwhnQT7gUvWNZMnt7vDNgQVDcRHC2qcQOsjjn28OT1jd8NYh4rbDSoQXs MMkzDFuef2GUcb9UatJ1pdQYWsONwiOVPABkn9JTGChNwEIuu1nGb3TEz+QY5P8GPL 6hxV40jpcuzNwRcl6X9qvj6INWrpPLMBrrltvj8Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Maurizio Lombardi , Zhaojuan Guo , Mike Christie , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 6.18 100/175] scsi: target: iscsi: Fix use-after-free in iscsit_dec_session_usage_count() Date: Mon, 9 Feb 2026 15:22:53 +0100 Message-ID: <20260209142324.018595544@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260209142320.474120190@linuxfoundation.org> References: <20260209142320.474120190@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maurizio Lombardi [ Upstream commit 84dc6037390b8607c5551047d3970336cb51ba9a ] In iscsit_dec_session_usage_count(), the function calls complete() while holding the sess->session_usage_lock. Similar to the connection usage count logic, the waiter signaled by complete() (e.g., in the session release path) may wake up and free the iscsit_session structure immediately. This creates a race condition where the current thread may attempt to execute spin_unlock_bh() on a session structure that has already been deallocated, resulting in a KASAN slab-use-after-free. To resolve this, release the session_usage_lock before calling complete() to ensure all dereferences of the sess pointer are finished before the waiter is allowed to proceed with deallocation. Signed-off-by: Maurizio Lombardi Reported-by: Zhaojuan Guo Reviewed-by: Mike Christie Link: https://patch.msgid.link/20260112165352.138606-3-mlombard@redhat.com Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/target/iscsi/iscsi_target_util.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c index 5e6cf34929b55..262a3e76b4b1c 100644 --- a/drivers/target/iscsi/iscsi_target_util.c +++ b/drivers/target/iscsi/iscsi_target_util.c @@ -741,8 +741,11 @@ void iscsit_dec_session_usage_count(struct iscsit_session *sess) spin_lock_bh(&sess->session_usage_lock); sess->session_usage_count--; - if (!sess->session_usage_count && sess->session_waiting_on_uc) + if (!sess->session_usage_count && sess->session_waiting_on_uc) { + spin_unlock_bh(&sess->session_usage_lock); complete(&sess->session_waiting_on_uc_comp); + return; + } spin_unlock_bh(&sess->session_usage_lock); } -- 2.51.0