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 D9A75381AE4; Fri, 7 Aug 2026 15:03:58 +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=1786115043; cv=none; b=tDz2iMVzbKvl7quL35sxP0zzlOxxydjEHm9UiiI2fdljjUy3y93mMVZg2NhBBux5g4/R61Tu0r9EVwD7yKjolaccUp6yNkoInk6QCmXI/AzrHn9m48S1M8OBEU8BxkNa8A6I26Tb7CwbaK3Xf6BCB+cvLLvA5XxTvyyrSkONyAQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786115043; c=relaxed/simple; bh=uM3O1z7vn9flzdsfEKe4esY1O9tL6K+LIRQkvu9Ia0s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=H+I9XKXx843wT2s2ItrBhqwN0dL0n3dLSUGn5GpNEZ1zDp6mCMUlZ59ZzwKQvri9IulDfeoWf9kQr7eTehMhQRLDp/Tc5GFwhpGcQX3fTNpK8Q8WwyF8tb8OFEpVxzx09i4iKyw+PkcWtTL7xP1VfaoJuKPxTpUj2oiDU9GdtrE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sNvRD15k; 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="sNvRD15k" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3179D1F000E9; Fri, 7 Aug 2026 15:03:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786115036; bh=t2IfnWqXxWs0Fxj1sNyMikMPiyO1ARWPSDu+KO3iXuc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=sNvRD15kYCncxcFxUowFQAJBGk6Sqx2BsffuS68MSCASojc/yvGpF25ugUUOyx4Bt fdnQ75mcBpuC/3Gv1bOKz33LZFy57+cUTUZj/8ekB5CDZcct99txFGmVONtHQxDn8+ rqEb44VYfJ4m59dRQ4Q9H2PUW+MPBxuJH1PXD6j8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Leon Romanovsky , Mike Christie , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 6.18 133/396] scsi: target: Clear cmd_cnt when initial counter enrollment fails Date: Fri, 7 Aug 2026 16:34:53 +0200 Message-ID: <20260807143427.173391631@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260807143424.272339768@linuxfoundation.org> References: <20260807143424.272339768@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev 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: Leon Romanovsky [ Upstream commit a8ddfd2425bbbafadae8700d63ed8a61a4109878 ] When target_get_sess_cmd() fails during session shutdown because percpu_ref_tryget_live() returns false, the command keeps the se_cmd->cmd_cnt pointer that __target_init_cmd() assigned earlier without owning a reference. Final release through target_release_cmd_kref() then issues an unmatched percpu_ref_put(). Commit 8e288be8606a ("scsi: target: Pass in cmd counter to use during cmd setup") moved the cmd_cnt assignment ahead of the reference acquisition. Clear se_cmd->cmd_cnt whenever the initial target_get_sess_cmd() fails in target_init_cmd() and target_submit_tmr(), so release performs exactly one matching put per acquired reference. Fixes: 8e288be8606a ("scsi: target: Pass in cmd counter to use during cmd setup") Signed-off-by: Leon Romanovsky Reviewed-by: Mike Christie Link: https://patch.msgid.link/20260722-reference-count-underflow-in-target-v1-1-63ab664f12fd@nvidia.com Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/target/target_core_transport.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 88544c911949c..5ad2dcf730cd2 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -1691,6 +1691,7 @@ int target_init_cmd(struct se_cmd *se_cmd, struct se_session *se_sess, u32 data_length, int task_attr, int data_dir, int flags) { struct se_portal_group *se_tpg; + int ret; se_tpg = se_sess->se_tpg; BUG_ON(!se_tpg); @@ -1720,7 +1721,11 @@ int target_init_cmd(struct se_cmd *se_cmd, struct se_session *se_sess, * necessary for fabrics using TARGET_SCF_ACK_KREF that expect a second * kref_put() to happen during fabric packet acknowledgement. */ - return target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF); + ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF); + if (ret) + se_cmd->cmd_cnt = NULL; + + return ret; } EXPORT_SYMBOL_GPL(target_init_cmd); @@ -1996,8 +2001,10 @@ int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess, * allocation failure. */ ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp); - if (ret < 0) + if (ret < 0) { + se_cmd->cmd_cnt = NULL; return -ENOMEM; + } if (tm_type == TMR_ABORT_TASK) se_cmd->se_tmr_req->ref_task_tag = tag; @@ -2005,6 +2012,7 @@ int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess, /* See target_submit_cmd for commentary */ ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF); if (ret) { + se_cmd->cmd_cnt = NULL; core_tmr_release_req(se_cmd->se_tmr_req); return ret; } -- 2.53.0