From patchwork Tue Jun 28 17:56:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 12898623 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79B6CC433EF for ; Tue, 28 Jun 2022 17:56:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232313AbiF1R4W (ORCPT ); Tue, 28 Jun 2022 13:56:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43452 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230398AbiF1R4V (ORCPT ); Tue, 28 Jun 2022 13:56:21 -0400 Received: from mail-pj1-f48.google.com (mail-pj1-f48.google.com [209.85.216.48]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ACCCEF28 for ; Tue, 28 Jun 2022 10:56:20 -0700 (PDT) Received: by mail-pj1-f48.google.com with SMTP id g16-20020a17090a7d1000b001ea9f820449so16705207pjl.5 for ; Tue, 28 Jun 2022 10:56:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=sHR4G3ws2fbNulS0qQml6MSdrD8RGT9jAtN9mD7Rf1A=; b=08+6P8oJ8+O4TSnISdKwb/NXpA7iM+X8gNpM7jwV35O/U/7HQD8fxN28+VWRtC8dAy T+vfRvzkNDOC7d0rArzqYUQS7rkpQNew16+ZHeci4/oagUGOX+w2NMk43MgQ0n7fH2fR 6vSYYhkAqUf3Yb6IyBuE+rgOLvGuIE1e4nI3AuwqA1BGpj8DazwDlOBJhEXkZGUqYvRk kdMCClTVs7F5x684G7kBLWdEivqHjp0M2O8JTOR6Jye3bNpqghW5jfWhovgmB6sqdXzr cnhJtKrdReOCxgw7SZUv9gu+UKBCnWzppxJ1+Z3LD4zy2OnEq52hxzQhqAwcTnmRJUx3 BQ7A== X-Gm-Message-State: AJIora+jZnSS63V1FofqFZyJ0YB2oOa8KbkYrttq7aV3L8tLblIWNjGg m4iT4e99MUWkP4ruu4yuAKU= X-Google-Smtp-Source: AGRyM1tlFI4o9NnLTjhy1FJMzGtqcGYipCdLPwSjSQZx1gs4/Wc57mr6PAuBf+2ocBNAWlTpeGgOng== X-Received: by 2002:a17:90b:2285:b0:1ec:aa3f:8dc1 with SMTP id kx5-20020a17090b228500b001ecaa3f8dc1mr854020pjb.145.1656438980028; Tue, 28 Jun 2022 10:56:20 -0700 (PDT) Received: from bvanassche-linux.mtv.corp.google.com ([2620:15c:211:201:3879:b18f:db0d:205]) by smtp.gmail.com with ESMTPSA id f11-20020a62380b000000b0051829b1595dsm9691725pfa.130.2022.06.28.10.56.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jun 2022 10:56:19 -0700 (PDT) From: Bart Van Assche To: "Martin K . Petersen" Cc: Jaegeuk Kim , linux-scsi@vger.kernel.org, Bart Van Assche , Christoph Hellwig , Ming Lei , Hannes Reinecke , John Garry , Li Zhijian Subject: [PATCH] scsi: core: Call blk_mq_free_tag_set() earlier Date: Tue, 28 Jun 2022 10:56:12 -0700 Message-Id: <20220628175612.2157218-1-bvanassche@acm.org> X-Mailer: git-send-email 2.37.0.rc0.161.g10f37bed90-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org There are two .exit_cmd_priv implementations. Both implementations use the SCSI host pointer. Make sure that the SCSI host pointer is valid when .exit_cmd_priv is called by moving the .exit_cmd_priv calls from scsi_device_dev_release() to scsi_forget_host(). Moving blk_mq_free_tag_set() from scsi_device_dev_release() to scsi_forget_host() is safe because scsi_forget_host() drains all the request queues that use the host tag set. This guarantees that no requests are in flight and also that no new requests will be allocated from the host tag set. This patch fixes the following use-after-free: ================================================================== BUG: KASAN: use-after-free in srp_exit_cmd_priv+0x27/0xd0 [ib_srp] Read of size 8 at addr ffff888100337000 by task multipathd/16727 Call Trace: dump_stack_lvl+0x34/0x44 print_report.cold+0x5e/0x5db kasan_report+0xab/0x120 srp_exit_cmd_priv+0x27/0xd0 [ib_srp] scsi_mq_exit_request+0x4d/0x70 blk_mq_free_rqs+0x143/0x410 __blk_mq_free_map_and_rqs+0x6e/0x100 blk_mq_free_tag_set+0x2b/0x160 scsi_host_dev_release+0xf3/0x1a0 device_release+0x54/0xe0 kobject_put+0xa5/0x120 device_release+0x54/0xe0 kobject_put+0xa5/0x120 scsi_device_dev_release_usercontext+0x4c1/0x4e0 execute_in_process_context+0x23/0x90 device_release+0x54/0xe0 kobject_put+0xa5/0x120 scsi_disk_release+0x3f/0x50 device_release+0x54/0xe0 kobject_put+0xa5/0x120 disk_release+0x17f/0x1b0 device_release+0x54/0xe0 kobject_put+0xa5/0x120 dm_put_table_device+0xa3/0x160 [dm_mod] dm_put_device+0xd0/0x140 [dm_mod] free_priority_group+0xd8/0x110 [dm_multipath] free_multipath+0x94/0xe0 [dm_multipath] dm_table_destroy+0xa2/0x1e0 [dm_mod] __dm_destroy+0x196/0x350 [dm_mod] dev_remove+0x10c/0x160 [dm_mod] ctl_ioctl+0x2c2/0x590 [dm_mod] dm_ctl_ioctl+0x5/0x10 [dm_mod] __x64_sys_ioctl+0xb4/0xf0 dm_ctl_ioctl+0x5/0x10 [dm_mod] __x64_sys_ioctl+0xb4/0xf0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Cc: Christoph Hellwig Cc: Ming Lei Cc: Hannes Reinecke Cc: John Garry Cc: Li Zhijian Reported-by: Li Zhijian Tested-by: Li Zhijian Fixes: 65ca846a5314 ("scsi: core: Introduce {init,exit}_cmd_priv()") Signed-off-by: Bart Van Assche --- drivers/scsi/hosts.c | 10 +++++----- drivers/scsi/scsi_lib.c | 3 +++ 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index ef6c0e37acce..74bfa187fe19 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -182,6 +182,8 @@ void scsi_remove_host(struct Scsi_Host *shost) mutex_unlock(&shost->scan_mutex); scsi_proc_host_rm(shost); + scsi_mq_destroy_tags(shost); + spin_lock_irqsave(shost->host_lock, flags); if (scsi_host_set_state(shost, SHOST_DEL)) BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY)); @@ -295,8 +297,8 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, return error; /* - * Any host allocation in this function will be freed in - * scsi_host_dev_release(). + * Any resources associated with the SCSI host in this function except + * the tag set will be freed by scsi_host_dev_release(). */ out_del_dev: device_del(&shost->shost_dev); @@ -312,6 +314,7 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, pm_runtime_disable(&shost->shost_gendev); pm_runtime_set_suspended(&shost->shost_gendev); pm_runtime_put_noidle(&shost->shost_gendev); + scsi_mq_destroy_tags(shost); fail: return error; } @@ -345,9 +348,6 @@ static void scsi_host_dev_release(struct device *dev) kfree(dev_name(&shost->shost_dev)); } - if (shost->tag_set.tags) - scsi_mq_destroy_tags(shost); - kfree(shost->shost_data); ida_free(&host_index_ida, shost->host_no); diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 6ffc9e4258a8..1aa1a279f8f3 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1990,7 +1990,10 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost) void scsi_mq_destroy_tags(struct Scsi_Host *shost) { + if (!shost->tag_set.tags) + return; blk_mq_free_tag_set(&shost->tag_set); + WARN_ON_ONCE(shost->tag_set.tags); } /**