From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x226ljoa+mLH7gE3N63rDbKh2i/0WSjIWJZUUAG8RKBB9Yuwt/dj2zcZewObcoluuqVKL6K1W ARC-Seal: i=1; a=rsa-sha256; t=1518709058; cv=none; d=google.com; s=arc-20160816; b=LhIBxCu8B+b1ovdCD8PSdNQhJVB/3ke0UJdSYc7nFHiElY1Z/6v3ZdXpoNcZUUf+Tc Y9SBEecvh9Pi6PWu0PV4Z1z6BCRwMeNHceVa8vdsMJfUwuEtl/50d5JTviV61PdVi8pE g5nNsh8kpu+HvuohnQcHElsPiCk8sPzkEQGLAqHby9yY4NwayriZCPT3LZv3BtdPBK3P HcZ/JXseADq62e34dC52o9YE7ZVDn2Q/WkeNn/QxUZUqpiowHjHQPCDgeTMe1OqwrSiB lvYpcXci1Q2D2Q3S0sXf9SsimdQ/YValfoMLpgqCpkNyOcuXCvPD3GFls1EV6RfvynBn 0qyg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=ebWREoD0SfnD144cXBcXXHN35WUGS4CbDILRhEa3FXg=; b=cIf2Ob27juBgwLbll/rVyNio36A2gm/kI+NoWlDP96yf2TjYO63B4saAylchUyB4ra 3LdrxyRTzpYtDrMP+nm1xxX3X47z/daeuEnXpRDMTNYQgmy2ddqhqWIgahOg3aqVB5y9 UHId6nTYTU2FiklUTvzJpj6I2nPPARK4Duu24iS2HOrJBBGIoFuCNgrmy7ezKLD5U8dl wk0qgGdS/z/WTz7VUGPSFCOYPFNQPg5K50Q8QAaIX7gpuoQqRPA04dhOcduHYO/jGWq9 xW8neauZEGUjjugyvPwCOAidEeUlwzreM1YG4w15coJYkYQG80t7Pf+ERYiCiLIs9ks5 vbfg== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Maciej S. Szmigiero" , Bart Van Assche , Jens Axboe Subject: [PATCH 4.14 177/195] pktcdvd: Fix a recently introduced NULL pointer dereference Date: Thu, 15 Feb 2018 16:17:48 +0100 Message-Id: <20180215151714.930054744@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180215151705.738773577@linuxfoundation.org> References: <20180215151705.738773577@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1592481870261874904?= X-GMAIL-MSGID: =?utf-8?q?1592481870261874904?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bart Van Assche commit 882d4171a8950646413b1a3cbe0e4a6a612fe82e upstream. Call bdev_get_queue(bdev) after bdev->bd_disk has been initialized instead of just before that pointer has been initialized. This patch avoids that the following command pktsetup 1 /dev/sr0 triggers the following kernel crash: BUG: unable to handle kernel NULL pointer dereference at 0000000000000548 IP: pkt_setup_dev+0x2db/0x670 [pktcdvd] CPU: 2 PID: 724 Comm: pktsetup Not tainted 4.15.0-rc4-dbg+ #1 Call Trace: pkt_ctl_ioctl+0xce/0x1c0 [pktcdvd] do_vfs_ioctl+0x8e/0x670 SyS_ioctl+0x3c/0x70 entry_SYSCALL_64_fastpath+0x23/0x9a Reported-by: Maciej S. Szmigiero Fixes: commit ca18d6f769d2 ("block: Make most scsi_req_init() calls implicit") Signed-off-by: Bart Van Assche Tested-by: Maciej S. Szmigiero Cc: Maciej S. Szmigiero Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/block/pktcdvd.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -2579,14 +2579,14 @@ static int pkt_new_dev(struct pktcdvd_de bdev = bdget(dev); if (!bdev) return -ENOMEM; + ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY, NULL); + if (ret) + return ret; if (!blk_queue_scsi_passthrough(bdev_get_queue(bdev))) { WARN_ONCE(true, "Attempt to register a non-SCSI queue\n"); - bdput(bdev); + blkdev_put(bdev, FMODE_READ | FMODE_NDELAY); return -EINVAL; } - ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY, NULL); - if (ret) - return ret; /* This is safe, since we have a reference from open(). */ __module_get(THIS_MODULE);