From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f67.google.com (mail-wm1-f67.google.com [209.85.128.67]) by mx.groups.io with SMTP id smtpd.web10.31.1601933528064505995 for ; Mon, 05 Oct 2020 14:32:08 -0700 Authentication-Results: mx.groups.io; dkim=pass header.i=@gmail.com header.s=20161025 header.b=jyV5eB05; spf=pass (domain: gmail.com, ip: 209.85.128.67, mailfrom: sudipm.mukherjee@gmail.com) Received: by mail-wm1-f67.google.com with SMTP id z22so865357wmi.0 for ; Mon, 05 Oct 2020 14:32:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=o3Ej3LavHo/S663DnWXhpENRkd1MBuaBAhHjxbMV30s=; b=jyV5eB05miHoZqZ0XtU79dn4XyVWl5bBvj4y6c/qdqgb7oUCoG45AZ0/1VbwBHHDP2 qogvIKBEX4MeuFVH/coQvrR5GLJXRAh9RrmQg7F5OtLSQ0XkDqBZg+eN6mPN0GahEi/P pIrlK8rpMeS6zHCSfaBdCWeqWSPy1917Ic2D3bvGzx7M2r3tSXWFeSfPTe7LGRqKcxEL CC24abMJ0KFZ7aK2DG2WMLt1RIRWs85Z0KNaFIssjIQ33xU3VhUg4KJ/HW2lLPChYHrN sEAtCg6AIPjddhnq+cTi6b2Hro/C0jh+12ngjZ6rgM3HgfVv72t5yu+9qfJ8rw5w0/A3 sGWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=o3Ej3LavHo/S663DnWXhpENRkd1MBuaBAhHjxbMV30s=; b=WsR9Mqj+NoD1gEIulERJQpe7QBheVFBsd/zubMlcx9vBclKzh9g/GXjxSmcZd8p9Y2 exy4mxIKA0Zf4P07dE8U7mmVEkBDBvGoEHUWx/9JGPgHEPsHdeOA/XbEN0dq9WDTiSNT YqC1sankf22DWbVuNxKsHipGn+bL9EYg+/ILAHS8Hu7wXBDkmQd3iqkQ8pVx7xOasn34 uNLBjMdBWAv2Xn3uMBpmo96ACbusguOtC8bMdziboRCBgl5sR68kzcEFjpVHe5nn/NIk zJl0FPFtlGnzB2fWyL3jJsgNew7jXxfXTo6SlFl43HSyXBQiVcwMDeb7RuAtY4OP6WPC A7mA== X-Gm-Message-State: AOAM533JWN4Or6JxRNUP+SZ2DLWr8Ez3wOm4GUff/gbrN2aU1wL/uMgg 2VQXZqejS/8fd8mkCz1MrlY= X-Google-Smtp-Source: ABdhPJzZRxNQ/305lZa0njFqzSW0QW0eoQM1oNffk9v2kzF6D9dfQMiMJZvwTogMHAlr2n5+uPeulQ== X-Received: by 2002:a1c:f214:: with SMTP id s20mr1302967wmc.84.1601933526399; Mon, 05 Oct 2020 14:32:06 -0700 (PDT) Return-Path: Received: from localhost.localdomain (host-92-5-241-147.as43234.net. [92.5.241.147]) by smtp.gmail.com with ESMTPSA id q9sm1474013wrd.57.2020.10.05.14.32.05 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 05 Oct 2020 14:32:05 -0700 (PDT) From: Sudip Mukherjee To: Alan Stern , Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, linux-safety@lists.elisa.tech, linux-usb@vger.kernel.org, Sudip Mukherjee Subject: [PATCH] usb: host: ehci-sched: avoid possible NULL dereference Date: Mon, 5 Oct 2020 22:31:49 +0100 Message-Id: <20201005213149.12332-1-sudipm.mukherjee@gmail.com> X-Mailer: git-send-email 2.11.0 find_tt() can return NULL or the error value in ERR_PTR() and dereferencing the return value without checking for the error can lead to a possible dereference of NULL pointer or ERR_PTR(). Signed-off-by: Sudip Mukherjee --- drivers/usb/host/ehci-sched.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index 6dfb242f9a4b..f3fd7e9fe6b2 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -245,6 +245,8 @@ static void reserve_release_intr_bandwidth(struct ehci_hcd *ehci, /* FS/LS bus bandwidth */ if (tt_usecs) { tt = find_tt(qh->ps.udev); + if (IS_ERR_OR_NULL(tt)) + return; if (sign > 0) list_add_tail(&qh->ps.ps_list, &tt->ps_list); else @@ -1338,6 +1340,8 @@ static void reserve_release_iso_bandwidth(struct ehci_hcd *ehci, } tt = find_tt(stream->ps.udev); + if (IS_ERR_OR_NULL(tt)) + return; if (sign > 0) list_add_tail(&stream->ps.ps_list, &tt->ps_list); else -- 2.11.0