From: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
To: Alan Stern <stern@rowland.harvard.edu>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org, linux-safety@lists.elisa.tech,
linux-usb@vger.kernel.org,
Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Subject: [PATCH] usb: host: ehci-sched: avoid possible NULL dereference
Date: Mon, 5 Oct 2020 22:31:49 +0100 [thread overview]
Message-ID: <20201005213149.12332-1-sudipm.mukherjee@gmail.com> (raw)
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 <sudipm.mukherjee@gmail.com>
---
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
next reply other threads:[~2020-10-05 21:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-05 21:31 Sudip Mukherjee [this message]
2020-10-05 23:19 ` [PATCH] usb: host: ehci-sched: avoid possible NULL dereference Harley A.W. Lorenzo
2020-10-06 1:25 ` stern
2020-10-06 17:58 ` Alan Stern
2020-10-06 7:19 ` gregkh
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