Re: [PATCH] USB: EHCI: fix dereference of ERR_PTR

From	Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] USB: EHCI: fix dereference of ERR_PTR
Date	2015-09-21 07:00 +0200
Message-ID	<qb1mO-4P7-5@gated-at.bofh.it> (permalink)
References	<q9lzk-6Gb-31@gated-at.bofh.it> <qaZkZ-1XG-1@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Mon, Sep 21, 2015 at 10:48:52AM +0800, Lu, Baolu wrote:
> 
> 
> On 09/16/2015 10:08 PM, Sudip Mukherjee wrote:
> >On error find_tt() returns either a NULL pointer or the error value in
> >ERR_PTR. But we were dereferencing it directly without even checking if
> >find_tt() returned a valid pointer or not.
> >
> >Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> >---
> >  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 f9a3327..27bced7 100644
> >--- a/drivers/usb/host/ehci-sched.c
> >+++ b/drivers/usb/host/ehci-sched.c
> >@@ -257,6 +257,8 @@ static void reserve_release_intr_bandwidth(struct ehci_hcd *ehci,
> >  	/* FS/LS bus bandwidth */
> >  	if (tt_usecs) {
> >  		tt = find_tt(qh->ps.udev);
> >+		if (!tt || IS_ERR(tt))
> 
> Why not IS_ERR_OR_NULL()?
This was v1, corrected in v2. And Alan has already explained why this
patch is not required.

regards
sudip
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[PATCH] USB: EHCI: fix dereference of ERR_PTR Sudip Mukherjee <sudipm.mukherjee@gmail.com> - 2015-09-16 16:10 +0200
  Re: [PATCH] USB: EHCI: fix dereference of ERR_PTR Fabio Estevam <festevam@gmail.com> - 2015-09-16 16:20 +0200
  Re: [PATCH] USB: EHCI: fix dereference of ERR_PTR Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2015-09-16 16:30 +0200
  [PATCH v2] USB: EHCI: fix dereference of ERR_PTR Sudip Mukherjee <sudipm.mukherjee@gmail.com> - 2015-09-16 18:30 +0200
    Re: [PATCH v2] USB: EHCI: fix dereference of ERR_PTR Alan Stern <stern@rowland.harvard.edu> - 2015-09-16 19:00 +0200
      Re: [PATCH v2] USB: EHCI: fix dereference of ERR_PTR Sudip Mukherjee <sudipm.mukherjee@gmail.com> - 2015-09-18 07:50 +0200
        Re: [PATCH v2] USB: EHCI: fix dereference of ERR_PTR Alan Stern <stern@rowland.harvard.edu> - 2015-09-18 16:50 +0200
  Re: [PATCH] USB: EHCI: fix dereference of ERR_PTR "Lu, Baolu" <baolu.lu@linux.intel.com> - 2015-09-21 04:50 +0200
    Re: [PATCH] USB: EHCI: fix dereference of ERR_PTR Sudip Mukherjee <sudipm.mukherjee@gmail.com> - 2015-09-21 07:00 +0200

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