Re: [PATCH] Fix edit on screens with more than 200 columns

["Carsey, Jaben" <jaben.carsey@intel.com>]

That seems good to me.
Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>

Ray, what do you think?

-Jaben


> -----Original Message-----
> From: Witt, Sebastian [mailto:sebastian.witt@siemens.com]
> Sent: Thursday, January 26, 2017 1:01 AM
> To: Carsey, Jaben <jaben.carsey@intel.com>; edk2-devel@lists.01.org
> Subject: RE: [PATCH] Fix edit on screens with more than 200 columns
> Importance: High
> 
> Like this?
> 
> If the shell edit command is used on a screen with more than
> 200 columns, we get a buffer overflow. This always allocates a pool for the
> columns.
> 
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Sebastian Witt <sebastian.witt@siemens.com>
> 
> ---
>  .../UefiShellDebug1CommandsLib.c                          | 15 ++++++++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git
> a/ShellPkg/Library/UefiShellDebug1CommandsLib/UefiShellDebug1Comman
> dsLib.c
> b/ShellPkg/Library/UefiShellDebug1CommandsLib/UefiShellDebug1Comman
> dsLib.c
> index 6ebf002..d81dd01 100644
> ---
> a/ShellPkg/Library/UefiShellDebug1CommandsLib/UefiShellDebug1Comman
> dsLib.c
> +++
> b/ShellPkg/Library/UefiShellDebug1CommandsLib/UefiShellDebug1Comman
> dsLib.c
> @@ -302,12 +302,21 @@ EditorClearLine (
>    IN UINTN LastRow
>    )
>  {
> -  CHAR16 Line[200];
> +  CHAR16 *Line;
> 
>    if (Row == 0) {
>      Row = 1;
>    }
> 
> +  // Allocate buffer for columns
> +  Line = AllocateZeroPool (LastCol*(sizeof(CHAR16) + 1));
> +  if (Line == NULL) {
> +    return;
> +  }
> +
>    //
>    // prepare a blank line
>    //
> @@ -326,6 +335,10 @@ EditorClearLine (
>    // print out the blank line
>    //
>    ShellPrintEx (0, ((INT32)Row) - 1, Line);
> +
> +  FreePool (Line);
>  }
> 
>  /**
> --
> 2.1.4
> 
> 
> -----Original Message-----
> From: Carsey, Jaben [mailto:jaben.carsey@intel.com]
> Sent: Dienstag, 24. Januar 2017 18:36
> To: Witt, Sebastian (DF FA AS DH KHE 1); edk2-devel@lists.01.org
> Cc: Carsey, Jaben
> Subject: RE: [PATCH] Fix edit on screens with more than 200 columns
> 
> I didn't mean a 400 static, I meant start by allocating 400 and simplify the end
> of the function...
> 
> > -----Original Message-----
> > From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of
> > Witt, Sebastian
> > Sent: Tuesday, January 24, 2017 8:48 AM
> > To: Carsey, Jaben <jaben.carsey@intel.com>; edk2-devel@lists.01.org
> > Subject: Re: [edk2] [PATCH] Fix edit on screens with more than 200
> > columns
> > Importance: High
> >
> > Only performance. But I haven't measured if there is a big difference
> > between static buffer and AllocateZeroPool. I wouldn't use a fixed value.
> > There may be a display device with more than 400 columns. Otherwise
> > one can always allocate the [LastCol + 1] buffer.
> >
> > -----Original Message-----
> > From: Carsey, Jaben [mailto:jaben.carsey@intel.com]
> > Sent: Dienstag, 24. Januar 2017 17:27
> > To: Witt, Sebastian (DF FA AS DH KHE 1); edk2-devel@lists.01.org
> > Cc: Carsey, Jaben
> > Subject: RE: [PATCH] Fix edit on screens with more than 200 columns
> >
> > Is there a reason to not just always start with allocating the 400 and
> > then we don't need to complicate the end to conditionally free the buffer?
> >
> > > -----Original Message-----
> > > From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf
> > > Of Witt, Sebastian
> > > Sent: Tuesday, January 24, 2017 5:14 AM
> > > To: edk2-devel@lists.01.org
> > > Subject: [edk2] [PATCH] Fix edit on screens with more than 200
> > > columns
> > > Importance: High
> > >
> > > If the shell edit command is used on a screen with more than
> > > 200 columns, we get a buffer overflow. This increases the default
> > > buffer size to
> > > 400 columns and allocates a pool when this is not enough.
> > >
> > > Contributed-under: TianoCore Contribution Agreement 1.0
> > > Signed-off-by: Sebastian Witt <sebastian.witt@siemens.com>
> > >
> > > ---
> > >  .../UefiShellDebug1CommandsLib.c                          | 15 ++++++++++++++-
> > >  1 file changed, 14 insertions(+), 1 deletion(-)
> > >
> > > diff --git
> > >
> >
> a/ShellPkg/Library/UefiShellDebug1CommandsLib/UefiShellDebug1Comman
> > dsL
> > > i
> > > b.c
> > >
> >
> b/ShellPkg/Library/UefiShellDebug1CommandsLib/UefiShellDebug1Comman
> > dsL
> > > i
> > > b.c
> > > index 6ebf002..d81dd01 100644
> > > ---
> > >
> >
> a/ShellPkg/Library/UefiShellDebug1CommandsLib/UefiShellDebug1Comman
> > dsL
> > > i
> > > b.c
> > > +++
> > >
> >
> b/ShellPkg/Library/UefiShellDebug1CommandsLib/UefiShellDebug1Comman
> > d
> > > +++ sLib.c
> > > @@ -302,12 +302,21 @@ EditorClearLine (
> > >    IN UINTN LastRow
> > >    )
> > >  {
> > > -  CHAR16 Line[200];
> > > +  CHAR16 Buffer[400];
> > > +  CHAR16 *Line = Buffer;
> > >
> > >    if (Row == 0) {
> > >      Row = 1;
> > >    }
> > >
> > > +  // If there are more columns than our buffer can contain,
> > > + allocate new buffer  if (LastCol >= (sizeof (Buffer) / sizeof (CHAR16))) {
> > > +    Line = AllocateZeroPool (LastCol*(sizeof(CHAR16) + 1));
> > > +    if (Line == NULL) {
> > > +      return;
> > > +    }
> > > +  }
> > > +
> > >    //
> > >    // prepare a blank line
> > >    //
> > > @@ -326,6 +335,10 @@ EditorClearLine (
> > >    // print out the blank line
> > >    //
> > >    ShellPrintEx (0, ((INT32)Row) - 1, Line);
> > > +
> > > +  // Free if allocated
> > > +  if (Line != Buffer)
> > > +    FreePool (Line);
> > >  }
> > >
> > >  /**
> > > --
> > > 2.1.4
> > >
> > > With best regards,
> > > Sebastian Witt
> > >
> > > Siemens AG
> > > Digital Factory Division
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