Re: [PATCH] lib/vsprintf.c: remove leftover 'f' and 'F' cases from bstr_printf()

From: Petr Mladek
Date: Fri Apr 23 2021 - 11:10:27 EST

On Fri 2021-04-23 11:45:29, Rasmus Villemoes wrote:
> Commit 9af7706492f9 ("lib/vsprintf: Remove support for %pF and %pf in
> favour of %pS and %ps") removed support for %pF and %pf, and correctly
> removed the handling of those cases in vbin_printf(). However, the
> corresponding cases in bstr_printf() were left behind.
> In the same series, %pf was re-purposed for dealing with
> fwnodes (3bd32d6a2ee6, "lib/vsprintf: Add %pfw conversion specifier
> for printing fwnode names").
> So should anyone use %pf with the binary printf routines,
> vbin_printf() would (correctly, as it involves dereferencing the
> pointer) do the string formatting to the u32 array, but bstr_printf()
> would not copy the string from the u32 array, but instead interpret
> the first sizeof(void*) bytes of the formatted string as a pointer -
> which generally won't end well (also, all subsequent get_args would be
> out of sync).
> Fixes: 9af7706492f9 ("lib/vsprintf: Remove support for %pF and %pf in favour of %pS and %ps")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>

Great catch!

The patch is pushed in printk/linux.git, branch for-5.13 now.

I did it quickly because the merge window will likely be opened
next week and this should get in.

Best Regards,