Re: [PATCH] IOMUX: Fix access past end of console_devices

[Sean Anderson]

On 3/30/22 1:13 PM, Andy Shevchenko wrote:

On Wed, Mar 30, 2022 at 7:49 PM Sean Anderson <sean...@gmail.com> wrote:

Also I don't like to have workarounds for the broken tools.
But if you still want to have something, what about rather this

  #define for_each_console_dev(i, file, dev)             \
-       for (i = 0, dev = console_devices[file][i];     \
-            i < cd_count[file];                        \
-            i++, dev = console_devices[file][i])
+       for (i = 0; i < cd_count[file] &&               \
+               (dev = console_devices[file][i]); i++)

        for (i = 0, dev = console_devices[file][0];     \
             i < cd_count[file];                        \
             i++, dev = console_devices[file][i])

?

Or if it's still complains

        for (i = 0, dev = cd_count[file] ? console_devices[file][0] : NULL;     
\
             i < cd_count[file];                        \
             i++, dev = console_devices[file][i])

?

The problem is not the first assignment but the last. Consider the case when 
cd_count[file] = 1

i = 0, dev = console_devices[file][0]; // OK
i < cd_count[file] // 0 < 1
// loop body
i++, dev = console_devices[file][1] // Oops, past the end
i < cd_count[file] // 1 < 1, loop exit

--Sean