* Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> lm90_detect_nuvoton() is supposed to return NULL if it can not detect
> a chip, or a pointer to the chip name if it does. Under some circumstances
> it returns an error pointer instead. Some versions of gcc interpret an
> ERR_PTR as region of size 0 and generate an error message.
>
> In function ‘__fortify_strlen’,
> inlined from ‘strlcpy’ at ./include/linux/fortify-string.h:159:10,
> inlined from ‘lm90_detect’ at drivers/hwmon/lm90.c:2550:2:
> ./include/linux/fortify-string.h:50:33: error:
> ‘__builtin_strlen’ reading 1 or more bytes from a region of size 0
> 50 | #define __underlying_strlen __builtin_strlen
> | ^
> ./include/linux/fortify-string.h:141:24: note:
> in expansion of macro ‘__underlying_strlen’
> 141 | return __underlying_strlen(p);
> | ^~~~~~~~~~~~~~~~~~~
>
> Returning NULL instead of ERR_PTR() fixes the problem.
>
> Fixes: c7cebce984a2 ("hwmon: (lm90) Rework detect function")
> Reported-by: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Tested-by: Ingo Molnar <mingo@xxxxxxxxxx>
Thanks,
Ingo
