(components/fatfs): possible array index out of bounds (IDFGH-14474)

[safocl]

Answers checklist.

• I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
• I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
• I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

The functions in components/fatfs/diskio/diskio_wl.c potentially may produce access to out of bounds of ff_wl_handles array:

esp-idf/components/fatfs/diskio/diskio_wl.c

Line 35 in 0f0068f

wl_handle_t wl_handle = ff_wl_handles[pdrv];

(and other lines)

ff_wl_handles array defined here:

esp-idf/components/fatfs/diskio/diskio_wl.c

Line 18 in 0f0068f

wl_handle_t ff_wl_handles[FF_VOLUMES] = {

pdrv is a function argument and it is not checked to be less than FF_VOLUMES value (that puts from the configuration files).

[safocl]

this check exists here.

esp-idf/components/fatfs/diskio/diskio_wl.c

Line 86 in 0f0068f

if (pdrv >= FF_VOLUMES) {