Files
reactos/base
Hermès Bélusca-Maïto 544e8cc292 [WHOAMI] Fix heap corruption causing crashes when displaying user names/groups tables
CORE-20537

- `WhoamiSetTable()`: Specify the correct size for allocating a buffer
  for a NUL-terminated UTF16 string (previously, only half the space for
  the NUL terminator was considered).
  This caused a heap corruption when the corresponding NUL-terminate
  string was then copied into this buffer, and potentially leading to
  reading past the end of the string (since no real NUL terminator
  would be found).

- `WhoamiPrintTable()`: Just make it do what it needs to do: print the
  table and nothing more: no "side-effect" behaviour like table freeing.

- Instead, add a `WhoamiFreeTable()` routine whose purpose is just to
  free the table. And the tables are freed in the routines where they
  have been previously allocated.

- `WhoamiPrintTable()`:
  * Allocate a column-lengths table *ONLY* when needed, i.e. when
    printing the table in "table" format. When printing it in "list"
    format, there is no need to allocate anything and we can instead
    use only a single variable.

  * The old code handling "those pesky ':'" -- used when tables are
    displayed in list format, using: `whoami /all /fo list` -- was buggy,
    because it was patching the table header names, writing a ':' and a
    NUL-terminator past the end of the allocated string buffer (see bug
    described above in `WhoamiSetTable()`). As a result, once the table
    was freed, a heap corruption would happen, leading to a crash.
    Now, displaying the ':' is handled as part of the wprintf()-formatting
    table item string.

  * For developers, two ways of displaying these ':' are proposed:
    the way Windows displays the table in "list" format, where the ':'
    directly follow the item names in the 1st column; and a "nicer" one
    (to my taste!), where all the ':' are vertically aligned -- currently
    disabled.
2026-03-30 21:12:56 +02:00
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