fuse: convert page array allocation to kcalloc()

fuse_get_user_pages() allocates the temporary pages[] array used by
iov_iter_extract_pages() with the open-coded kzalloc(n * sizeof(*p),
...) form.  max_pages is derived from the inbound iov_iter and is not
bounded at compile time, so the multiplication can overflow on
sufficiently large iter counts; the resulting too-small allocation
would then be written past by iov_iter_extract_pages().

Switch to kcalloc(), which carries the same zero-on-allocation
semantics and adds the standard size_mul overflow check.  No
functional change for non-overflow inputs.

Signed-off-by: William Theesfeld <william@theesfeld.net>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This commit is contained in:
William Theesfeld 2026-06-01 15:29:34 -04:00 • committed by Miklos Szeredi
commit 03728af4ae