linux/drivers/xen/gntalloc.c
Yousef Alhouseen 2299822f3f xen/gntalloc: validate grant count before allocation
gntalloc_ioctl_alloc() allocates the grant-id array before checking
whether the requested count fits within the global grant limit. Counts
above that limit cannot succeed, so reject them before the
user-controlled allocation reaches kcalloc().

Use a subtraction-based check while holding gref_mutex so adding the
requested count cannot wrap. Also cast the count before advancing the
per-file index so the page-size multiplication is performed in 64-bit
arithmetic.

Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Message-ID: <20260626223805.43781-3-alhouseenyousef@gmail.com>
2026-07-01 09:58:24 +02:00

607 lines
15 KiB