mm: page_alloc: check the order of compound page even when the order is zero
authorHyesoo Yu <hyesoo.yu@samsung.com>
Mon, 23 Oct 2023 08:32:16 +0000 (17:32 +0900)
committerAndrew Morton <akpm@linux-foundation.org>
Wed, 25 Oct 2023 23:47:14 +0000 (16:47 -0700)
commit76f26535d1446373d4735a252ea4247c39d64ba6
tree690e6e660c88d34f6a52be642e71800ee6b5bf16
parentbe16dd764a69752a31096d1a6b2ad775b728b1bd
mm: page_alloc: check the order of compound page even when the order is zero

For compound pages, the head sets the PG_head flag and the tail sets the
compound_head to indicate the head page.  If a user allocates a compound
page and frees it with a different order, the compound page information
will not be properly initialized.  To detect this problem,
compound_order(page) and the order argument are compared, but this is not
checked when the order argument is zero.  That error should be checked
regardless of the order.

Link: https://lkml.kernel.org/r/20231023083217.1866451-1-hyesoo.yu@samsung.com
Signed-off-by: Hyesoo Yu <hyesoo.yu@samsung.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/page_alloc.c