CVE-2023-52739

In the Linux kernel, the following vulnerability has been resolved: Fix
page corruption caused by racy check in __free_pages When we upgraded our
kernel, we started seeing some page corruption like the following
consistently: BUG: Bad page state in process ganesha.nfsd pfn:1304ca
page:0000000022261c55 refcount:0 mapcount:-128 mapping:0000000000000000
index:0x0 pfn:0x1304ca flags: 0x17ffffc0000000() raw: 0017ffffc0000000
ffff8a513ffd4c98 ffffeee24b35ec08 0000000000000000 raw: 0000000000000000
0000000000000001 00000000ffffff7f 0000000000000000 page dumped because:
nonzero mapcount CPU: 0 PID: 15567 Comm: ganesha.nfsd Kdump: loaded
Tainted: P B O 5.10.158-1.nutanix.20221209.el7.x86_64 #1 Hardware name:
VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS
6.00 04/05/2016 Call Trace: dump_stack+0x74/0x96 bad_page.cold+0x63/0x94
check_new_page_bad+0x6d/0x80 rmqueue+0x46e/0x970
get_page_from_freelist+0xcb/0x3f0 ? _cond_resched+0x19/0x40
__alloc_pages_nodemask+0x164/0x300 alloc_pages_current+0x87/0xf0
skb_page_frag_refill+0x84/0x110 … Sometimes, it would also show up as
corruption in the free list pointer and cause crashes. After bisecting the
issue, we found the issue started from commit e320d3012d25
(“mm/page_alloc.c: fix freeing non-compound pages”): if
(put_page_testzero(page)) free_the_page(page, order); else if
(!PageHead(page)) while (order-- > 0) free_the_page(page + (1 << order),
order); So the problem is the check PageHead is racy because at this point
we already dropped our reference to the page. So even if we came in with
compound page, the page can already be freed and PageHead can return false
and we will end up freeing all the tail pages causing double free.