]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
mm/page_table_check: fix accessing unmapped ptep
authorMiaohe Lin <linmiaohe@huawei.com>
Thu, 26 May 2022 11:33:50 +0000 (19:33 +0800)
committerakpm <akpm@linux-foundation.org>
Fri, 27 May 2022 15:55:18 +0000 (08:55 -0700)
commit24c8e27e63224ce832b4723cb60632d3eddb55de
tree7bfdfa301eb22eacbc930dbfc807823350146848
parent3e35142ef99fe6b4fe5d834ad43ee13cca10a2dc
mm/page_table_check: fix accessing unmapped ptep

ptep is unmapped too early, so ptep could theoretically be accessed while
it's unmapped.  This might become a problem if/when CONFIG_HIGHPTE becomes
available on riscv.

Fix it by deferring pte_unmap() until page table checking is done.

[akpm@linux-foundation.org: account for ptep alteration, per Matthew]
Link: https://lkml.kernel.org/r/20220526113350.30806-1-linmiaohe@huawei.com
Fixes: 80110bbfbba6 ("mm/page_table_check: check entries at pmd levels")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/page_table_check.c