From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Date: Mon, 23 Aug 2021 23:59:21 +0000 (+1000)
Subject: add-mmap_assert_locked-annotations-to-find_vma-fix
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=07a3667ea227e43aa9b71e3b2769a7f5d27ae47c;p=users%2Fjedix%2Flinux-maple.git

add-mmap_assert_locked-annotations-to-find_vma-fix

TOMOYO needs the same protection which get_arg_page() needs.

Link: https://lkml.kernel.org/r/58bb6bf7-a57e-8a40-e74b-39584b415152@i-love.sakura.ne.jp
Cc: Luigi Rizzo <lrizzo@google.com>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
---

diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c
index 98d985895ec8..31af29f669d2 100644
--- a/security/tomoyo/domain.c
+++ b/security/tomoyo/domain.c
@@ -897,6 +897,9 @@ bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
 		      struct tomoyo_page_dump *dump)
 {
 	struct page *page;
+#ifdef CONFIG_MMU
+	int ret;
+#endif
 
 	/* dump->data is released by tomoyo_find_next_domain(). */
 	if (!dump->data) {
@@ -909,11 +912,13 @@ bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
 	/*
 	 * This is called at execve() time in order to dig around
 	 * in the argv/environment of the new proceess
-	 * (represented by bprm).  'current' is the process doing
-	 * the execve().
+	 * (represented by bprm).
 	 */
-	if (get_user_pages_remote(bprm->mm, pos, 1,
-				FOLL_FORCE, &page, NULL, NULL) <= 0)
+	mmap_read_lock(bprm->mm);
+	ret = get_user_pages_remote(bprm->mm, pos, 1,
+				    FOLL_FORCE, &page, NULL, NULL);
+	mmap_read_unlock(bprm->mm);
+	if (ret <= 0)
 		return false;
 #else
 	page = bprm->page[pos / PAGE_SIZE];