linux-hardening - [RFC v1 07/17] gup: add non-caching get_user call to fault_in

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250712192202.707192-8-gatlin.newhouse@gmail.com>
Date: Sat, 12 Jul 2025 19:21:52 +0000
From: Gatlin Newhouse <gatlin.newhouse@...il.com>
To: linux-hardening@...r.kernel.org
Cc: Gatlin Newhouse <gatlin.newhouse@...il.com>
Subject: [RFC v1 07/17] gup: add non-caching get_user call to fault_in_readable()

Adds non-caching call to fault_in_readable() for configurations with
SafeFetch enabled and disabled readable pages.
---
 mm/gup.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mm/gup.c b/mm/gup.c
index 3c39cbbeebef..69d2d110da3f 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2224,7 +2224,11 @@ size_t fault_in_readable(const char __user *uaddr, size_t size)
 
 	/* Stop once we overflow to 0. */
 	for (cur = start; cur && cur < end; cur = PAGE_ALIGN_DOWN(cur + PAGE_SIZE))
+#if defined(CONFIG_SAFEFETCH) && !defined(SAFEFETCH_PROTECT_PAGES_READABLE)
+		unsafe_get_user_no_dfcache(c, (const char __user *)cur, out);
+#else
 		unsafe_get_user(c, (const char __user *)cur, out);
+#endif
 out:
 	user_read_access_end();
 	(void)c;
-- 
2.25.1