linux-kernel - [PATCH 02/12] futex: Extend the FUTEX2 flags

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: <20230728164235.1318118-3-axboe@kernel.dk>
Date:   Fri, 28 Jul 2023 10:42:25 -0600
From:   Jens Axboe <axboe@...nel.dk>
To:     io-uring@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     peterz@...radead.org, andres@...razel.de, tglx@...utronix.de,
        Jens Axboe <axboe@...nel.dk>
Subject: [PATCH 02/12] futex: Extend the FUTEX2 flags

From: Peter Zijlstra <peterz@...radead.org>

Add the definition for the missing but always intended extra sizes,
and add a NUMA flag for the planned numa extention.

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Signed-off-by: Jens Axboe <axboe@...nel.dk>
---
 include/uapi/linux/futex.h | 7 ++++---
 kernel/futex/syscalls.c    | 9 +++++++--
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/include/uapi/linux/futex.h b/include/uapi/linux/futex.h
index 0c5abb6aa8f8..0ed021acc1d9 100644
--- a/include/uapi/linux/futex.h
+++ b/include/uapi/linux/futex.h
@@ -46,10 +46,11 @@
 /*
  * Flags for futex2 syscalls.
  */
-			/*	0x00 */
-			/*	0x01 */
+#define FUTEX2_8		0x00
+#define FUTEX2_16		0x01
 #define FUTEX2_32		0x02
-			/*	0x04 */
+#define FUTEX2_64		0x03
+#define FUTEX2_NUMA		0x04
 			/*	0x08 */
 			/*	0x10 */
 			/*	0x20 */
diff --git a/kernel/futex/syscalls.c b/kernel/futex/syscalls.c
index 42b6c2fac7db..cfc8001e88ea 100644
--- a/kernel/futex/syscalls.c
+++ b/kernel/futex/syscalls.c
@@ -183,7 +183,7 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
 	return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3);
 }
 
-#define FUTEX2_MASK (FUTEX2_32 | FUTEX2_PRIVATE)
+#define FUTEX2_MASK (FUTEX2_64 | FUTEX2_PRIVATE)
 
 /**
  * futex_parse_waitv - Parse a waitv array from userspace
@@ -207,7 +207,12 @@ static int futex_parse_waitv(struct futex_vector *futexv,
 		if ((aux.flags & ~FUTEX2_MASK) || aux.__reserved)
 			return -EINVAL;
 
-		if (!(aux.flags & FUTEX2_32))
+		if (!IS_ENABLED(CONFIG_64BIT) || in_compat_syscall()) {
+			if ((aux.flags & FUTEX2_64) == FUTEX2_64)
+				return -EINVAL;
+		}
+
+		if ((aux.flags & FUTEX2_64) != FUTEX2_32)
 			return -EINVAL;
 
 		futexv[i].w.flags = aux.flags;
-- 
2.40.1