From: Arnd Bergmann <arnd@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>,
Christoph Hellwig <hch@lst.de>,
linux-arch@vger.kernel.org, linux-mm@kvack.org,
linux-api@vger.kernel.org, arnd@arndb.de,
linux-kernel@vger.kernel.org
Cc: mark.rutland@arm.com, dalias@libc.org,
linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org,
peterz@infradead.org, jcmvbkbc@gmail.com, guoren@kernel.org,
sparclinux@vger.kernel.org, linux-hexagon@vger.kernel.org,
linux-riscv@lists.infradead.org, will@kernel.org,
ardb@kernel.org, linux-s390@vger.kernel.org,
bcain@codeaurora.org, deller@gmx.de, x86@kernel.org,
linux@armlinux.org.uk, linux-csky@vger.kernel.org,
mingo@redhat.com, geert@linux-m68k.org,
linux-snps-arc@lists.infradead.org,
linux-xtensa@linux-xtensa.org, hca@linux.ibm.com,
linux-alpha@vger.kernel.org, linux-um@lists.infradead.org,
linux-m68k@lists.linux-m68k.org, openrisc@lists.librecores.org,
green.hu@gmail.com, shorne@gmail.com,
linux-arm-kernel@lists.infradead.org, monstr@monstr.eu,
tsbogend@alpha.franken.de, linux-parisc@vger.kernel.org,
nickhu@andestech.com, linux-mips@vger.kernel.org,
stable@vger.kernel.org, dinguyen@kernel.org,
David Laight <David.Laight@aculab.com>,
ebiederm@xmission.com, richard@nod.at, akpm@linux-foundation.org,
linuxppc-dev@lists.ozlabs.org, davem@davemloft.net
Subject: [PATCH 01/14] uaccess: fix integer overflow on access_ok()
Date: Mon, 14 Feb 2022 17:34:39 +0100 [thread overview]
Message-ID: <20220214163452.1568807-2-arnd@kernel.org> (raw)
In-Reply-To: <20220214163452.1568807-1-arnd@kernel.org>
From: Arnd Bergmann <arnd@arndb.de>
Three architectures check the end of a user access against the
address limit without taking a possible overflow into account.
Passing a negative length or another overflow in here returns
success when it should not.
Use the most common correct implementation here, which optimizes
for a constant 'size' argument, and turns the common case into a
single comparison.
Cc: stable@vger.kernel.org
Fixes: da551281947c ("csky: User access")
Fixes: f663b60f5215 ("microblaze: Fix uaccess_ok macro")
Fixes: 7567746e1c0d ("Hexagon: Add user access functions")
Reported-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
arch/csky/include/asm/uaccess.h | 7 +++----
arch/hexagon/include/asm/uaccess.h | 18 +++++++++---------
arch/microblaze/include/asm/uaccess.h | 19 ++++---------------
3 files changed, 16 insertions(+), 28 deletions(-)
diff --git a/arch/csky/include/asm/uaccess.h b/arch/csky/include/asm/uaccess.h
index c40f06ee8d3e..ac5a54f57d40 100644
--- a/arch/csky/include/asm/uaccess.h
+++ b/arch/csky/include/asm/uaccess.h
@@ -3,14 +3,13 @@
#ifndef __ASM_CSKY_UACCESS_H
#define __ASM_CSKY_UACCESS_H
-#define user_addr_max() \
- (uaccess_kernel() ? KERNEL_DS.seg : get_fs().seg)
+#define user_addr_max() (current_thread_info()->addr_limit.seg)
static inline int __access_ok(unsigned long addr, unsigned long size)
{
- unsigned long limit = current_thread_info()->addr_limit.seg;
+ unsigned long limit = user_addr_max();
- return ((addr < limit) && ((addr + size) < limit));
+ return (size <= limit) && (addr <= (limit - size));
}
#define __access_ok __access_ok
diff --git a/arch/hexagon/include/asm/uaccess.h b/arch/hexagon/include/asm/uaccess.h
index ef5bfef8d490..719ba3f3c45c 100644
--- a/arch/hexagon/include/asm/uaccess.h
+++ b/arch/hexagon/include/asm/uaccess.h
@@ -25,17 +25,17 @@
* Returns true (nonzero) if the memory block *may* be valid, false (zero)
* if it is definitely invalid.
*
- * User address space in Hexagon, like x86, goes to 0xbfffffff, so the
- * simple MSB-based tests used by MIPS won't work. Some further
- * optimization is probably possible here, but for now, keep it
- * reasonably simple and not *too* slow. After all, we've got the
- * MMU for backup.
*/
+#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
+#define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE)
-#define __access_ok(addr, size) \
- ((get_fs().seg == KERNEL_DS.seg) || \
- (((unsigned long)addr < get_fs().seg) && \
- (unsigned long)size < (get_fs().seg - (unsigned long)addr)))
+static inline int __access_ok(unsigned long addr, unsigned long size)
+{
+ unsigned long limit = TASK_SIZE;
+
+ return (size <= limit) && (addr <= (limit - size));
+}
+#define __access_ok __access_ok
/*
* When a kernel-mode page fault is taken, the faulting instruction
diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h
index d2a8ef9f8978..5b6e0e7788f4 100644
--- a/arch/microblaze/include/asm/uaccess.h
+++ b/arch/microblaze/include/asm/uaccess.h
@@ -39,24 +39,13 @@
# define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
-static inline int access_ok(const void __user *addr, unsigned long size)
+static inline int __access_ok(unsigned long addr, unsigned long size)
{
- if (!size)
- goto ok;
+ unsigned long limit = user_addr_max();
- if ((get_fs().seg < ((unsigned long)addr)) ||
- (get_fs().seg < ((unsigned long)addr + size - 1))) {
- pr_devel("ACCESS fail at 0x%08x (size 0x%x), seg 0x%08x\n",
- (__force u32)addr, (u32)size,
- (u32)get_fs().seg);
- return 0;
- }
-ok:
- pr_devel("ACCESS OK at 0x%08x (size 0x%x), seg 0x%08x\n",
- (__force u32)addr, (u32)size,
- (u32)get_fs().seg);
- return 1;
+ return (size <= limit) && (addr <= (limit - size));
}
+#define access_ok(addr, size) __access_ok((unsigned long)addr, size)
# define __FIXUP_SECTION ".section .fixup,\"ax\"\n"
# define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n"
--
2.29.2
next prev parent reply other threads:[~2022-02-14 16:37 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-14 16:34 [PATCH 00/14] clean up asm/uaccess.h, kill set_fs for good Arnd Bergmann
2022-02-14 16:34 ` Arnd Bergmann [this message]
2022-02-14 16:58 ` [PATCH 01/14] uaccess: fix integer overflow on access_ok() Christoph Hellwig
2022-02-14 16:34 ` [PATCH 02/14] sparc64: add __{get,put}_kernel_nocheck() Arnd Bergmann
2022-02-14 16:34 ` [PATCH 03/14] nds32: fix access_ok() checks in get/put_user Arnd Bergmann
2022-02-14 17:01 ` Christoph Hellwig
2022-02-14 17:10 ` David Laight
2022-02-15 9:18 ` Arnd Bergmann
2022-02-15 10:25 ` Greg KH
2022-02-14 16:34 ` [PATCH 04/14] x86: use more conventional access_ok() definition Arnd Bergmann
2022-02-14 17:02 ` Christoph Hellwig
2022-02-14 19:45 ` Arnd Bergmann
2022-02-14 20:00 ` Christoph Hellwig
2022-02-14 20:01 ` Linus Torvalds
2022-02-14 20:17 ` Al Viro
2022-02-15 2:47 ` Al Viro
2022-02-14 20:24 ` Linus Torvalds
2022-02-14 22:13 ` David Laight
2022-02-14 16:34 ` [PATCH 05/14] uaccess: add generic __{get,put}_kernel_nofault Arnd Bergmann
2022-02-14 17:02 ` Christoph Hellwig
2022-02-15 0:31 ` Al Viro
2022-02-15 13:16 ` Arnd Bergmann
2022-02-14 16:34 ` [PATCH 06/14] mips: use simpler access_ok() Arnd Bergmann
2022-02-14 16:34 ` [PATCH 07/14] uaccess: generalize access_ok() Arnd Bergmann
2022-02-14 17:04 ` Christoph Hellwig
2022-02-14 17:15 ` Al Viro
2022-02-14 19:25 ` Arnd Bergmann
2022-02-15 10:58 ` Mark Rutland
2022-02-14 16:34 ` [PATCH 08/14] arm64: simplify access_ok() Arnd Bergmann
2022-02-14 21:06 ` Robin Murphy
2022-02-15 8:17 ` Ard Biesheuvel
2022-02-15 9:12 ` Arnd Bergmann
2022-02-15 9:21 ` Ard Biesheuvel
2022-02-15 9:39 ` Arnd Bergmann
2022-02-15 10:39 ` Mark Rutland
2022-02-15 10:37 ` Mark Rutland
2022-02-16 19:43 ` Christophe Leroy
2022-02-15 9:30 ` David Laight
2022-02-15 11:24 ` Mark Rutland
2022-02-15 11:07 ` Mark Rutland
2022-02-14 16:34 ` [PATCH 09/14] m68k: drop custom __access_ok() Arnd Bergmann
2022-02-15 0:37 ` Al Viro
2022-02-15 6:29 ` Christoph Hellwig
2022-02-15 7:13 ` Al Viro
2022-02-15 10:02 ` Arnd Bergmann
2022-02-15 13:28 ` David Laight
2022-02-14 16:34 ` [PATCH 10/14] uaccess: remove most CONFIG_SET_FS users Arnd Bergmann
2022-02-14 17:06 ` Christoph Hellwig
2022-02-14 19:40 ` Arnd Bergmann
2022-02-14 16:34 ` [PATCH 11/14] sparc64: remove CONFIG_SET_FS support Arnd Bergmann
2022-02-14 17:06 ` Christoph Hellwig
2022-02-16 13:06 ` Arnd Bergmann
2022-02-15 0:48 ` Al Viro
2022-02-16 13:07 ` Arnd Bergmann
2022-02-14 16:34 ` [PATCH 12/14] sh: " Arnd Bergmann
2022-02-14 16:34 ` [PATCH 13/14] ia64: " Arnd Bergmann
2022-02-14 16:34 ` [PATCH 14/14] uaccess: drop set_fs leftovers Arnd Bergmann
2022-02-15 3:03 ` Al Viro
2022-02-15 7:46 ` Helge Deller
2022-02-15 8:10 ` Arnd Bergmann
2022-02-14 17:35 ` [PATCH 00/14] clean up asm/uaccess.h, kill set_fs for good Linus Torvalds
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