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From: Andrey Konovalov <andreyknvl@google.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Robin Murphy <robin.murphy@arm.com>,
	Kees Cook <keescook@chromium.org>,
	Kate Stewart <kstewart@linuxfoundation.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Ingo Molnar <mingo@kernel.org>,
	"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
	Shuah Khan <shuah@kernel.org>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org,
	linux-mm@kvack.org, linux-arch@vger.kernel.org,
	linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Dmitry Vyukov <dvyukov@google.com>,
	Kostya Serebryany <kcc@google.com>,
	Evgeniy Stepanov <eugenis@google.com>,
	Lee Smith <Lee.Smith@arm.com>,
	Ramana Radhakrishnan <Ramana.Radhakrishnan@arm.com>,
	Jacob Bramley <Jacob.Bramley@arm.com>,
	Ruben Ayrapetyan <Ruben.Ayrapetyan@arm.com>,
	Chintan Pandya <cpandya@codeaurora.org>,
	Luc Van Oostenryck <luc.vanoostenryck@gmail.com>,
	Dave Martin <Dave.Martin@arm.com>,
	Kevin Brodsky <kevin.brodsky@arm.com>,
	Szabolcs Nagy <Szabolcs.Nagy@arm.com>,
	Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH v10 06/12] fs, arm64: untag user pointers in copy_mount_options
Date: Fri, 22 Feb 2019 13:53:18 +0100	[thread overview]
Message-ID: <a958e202cdbe6e1bac8a37b7f3d9881d1b22993d.1550839937.git.andreyknvl@google.com> (raw)
In-Reply-To: <cover.1550839937.git.andreyknvl@google.com>

In copy_mount_options a user address is being subtracted from TASK_SIZE.
If the address is lower than TASK_SIZE, the size is calculated to not
allow the exact_copy_from_user() call to cross TASK_SIZE boundary.
However if the address is tagged, then the size will be calculated
incorrectly.

Untag the address before subtracting.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 fs/namespace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/namespace.c b/fs/namespace.c
index a677b59efd74..d4b7adef9204 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2730,7 +2730,7 @@ void *copy_mount_options(const void __user * data)
 	 * the remainder of the page.
 	 */
 	/* copy_from_user cannot cross TASK_SIZE ! */
-	size = TASK_SIZE - (unsigned long)data;
+	size = TASK_SIZE - (unsigned long)untagged_addr(data);
 	if (size > PAGE_SIZE)
 		size = PAGE_SIZE;
 
-- 
2.21.0.rc0.258.g878e2cd30e-goog


  parent reply	other threads:[~2019-02-22 12:53 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-22 12:53 [PATCH v10 00/12] arm64: untag user pointers passed to the kernel Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 01/12] uaccess: add untagged_addr definition for other arches Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 02/12] arm64: untag user pointers in access_ok and __uaccess_mask_ptr Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 03/12] lib, arm64: untag user pointers in strn*_user Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 04/12] mm, arm64: untag user pointers passed to memory syscalls Andrey Konovalov
2019-02-22 23:07   ` Dave Hansen
2019-02-26 14:41     ` Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 05/12] mm, arm64: untag user pointers in mm/gup.c Andrey Konovalov
2019-02-22 12:53 ` Andrey Konovalov [this message]
2019-02-22 23:03   ` [PATCH v10 06/12] fs, arm64: untag user pointers in copy_mount_options Dave Hansen
2019-02-26 14:35     ` Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 07/12] fs, arm64: untag user pointers in fs/userfaultfd.c Andrey Konovalov
2019-02-22 23:05   ` Dave Hansen
2019-02-26 14:39     ` Andrey Konovalov
2019-03-01 16:59       ` Catalin Marinas
2019-03-01 18:37         ` Dave Hansen
2019-03-05 17:47           ` Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 08/12] net, arm64: untag user pointers in tcp_zerocopy_receive Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 09/12] kernel, arm64: untag user pointers in prctl_set_mm* Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 10/12] tracing, arm64: untag user pointers in seq_print_user_ip Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 11/12] arm64: update Documentation/arm64/tagged-pointers.txt Andrey Konovalov
2019-02-22 12:53 ` [PATCH v10 12/12] selftests, arm64: add a selftest for passing tagged pointers to kernel Andrey Konovalov
2019-02-22 15:35 ` [PATCH v10 00/12] arm64: untag user pointers passed to the kernel Szabolcs Nagy
2019-02-22 15:40   ` Andrey Konovalov
2019-02-22 16:10     ` Szabolcs Nagy
2019-02-26 17:00       ` Andrey Konovalov
2019-02-22 22:54 ` Dave Hansen
2019-02-26 17:18   ` Andrey Konovalov
2019-02-26 17:35     ` Dave Hansen
2019-02-26 23:17     ` Luc Van Oostenryck

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