linux-kernel - [PATCH 3.4 169/172] IB/core: don't disallow registering region starting at 0x0

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: <1434443826-4929-169-git-send-email-lizf@kernel.org>
Date:	Tue, 16 Jun 2015 16:37:03 +0800
From:	lizf@...nel.org
To:	stable@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, Yann Droneaud <ydroneaud@...eya.com>,
	Shachar Raindel <raindel@...lanox.com>,
	Jack Morgenstein <jackm@...lanox.com>,
	Or Gerlitz <ogerlitz@...lanox.com>,
	Doug Ledford <dledford@...hat.com>,
	Zefan Li <lizefan@...wei.com>
Subject: [PATCH 3.4 169/172] IB/core: don't disallow registering region starting at 0x0

From: Yann Droneaud <ydroneaud@...eya.com>

3.4.108-rc1 review patch.  If anyone has any objections, please let me know.

------------------

commit 66578b0b2f69659f00b6169e6fe7377c4b100d18 upstream.

In a call to ib_umem_get(), if address is 0x0 and size is
already page aligned, check added in commit 8494057ab5e4
("IB/uverbs: Prevent integer overflow in ib_umem_get address
arithmetic") will refuse to register a memory region that
could otherwise be valid (provided vm.mmap_min_addr sysctl
and mmap_low_allowed SELinux knobs allow userspace to map
something at address 0x0).

This patch allows back such registration: ib_umem_get()
should probably don't care of the base address provided it
can be pinned with get_user_pages().

There's two possible overflows, in (addr + size) and in
PAGE_ALIGN(addr + size), this patch keep ensuring none
of them happen while allowing to pin memory at address
0x0. Anyway, the case of size equal 0 is no more (partially)
handled as 0-length memory region are disallowed by an
earlier check.

Link: http://mid.gmane.org/cover.1428929103.git.ydroneaud@opteya.com
Cc: Shachar Raindel <raindel@...lanox.com>
Cc: Jack Morgenstein <jackm@...lanox.com>
Cc: Or Gerlitz <ogerlitz@...lanox.com>
Signed-off-by: Yann Droneaud <ydroneaud@...eya.com>
Reviewed-by: Sagi Grimberg <sagig@...lanox.com>
Reviewed-by: Haggai Eran <haggaie@...lanox.com>
Signed-off-by: Doug Ledford <dledford@...hat.com>
Signed-off-by: Zefan Li <lizefan@...wei.com>
---
 drivers/infiniband/core/umem.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index 055ebeb..d0254be 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -98,8 +98,8 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
 	 * If the combination of the addr and size requested for this memory
 	 * region causes an integer overflow, return error.
 	 */
-	if ((PAGE_ALIGN(addr + size) <= size) ||
-	    (PAGE_ALIGN(addr + size) <= addr))
+	if (((addr + size) < addr) ||
+	    PAGE_ALIGN(addr + size) < (addr + size))
 		return ERR_PTR(-EINVAL);

 	if (!can_do_mlock())
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/