]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE
authorDexuan Cui <decui@microsoft.com>
Wed, 29 Oct 2014 10:53:37 +0000 (03:53 -0700)
committerThomas Gleixner <tglx@linutronix.de>
Wed, 29 Oct 2014 09:57:21 +0000 (10:57 +0100)
commitd1cd1210834649ce1ca6bafe5ac25d2f40331343
tree65b33c4cd4408e03045e6111dd17a94b3ed49f38
parentb77e8f435337baa1cd15852fb9db3f6d26cd8eb7
x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE

pte_pfn() returns a PFN of long (32 bits in 32-PAE), so "long <<
PAGE_SHIFT" will overflow for PFNs above 4GB.

Due to this issue, some Linux 32-PAE distros, running as guests on Hyper-V,
with 5GB memory assigned, can't load the netvsc driver successfully and
hence the synthetic network device can't work (we can use the kernel parameter
mem=3000M to work around the issue).

Cast pte_pfn() to phys_addr_t before shifting.

Fixes: "commit d76565344512: x86, mm: Create slow_virt_to_phys()"
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: gregkh@linuxfoundation.org
Cc: linux-mm@kvack.org
Cc: olaf@aepfle.de
Cc: apw@canonical.com
Cc: jasowang@redhat.com
Cc: dave.hansen@intel.com
Cc: riel@redhat.com
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1414580017-27444-1-git-send-email-decui@microsoft.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch/x86/mm/pageattr.c