path: root/drivers/infiniband/core/umem.c
diff options
authorYann Droneaud <ydroneaud@opteya.com>2015-04-13 14:56:23 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-05-06 21:56:27 +0200
commitd016c609f3165cfca74504c55ae55b2030d8a9e3 (patch)
tree63c68dfe0fd99e479277f3bd2a38e7d91931e75a /drivers/infiniband/core/umem.c
parentb55c80ba21ce7cd6aed4323c2b86552434b44fd6 (diff)
IB/core: don't disallow registering region starting at 0x0
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@mellanox.com> Cc: Jack Morgenstein <jackm@mellanox.com> Cc: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Haggai Eran <haggaie@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/infiniband/core/umem.c')
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index dccb9aac35c3..c1fef27010d4 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -101,8 +101,8 @@ 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())