3.2.70-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Yann Droneaud <ydrone...@opteya.com> 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.ydrone...@opteya.com Cc: Shachar Raindel <rain...@mellanox.com> Cc: Jack Morgenstein <ja...@mellanox.com> Cc: Or Gerlitz <ogerl...@mellanox.com> Signed-off-by: Yann Droneaud <ydrone...@opteya.com> Reviewed-by: Sagi Grimberg <sa...@mellanox.com> Reviewed-by: Haggai Eran <hagg...@mellanox.com> Signed-off-by: Doug Ledford <dledf...@redhat.com> Signed-off-by: Ben Hutchings <b...@decadent.org.uk> --- drivers/infiniband/core/umem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -101,8 +101,8 @@ struct ib_umem *ib_umem_get(struct ib_uc * 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()) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/