From 7cd419255d03561d98c94fad1a027a539c4a7484 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Sun, 10 Apr 2016 19:13:13 -0600 Subject: [PATCH] IB/security: Restrict use of the write() interface commit e6bd18f57aad1a2d1ef40e646d03ed0f2515c9e3 upstream. The drivers/infiniband stack uses write() as a replacement for bi-directional ioctl(). This is not safe. There are ways to trigger write calls that result in the return structure that is normally written to user space being shunted off to user specified kernel memory instead. For the immediate repair, detect and deny suspicious accesses to the write API. For long term, update the user space libraries and the kernel API to something that doesn't present the same security vulnerabilities (likely a structured ioctl() interface). The impacted uAPI interfaces are generally only available if hardware from drivers/infiniband is installed in the system. Reported-by: Jann Horn Signed-off-by: Linus Torvalds Signed-off-by: Jason Gunthorpe [ Expanded check to all known write() entry points ] Signed-off-by: Doug Ledford [bwh: Backported to 3.2: - Drop changes to hfi1 - include/rdma/ib.h didn't exist, so create it with the usual header guard and include it in drivers/infiniband/core/ucma.c - ipath_write() has the same problem, so add the same restriction there] Signed-off-by: Ben Hutchings --- Reading git-format-patch failed