]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
switchtec: Fix Spectre v1 vulnerability
authorGustavo A. R. Silva <gustavo@embeddedor.com>
Thu, 16 Aug 2018 19:06:46 +0000 (14:06 -0500)
committerBjorn Helgaas <bhelgaas@google.com>
Tue, 11 Sep 2018 13:47:40 +0000 (08:47 -0500)
commit46feb6b495f7628a6dbf36c4e6d80faf378372d4
treea4118efdd6112248604eab81f3e8930bb0d69601
parent50ca031b51106b1b46162d4e9ecccb7edc95682f
switchtec: Fix Spectre v1 vulnerability

p.port can is indirectly controlled by user-space, hence leading to
a potential exploitation of the Spectre variant 1 vulnerability.

This issue was detected with the help of Smatch:

  drivers/pci/switch/switchtec.c:912 ioctl_port_to_pff() warn: potential spectre issue 'pcfg->dsp_pff_inst_id' [r]

Fix this by sanitizing p.port before using it to index
pcfg->dsp_pff_inst_id

Notice that given that speculation windows are large, the policy is to kill
the speculation on the first load and not worry if it can be completed with
a dependent load/store [1].

[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Logan Gunthorpe <logang@deltatee.com>
Cc: stable@vger.kernel.org
drivers/pci/switch/switchtec.c