commit 46feb6b495f7628a6dbf36c4e6d80faf378372d4 upstream.
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
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 .
 https://marc.info/?l=linux-kernel&m=152449131114778&w=2Signed-off-by: Gustavo A. R. Silva <firstname.lastname@example.org>
Signed-off-by: Bjorn Helgaas <email@example.com>
Acked-by: Logan Gunthorpe <firstname.lastname@example.org>
Signed-off-by: Greg Kroah-Hartman <email@example.com>