diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-08-16 14:06:46 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-19 22:43:37 +0200 |
| commit | 0fad94cf10165084189bc160cc48f8004ea11ee8 (patch) | |
| tree | ef47d364bce55960c1aadc201a99a21156406ffd | |
| parent | ff225750dc4e70ce5c4288fe3850ae9dc69df024 (diff) | |
switchtec: Fix Spectre v1 vulnerability
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
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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/pci/switch/switchtec.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c index af81b2dec42e..620f5b995a12 100644 --- a/drivers/pci/switch/switchtec.c +++ b/drivers/pci/switch/switchtec.c @@ -24,6 +24,8 @@ #include <linux/cdev.h> #include <linux/wait.h> +#include <linux/nospec.h> + MODULE_DESCRIPTION("Microsemi Switchtec(tm) PCIe Management Driver"); MODULE_VERSION("0.1"); MODULE_LICENSE("GPL"); @@ -1173,6 +1175,8 @@ static int ioctl_port_to_pff(struct switchtec_dev *stdev, default: if (p.port > ARRAY_SIZE(pcfg->dsp_pff_inst_id)) return -EINVAL; + p.port = array_index_nospec(p.port, + ARRAY_SIZE(pcfg->dsp_pff_inst_id) + 1); p.pff = ioread32(&pcfg->dsp_pff_inst_id[p.port - 1]); break; } |