diff options
| author | John Garry <john.garry@huawei.com> | 2018-06-08 18:26:33 +0800 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2018-06-18 11:04:28 -0700 |
| commit | fae2a63737e5973f1426bc139935a0f42e232844 (patch) | |
| tree | 92dca3ec97b95f7cc1c2f883aa667006a61626ff /drivers/ata/libahci.c | |
| parent | 9ffc59d57228d74809700be6f7ecb1db10292f05 (diff) | |
libahci: Fix possible Spectre-v1 pmp indexing in ahci_led_store()
Currently smatch warns of possible Spectre-V1 issue in ahci_led_store():
drivers/ata/libahci.c:1150 ahci_led_store() warn: potential spectre issue 'pp->em_priv' (local cap)
Userspace controls @pmp from following callchain:
em_message->store()
->ata_scsi_em_message_store()
-->ap->ops->em_store()
--->ahci_led_store()
After the mask+shift @pmp is effectively an 8b value, which is used to
index into an array of length 8, so sanitize the array index.
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'drivers/ata/libahci.c')
| -rw-r--r-- | drivers/ata/libahci.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c index 965842a08743..09620c2ffa0f 100644 --- a/drivers/ata/libahci.c +++ b/drivers/ata/libahci.c @@ -35,6 +35,7 @@ #include <linux/kernel.h> #include <linux/gfp.h> #include <linux/module.h> +#include <linux/nospec.h> #include <linux/blkdev.h> #include <linux/delay.h> #include <linux/interrupt.h> @@ -1146,10 +1147,12 @@ static ssize_t ahci_led_store(struct ata_port *ap, const char *buf, /* get the slot number from the message */ pmp = (state & EM_MSG_LED_PMP_SLOT) >> 8; - if (pmp < EM_MAX_SLOTS) + if (pmp < EM_MAX_SLOTS) { + pmp = array_index_nospec(pmp, EM_MAX_SLOTS); emp = &pp->em_priv[pmp]; - else + } else { return -EINVAL; + } /* mask off the activity bits if we are in sw_activity * mode, user should turn off sw_activity before setting |