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| author | Kelvin Cao <kelvin.cao@microchip.com> | 2020-01-06 20:03:35 +0100 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2020-01-15 18:00:39 +0100 |
| commit | ce7c88600bf8ec0d12cf8e147907f96cd58eeb2e (patch) | |
| tree | fb70df029e2a5eba8485505d199f138c4f626e42 /drivers/pci | |
| parent | PCI/switchtec: Add Gen4 flash information interface support (diff) | |
| download | linux-ce7c88600bf8ec0d12cf8e147907f96cd58eeb2e.tar.xz linux-ce7c88600bf8ec0d12cf8e147907f96cd58eeb2e.zip | |
PCI/switchtec: Add Gen4 MRPC GAS access permission check
Gen4 hardware provides new MRPC commands to read and write directly from
any address in the PCI BAR (which Microsemi refers to as GAS). Since
accessing BARs can be dangerous and break the driver, we don't want
unprivileged users to have this ability.
Therefore, require CAP_SYS_ADMIN for the local and remote GAS access MRPC
commands. Privileged processes will already have access to the BAR through
the sysfs resource file so this doesn't give userspace any capabilities it
didn't already have.
[logang@deltatee.com: rework commit message]
Link: https://lore.kernel.org/r/20200106190337.2428-11-logang@deltatee.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/switch/switchtec.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c index af85d232d200..92b95e8067c0 100644 --- a/drivers/pci/switch/switchtec.c +++ b/drivers/pci/switch/switchtec.c @@ -479,6 +479,12 @@ static ssize_t switchtec_dev_write(struct file *filp, const char __user *data, rc = -EFAULT; goto out; } + if (((MRPC_CMD_ID(stuser->cmd) == MRPC_GAS_WRITE) || + (MRPC_CMD_ID(stuser->cmd) == MRPC_GAS_READ)) && + !capable(CAP_SYS_ADMIN)) { + rc = -EPERM; + goto out; + } data += sizeof(stuser->cmd); rc = copy_from_user(&stuser->data, data, size - sizeof(stuser->cmd)); |