firmware: arm_scpi: Ensure scpi_info is not assigned if the probe fails

commit 689640efc0a2c4e07e6f88affe6d42cd40cc3f85 upstream.

When scpi probe fails, at any point, we need to ensure that the scpi_info
is not set and will remain NULL until the probe succeeds. If it is not
taken care, then it could result use-after-free as the value is exported
via get_scpi_ops() and could refer to a memory allocated via devm_kzalloc()
but freed when the probe fails.

Link: https://lore.kernel.org/r/20220701160310.148344-1-sudeep.holla@arm.com
Cc: stable@vger.kernel.org # 4.19+
Reported-by: huhai <huhai@kylinos.cn>
Reviewed-by: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sudeep Holla 2022-07-01 17:03:10 +01:00 committed by Greg Kroah-Hartman
parent 7c77d1f9ba
commit 18048cba44

View File

@ -815,7 +815,7 @@ static int scpi_init_versions(struct scpi_drvinfo *info)
info->firmware_version = le32_to_cpu(caps.platform_version);
}
/* Ignore error if not implemented */
if (scpi_info->is_legacy && ret == -EOPNOTSUPP)
if (info->is_legacy && ret == -EOPNOTSUPP)
return 0;
return ret;
@ -905,13 +905,14 @@ static int scpi_probe(struct platform_device *pdev)
struct resource res;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct scpi_drvinfo *scpi_drvinfo;
scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
if (!scpi_info)
scpi_drvinfo = devm_kzalloc(dev, sizeof(*scpi_drvinfo), GFP_KERNEL);
if (!scpi_drvinfo)
return -ENOMEM;
if (of_match_device(legacy_scpi_of_match, &pdev->dev))
scpi_info->is_legacy = true;
scpi_drvinfo->is_legacy = true;
count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
if (count < 0) {
@ -919,19 +920,19 @@ static int scpi_probe(struct platform_device *pdev)
return -ENODEV;
}
scpi_info->channels = devm_kcalloc(dev, count, sizeof(struct scpi_chan),
GFP_KERNEL);
if (!scpi_info->channels)
scpi_drvinfo->channels =
devm_kcalloc(dev, count, sizeof(struct scpi_chan), GFP_KERNEL);
if (!scpi_drvinfo->channels)
return -ENOMEM;
ret = devm_add_action(dev, scpi_free_channels, scpi_info);
ret = devm_add_action(dev, scpi_free_channels, scpi_drvinfo);
if (ret)
return ret;
for (; scpi_info->num_chans < count; scpi_info->num_chans++) {
for (; scpi_drvinfo->num_chans < count; scpi_drvinfo->num_chans++) {
resource_size_t size;
int idx = scpi_info->num_chans;
struct scpi_chan *pchan = scpi_info->channels + idx;
int idx = scpi_drvinfo->num_chans;
struct scpi_chan *pchan = scpi_drvinfo->channels + idx;
struct mbox_client *cl = &pchan->cl;
struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
@ -975,45 +976,53 @@ static int scpi_probe(struct platform_device *pdev)
return ret;
}
scpi_info->commands = scpi_std_commands;
scpi_drvinfo->commands = scpi_std_commands;
platform_set_drvdata(pdev, scpi_info);
platform_set_drvdata(pdev, scpi_drvinfo);
if (scpi_info->is_legacy) {
if (scpi_drvinfo->is_legacy) {
/* Replace with legacy variants */
scpi_ops.clk_set_val = legacy_scpi_clk_set_val;
scpi_info->commands = scpi_legacy_commands;
scpi_drvinfo->commands = scpi_legacy_commands;
/* Fill priority bitmap */
for (idx = 0; idx < ARRAY_SIZE(legacy_hpriority_cmds); idx++)
set_bit(legacy_hpriority_cmds[idx],
scpi_info->cmd_priority);
scpi_drvinfo->cmd_priority);
}
ret = scpi_init_versions(scpi_info);
scpi_info = scpi_drvinfo;
ret = scpi_init_versions(scpi_drvinfo);
if (ret) {
dev_err(dev, "incorrect or no SCP firmware found\n");
scpi_info = NULL;
return ret;
}
if (scpi_info->is_legacy && !scpi_info->protocol_version &&
!scpi_info->firmware_version)
if (scpi_drvinfo->is_legacy && !scpi_drvinfo->protocol_version &&
!scpi_drvinfo->firmware_version)
dev_info(dev, "SCP Protocol legacy pre-1.0 firmware\n");
else
dev_info(dev, "SCP Protocol %lu.%lu Firmware %lu.%lu.%lu version\n",
FIELD_GET(PROTO_REV_MAJOR_MASK,
scpi_info->protocol_version),
scpi_drvinfo->protocol_version),
FIELD_GET(PROTO_REV_MINOR_MASK,
scpi_info->protocol_version),
scpi_drvinfo->protocol_version),
FIELD_GET(FW_REV_MAJOR_MASK,
scpi_info->firmware_version),
scpi_drvinfo->firmware_version),
FIELD_GET(FW_REV_MINOR_MASK,
scpi_info->firmware_version),
scpi_drvinfo->firmware_version),
FIELD_GET(FW_REV_PATCH_MASK,
scpi_info->firmware_version));
scpi_info->scpi_ops = &scpi_ops;
scpi_drvinfo->firmware_version));
return devm_of_platform_populate(dev);
scpi_drvinfo->scpi_ops = &scpi_ops;
ret = devm_of_platform_populate(dev);
if (ret)
scpi_info = NULL;
return ret;
}
static const struct of_device_id scpi_of_match[] = {