6.15-stable review patch. If anyone has any objections, please let me know.
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From: Mario Limonciello mario.limonciello@amd.com
[ Upstream commit d9db3a941270d92bbd1a6a6b54a10324484f2f2d ]
If setting up smart PC fails for any reason then this can lead to a double free when unloading amd-pmf. This is because dev->buf was freed but never set to NULL and is again freed in amd_pmf_remove().
To avoid subtle allocation bugs in failures leading to a double free change all allocations into device managed allocations.
Fixes: 5b1122fc4995f ("platform/x86/amd/pmf: fix cleanup in amd_pmf_init_smart_pc()") Link: https://lore.kernel.org/r/20250512211154.2510397-2-superm1@kernel.org Signed-off-by: Mario Limonciello mario.limonciello@amd.com Link: https://lore.kernel.org/r/20250522003457.1516679-2-superm1@kernel.org Reviewed-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/x86/amd/pmf/core.c | 3 +- drivers/platform/x86/amd/pmf/tee-if.c | 56 ++++++++++----------------- 2 files changed, 22 insertions(+), 37 deletions(-)
diff --git a/drivers/platform/x86/amd/pmf/core.c b/drivers/platform/x86/amd/pmf/core.c index 96821101ec773..395c011e837f1 100644 --- a/drivers/platform/x86/amd/pmf/core.c +++ b/drivers/platform/x86/amd/pmf/core.c @@ -280,7 +280,7 @@ int amd_pmf_set_dram_addr(struct amd_pmf_dev *dev, bool alloc_buffer) dev_err(dev->dev, "Invalid CPU id: 0x%x", dev->cpu_id); }
- dev->buf = kzalloc(dev->mtable_size, GFP_KERNEL); + dev->buf = devm_kzalloc(dev->dev, dev->mtable_size, GFP_KERNEL); if (!dev->buf) return -ENOMEM; } @@ -493,7 +493,6 @@ static void amd_pmf_remove(struct platform_device *pdev) mutex_destroy(&dev->lock); mutex_destroy(&dev->update_mutex); mutex_destroy(&dev->cb_mutex); - kfree(dev->buf); }
static const struct attribute_group *amd_pmf_driver_groups[] = { diff --git a/drivers/platform/x86/amd/pmf/tee-if.c b/drivers/platform/x86/amd/pmf/tee-if.c index d3bd12ad036ae..027e992b71472 100644 --- a/drivers/platform/x86/amd/pmf/tee-if.c +++ b/drivers/platform/x86/amd/pmf/tee-if.c @@ -358,30 +358,28 @@ static ssize_t amd_pmf_get_pb_data(struct file *filp, const char __user *buf, return -EINVAL;
/* re-alloc to the new buffer length of the policy binary */ - new_policy_buf = memdup_user(buf, length); - if (IS_ERR(new_policy_buf)) - return PTR_ERR(new_policy_buf); + new_policy_buf = devm_kzalloc(dev->dev, length, GFP_KERNEL); + if (!new_policy_buf) + return -ENOMEM; + + if (copy_from_user(new_policy_buf, buf, length)) { + devm_kfree(dev->dev, new_policy_buf); + return -EFAULT; + }
- kfree(dev->policy_buf); + devm_kfree(dev->dev, dev->policy_buf); dev->policy_buf = new_policy_buf; dev->policy_sz = length;
- if (!amd_pmf_pb_valid(dev)) { - ret = -EINVAL; - goto cleanup; - } + if (!amd_pmf_pb_valid(dev)) + return -EINVAL;
amd_pmf_hex_dump_pb(dev); ret = amd_pmf_start_policy_engine(dev); if (ret < 0) - goto cleanup; + return ret;
return length; - -cleanup: - kfree(dev->policy_buf); - dev->policy_buf = NULL; - return ret; }
static const struct file_operations pb_fops = { @@ -532,13 +530,13 @@ int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev) dev->policy_base = devm_ioremap_resource(dev->dev, dev->res); if (IS_ERR(dev->policy_base)) { ret = PTR_ERR(dev->policy_base); - goto err_free_dram_buf; + goto err_cancel_work; }
- dev->policy_buf = kzalloc(dev->policy_sz, GFP_KERNEL); + dev->policy_buf = devm_kzalloc(dev->dev, dev->policy_sz, GFP_KERNEL); if (!dev->policy_buf) { ret = -ENOMEM; - goto err_free_dram_buf; + goto err_cancel_work; }
memcpy_fromio(dev->policy_buf, dev->policy_base, dev->policy_sz); @@ -546,21 +544,21 @@ int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev) if (!amd_pmf_pb_valid(dev)) { dev_info(dev->dev, "No Smart PC policy present\n"); ret = -EINVAL; - goto err_free_policy; + goto err_cancel_work; }
amd_pmf_hex_dump_pb(dev);
- dev->prev_data = kzalloc(sizeof(*dev->prev_data), GFP_KERNEL); + dev->prev_data = devm_kzalloc(dev->dev, sizeof(*dev->prev_data), GFP_KERNEL); if (!dev->prev_data) { ret = -ENOMEM; - goto err_free_policy; + goto err_cancel_work; }
for (i = 0; i < ARRAY_SIZE(amd_pmf_ta_uuid); i++) { ret = amd_pmf_tee_init(dev, &amd_pmf_ta_uuid[i]); if (ret) - goto err_free_prev_data; + goto err_cancel_work;
ret = amd_pmf_start_policy_engine(dev); switch (ret) { @@ -575,7 +573,7 @@ int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev) default: ret = -EINVAL; amd_pmf_tee_deinit(dev); - goto err_free_prev_data; + goto err_cancel_work; }
if (status) @@ -584,7 +582,7 @@ int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev)
if (!status && !pb_side_load) { ret = -EINVAL; - goto err_free_prev_data; + goto err_cancel_work; }
if (pb_side_load) @@ -600,12 +598,6 @@ int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev) if (pb_side_load && dev->esbin) amd_pmf_remove_pb(dev); amd_pmf_tee_deinit(dev); -err_free_prev_data: - kfree(dev->prev_data); -err_free_policy: - kfree(dev->policy_buf); -err_free_dram_buf: - kfree(dev->buf); err_cancel_work: cancel_delayed_work_sync(&dev->pb_work);
@@ -621,11 +613,5 @@ void amd_pmf_deinit_smart_pc(struct amd_pmf_dev *dev) amd_pmf_remove_pb(dev);
cancel_delayed_work_sync(&dev->pb_work); - kfree(dev->prev_data); - dev->prev_data = NULL; - kfree(dev->policy_buf); - dev->policy_buf = NULL; - kfree(dev->buf); - dev->buf = NULL; amd_pmf_tee_deinit(dev); }