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author | Tony Luck <tony.luck@intel.com> | 2019-01-11 14:46:37 -0800 |
---|---|---|
committer | Dan Williams <dan.j.williams@intel.com> | 2019-01-11 14:50:29 -0800 |
commit | 0919871ac37fdcf46c7657da0f1742efe096b399 (patch) | |
tree | d5cba0cc572ae3f4fd0ccd125e066043b71168a1 /drivers/acpi/nfit | |
parent | 1cb95e072ede5e3d6a54eefd520db21b45985896 (diff) | |
download | linux-0919871ac37fdcf46c7657da0f1742efe096b399.tar.gz linux-0919871ac37fdcf46c7657da0f1742efe096b399.tar.bz2 linux-0919871ac37fdcf46c7657da0f1742efe096b399.zip |
acpi/nfit: Fix race accessing memdev in nfit_get_smbios_id()
Possible race accessing memdev structures after dropping the
mutex. Dan Williams says this could race against another thread
that is doing:
# echo "ACPI0012:00" > /sys/bus/acpi/drivers/nfit/unbind
Reported-by: Jane Chu <jane.chu@oracle.com>
Fixes: 23222f8f8dce ("acpi, nfit: Add function to look up nvdimm...")
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/acpi/nfit')
-rw-r--r-- | drivers/acpi/nfit/core.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 4ae953a5aebf..790691d9a982 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -714,6 +714,7 @@ int nfit_get_smbios_id(u32 device_handle, u16 *flags) struct acpi_nfit_memory_map *memdev; struct acpi_nfit_desc *acpi_desc; struct nfit_mem *nfit_mem; + u16 physical_id; mutex_lock(&acpi_desc_lock); list_for_each_entry(acpi_desc, &acpi_descs, list) { @@ -721,10 +722,11 @@ int nfit_get_smbios_id(u32 device_handle, u16 *flags) list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) { memdev = __to_nfit_memdev(nfit_mem); if (memdev->device_handle == device_handle) { + *flags = memdev->flags; + physical_id = memdev->physical_id; mutex_unlock(&acpi_desc->init_mutex); mutex_unlock(&acpi_desc_lock); - *flags = memdev->flags; - return memdev->physical_id; + return physical_id; } } mutex_unlock(&acpi_desc->init_mutex); |