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authorTony Luck <tony.luck@intel.com>2019-01-11 14:46:37 -0800
committerDan Williams <dan.j.williams@intel.com>2019-01-11 14:50:29 -0800
commit0919871ac37fdcf46c7657da0f1742efe096b399 (patch)
treed5cba0cc572ae3f4fd0ccd125e066043b71168a1 /drivers/acpi
parent1cb95e072ede5e3d6a54eefd520db21b45985896 (diff)
downloadlinux-0919871ac37fdcf46c7657da0f1742efe096b399.tar.bz2
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')
-rw-r--r--drivers/acpi/nfit/core.c6
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);