From: "Luck, Tony" <tony.luck@intel.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: linux-nvdimm <linux-nvdimm@lists.01.org>
Subject: [PATCH] acpi/nfit: Fix race accessing memdev in nfit_get_smbios_id()
Date: Fri, 11 Jan 2019 14:46:37 -0800 [thread overview]
Message-ID: <20190111224637.GA7300@agluck-desk> (raw)
In-Reply-To: <CAPcyv4iv5GdmdoCmz4QNz9r6e-GxOPBK-tekJkio_AzhoFKErQ@mail.gmail.com>
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>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---
This time with a commit message and credit to Jane for finding it.
drivers/acpi/nfit/core.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 011d3db19c80..22945bf803c8 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -721,6 +721,7 @@ 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) {
@@ -728,10 +729,11 @@ 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);
--
2.19.1
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next prev parent reply other threads:[~2019-01-11 22:46 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-11 21:43 23222f8f8dce6: acpi, nfit: Add function to look up nvdimm device and provide SMBIOS handle Jane Chu
2019-01-11 21:54 ` Luck, Tony
2019-01-11 22:03 ` Jane Chu
2019-01-11 22:07 ` Dan Williams
2019-01-11 22:12 ` Luck, Tony
2019-01-11 22:21 ` Dan Williams
2019-01-11 22:46 ` Luck, Tony [this message]
2019-01-11 23:06 ` [PATCH] acpi/nfit: Fix race accessing memdev in nfit_get_smbios_id() Dan Williams
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