[PATCH 1/2] acpi, nfit: validate commands against the device type

[PATCH 1/2] acpi, nfit: validate commands against the device type

[Dan Williams]

Fix occasions in acpi_nfit_ctl where we check the command type without
validating whether we are parsing dimm vs bus level commands. Where the
command numbers alias between dimms and bus we can make the wrong
assumption just checking the raw command number. For example, with a
simple nfit_test mock up of the clear-error command we trigger the
following:

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000094
    IP: acpi_nfit_ctl+0x29b/0x930 [nfit]
    [..]
    Call Trace:
     nfit_test_probe+0xb85/0xc09 [nfit_test]
     platform_drv_probe+0x3b/0xa0
     ? platform_drv_probe+0x3b/0xa0
     driver_probe_device+0x29c/0x450
     ? test_alloc+0x180/0x180 [nfit_test]
     __driver_attach+0xe3/0xf0
     ? driver_probe_device+0x450/0x450
     bus_for_each_dev+0x73/0xc0
     driver_attach+0x1e/0x20
     bus_add_driver+0x173/0x270
     driver_register+0x60/0xe0
     __platform_driver_register+0x36/0x40
     nfit_test_init+0x2a1/0x1000 [nfit_test]

Fixes: 4b27db7e26cd ("acpi, nfit: add support for the _LSI, _LSR, and...")
Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/acpi/nfit/core.c |   15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 8043bfde7c63..ff2580e7611d 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -483,13 +483,14 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 			min_t(u32, 256, in_buf.buffer.length), true);
 
 	/* call the BIOS, prefer the named methods over _DSM if available */
-	if (cmd == ND_CMD_GET_CONFIG_SIZE && nfit_mem->has_lsi)
+	if (nvdimm && cmd == ND_CMD_GET_CONFIG_SIZE && nfit_mem->has_lsi)
 		out_obj = acpi_label_info(handle);
-	else if (cmd == ND_CMD_GET_CONFIG_DATA && nfit_mem->has_lsr) {
+	else if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && nfit_mem->has_lsr) {
 		struct nd_cmd_get_config_data_hdr *p = buf;
 
 		out_obj = acpi_label_read(handle, p->in_offset, p->in_length);
-	} else if (cmd == ND_CMD_SET_CONFIG_DATA && nfit_mem->has_lsw) {
+	} else if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA
+			&& nfit_mem->has_lsw) {
 		struct nd_cmd_set_config_hdr *p = buf;
 
 		out_obj = acpi_label_write(handle, p->in_offset, p->in_length,
@@ -497,7 +498,7 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 	} else {
 		u8 revid;
 
-		if (nfit_mem)
+		if (nvdimm)
 			revid = nfit_dsm_revid(nfit_mem->family, func);
 		else
 			revid = 1;
@@ -565,8 +566,10 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 	 * Set fw_status for all the commands with a known format to be
 	 * later interpreted by xlat_status().
 	 */
-	if (i >= 1 && ((cmd >= ND_CMD_ARS_CAP && cmd <= ND_CMD_CLEAR_ERROR)
-			|| (cmd >= ND_CMD_SMART && cmd <= ND_CMD_VENDOR)))
+	if (i >= 1 && ((!nvdimm && cmd >= ND_CMD_ARS_CAP
+					&& cmd <= ND_CMD_CLEAR_ERROR)
+				|| (nvdimm && cmd >= ND_CMD_SMART
+					&& cmd <= ND_CMD_VENDOR)))
 		fw_status = *(u32 *) out_obj->buffer.pointer;
 
 	if (offset + in_buf.buffer.length < buf_len) {

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[PATCH 2/2] tools/testing/nvdimm: unit test clear-error commands

[Dan Williams]

Validate command parsing in acpi_nfit_ctl for the clear error command.
This tests for a crash condition introduced by commit 4b27db7e26cd
"acpi, nfit: add support for the _LSI, _LSR, and _LSW label methods".

Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 tools/testing/nvdimm/test/nfit.c |   18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c
index edab68c2e221..7a4846d9607d 100644
--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -1812,6 +1812,7 @@ static int nfit_ctl_test(struct device *dev)
 	unsigned long mask, cmd_size, offset;
 	union {
 		struct nd_cmd_get_config_size cfg_size;
+		struct nd_cmd_clear_error clear_err;
 		struct nd_cmd_ars_status ars_stat;
 		struct nd_cmd_ars_cap ars_cap;
 		char buf[sizeof(struct nd_cmd_ars_status)
@@ -1995,6 +1996,23 @@ static int nfit_ctl_test(struct device *dev)
 		return -EIO;
 	}
 
+	/* test clear error */
+	cmd_size = sizeof(cmds.clear_err);
+	cmds.clear_err = (struct nd_cmd_clear_error) {
+		.length = 512,
+		.cleared = 512,
+	};
+	rc = setup_result(cmds.buf, cmd_size);
+	if (rc)
+		return rc;
+	rc = acpi_nfit_ctl(&acpi_desc->nd_desc, NULL, ND_CMD_CLEAR_ERROR,
+			cmds.buf, cmd_size, &cmd_rc);
+	if (rc < 0 || cmd_rc >= 0) {
+		dev_dbg(dev, "%s: failed at: %d rc: %d cmd_rc: %d\n",
+				__func__, __LINE__, rc, cmd_rc);
+		return -EIO;
+	}
+
 	return 0;
 }
 

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