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authorRoss Lagerwall <ross.lagerwall@citrix.com>2019-01-28 10:04:23 +0000
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-02-20 10:34:03 +0100
commit1c0d9b1c31d19d3aa90296a184e4624545d7d1ee (patch)
tree2db35c1e8f9e6da2701b3efc1cc26dbb9aefe369
parenta2ed1ee91f4f2c59b71db12c16bff659dee9ee0b (diff)
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ACPI: APEI: Fix possible out-of-bounds access to BERT region
Check that the length recorded in the generic error status block is within the region before checking the contents of the region itself. Otherwise it may result in an out-of-bounds access if the system firmware has generated a status block with an invalid length (larger than the mapped region). Also move the block_status check so that it only happens after the block has been verified to be within the mapped region. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Acked-by: Borislav Petkov <bp@suse.de> Tested-by: Tyler Baicar <baicar.tyler@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--drivers/acpi/apei/bert.c23
1 files changed, 10 insertions, 13 deletions
diff --git a/drivers/acpi/apei/bert.c b/drivers/acpi/apei/bert.c
index 12771fcf0417..0d948d0a41af 100644
--- a/drivers/acpi/apei/bert.c
+++ b/drivers/acpi/apei/bert.c
@@ -42,15 +42,7 @@ static void __init bert_print_all(struct acpi_bert_region *region,
int remain = region_len;
u32 estatus_len;
- if (!estatus->block_status)
- return;
-
- while (remain > sizeof(struct acpi_bert_region)) {
- if (cper_estatus_check(estatus)) {
- pr_err(FW_BUG "Invalid error record.\n");
- return;
- }
-
+ while (remain >= sizeof(struct acpi_bert_region)) {
estatus_len = cper_estatus_len(estatus);
if (remain < estatus_len) {
pr_err(FW_BUG "Truncated status block (length: %u).\n",
@@ -58,6 +50,15 @@ static void __init bert_print_all(struct acpi_bert_region *region,
return;
}
+ /* No more error records. */
+ if (!estatus->block_status)
+ return;
+
+ if (cper_estatus_check(estatus)) {
+ pr_err(FW_BUG "Invalid error record.\n");
+ return;
+ }
+
pr_info_once("Error records from previous boot:\n");
cper_estatus_print(KERN_INFO HW_ERR, estatus);
@@ -70,10 +71,6 @@ static void __init bert_print_all(struct acpi_bert_region *region,
estatus->block_status = 0;
estatus = (void *)estatus + estatus_len;
- /* No more error records. */
- if (!estatus->block_status)
- return;
-
remain -= estatus_len;
}
}