Some BIOSes report incorrect length for ACPI address space descriptors,
so relax the checks to avoid regressions. This issue has appeared several
times as:
3162b6f0c5e1 ("PNPACPI: truncate _CRS windows with _LEN > _MAX - _MIN + 1")
d558b483d5a7 ("x86/PCI: truncate _CRS windows with _LEN > _MAX - _MIN + 1")
f238b414a74a ("PNPACPI: compute Address Space length rather than using _LEN")
48728e077480 ("x86/PCI: compute Address Space length rather than using _LEN")
Please refer to https://bugzilla.kernel.org/show_bug.cgi?id=94221
for more details and example malformed ACPI resource descriptors.
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
Tested-by: Dave Airlie <airlied@xxxxxxxxxx>
Tested-by: Prakash Punnoor <prakash@xxxxxxxxxx>
---
drivers/acpi/resource.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index c723668e3e27..5589a6e2a023 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -42,8 +42,10 @@ static bool acpi_dev_resource_len_valid(u64 start, u64 end, u64 len, bool io)
* CHECKME: len might be required to check versus a minimum
* length as well. 1 for io is fine, but for memory it does
* not make any sense at all.
+ * Note: some BIOSes report incorrect length for ACPI address space
+ * descriptor, so remove check of 'reslen == len' to avoid regression.
*/
- if (len && reslen && reslen == len && start <= end)
+ if (len && reslen && start <= end)
return true;
pr_debug("ACPI: invalid or unassigned resource %s [%016llx - %016llx] length [%016llx]\n",
--
1.7.10.4
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