From af6281ee2cf518e8fa8a14c7c74133c4ff4c6676 Mon Sep 17 00:00:00 2001
From: Len Baker <len.baker@gmx.com>
Date: Sat, 4 Sep 2021 17:41:06 +0200
Subject: drm/radeon: Prefer kcalloc over open coded arithmetic
Git-commit: 67684fcbdd0ef60a52f15e74e0e8a85edc867ce4
Patch-mainline: v5.16-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.
So, refactor the code a bit to use the purpose specific kcalloc()
function instead of the calculated size argument in the kzalloc()
function.
[1] https://www.kernel.org/doc/html/v5.14/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
Signed-off-by: Len Baker <len.baker@gmx.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/radeon/r600_dpm.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/radeon/r600_dpm.c b/drivers/gpu/drm/radeon/r600_dpm.c
index 35b77c944701..fd4226b99862 100644
--- a/drivers/gpu/drm/radeon/r600_dpm.c
+++ b/drivers/gpu/drm/radeon/r600_dpm.c
@@ -820,12 +820,12 @@ union fan_info {
static int r600_parse_clk_voltage_dep_table(struct radeon_clock_voltage_dependency_table *radeon_table,
ATOM_PPLIB_Clock_Voltage_Dependency_Table *atom_table)
{
- u32 size = atom_table->ucNumEntries *
- sizeof(struct radeon_clock_voltage_dependency_entry);
int i;
ATOM_PPLIB_Clock_Voltage_Dependency_Record *entry;
- radeon_table->entries = kzalloc(size, GFP_KERNEL);
+ radeon_table->entries = kcalloc(atom_table->ucNumEntries,
+ sizeof(struct radeon_clock_voltage_dependency_entry),
+ GFP_KERNEL);
if (!radeon_table->entries)
return -ENOMEM;
--
2.38.1