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-ari...
Signed-off-by: Len Baker len.baker@gmx.com --- 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;
-- 2.25.1
Applied. Thanks!
Alex
On Sat, Sep 4, 2021 at 11:41 AM Len Baker len.baker@gmx.com wrote:
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-ari...
Signed-off-by: Len Baker len.baker@gmx.com
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;-- 2.25.1
dri-devel@lists.freedesktop.org
-
Alex Deucher -
Len Baker