Forcing an int to be dereferenced at uint64_t for div64_u64_rem() runs
the risk of endian confusion and stack overflowing writes. Seen while
preparing to enable -Warray-bounds globally:
In file included from ../arch/x86/include/asm/processor.h:35,
from ../include/linux/sched.h:13,
from ../include/linux/ratelimit.h:6,
from ../include/linux/dev_printk.h:16,
from ../drivers/gpu/drm/amd/amdgpu/../ras/ras_mgr/ras_sys.h:29,
from ../drivers/gpu/drm/amd/amdgpu/../ras/rascore/ras.h:27,
from
../drivers/gpu/drm/amd/amdgpu/../ras/rascore/ras_core.c:24:
In function 'div64_u64_rem',
inlined from 'ras_core_convert_timestamp_to_time' at
../drivers/gpu/drm/amd/amdgpu/../ras/rascore/ras_core.c:72:9:
../include/linux/math64.h:56:20: error: array subscript 'u64 {aka long long
unsigned int}[0]' is partly outside array bounds of 'int[1]'
[-Werror=array-bounds=]
56 | *remainder = dividend % divisor;
| ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/amd/amdgpu/../ras/rascore/ras_core.c: In function
'ras_core_convert_timestamp_to_time':
../drivers/gpu/drm/amd/amdgpu/../ras/rascore/ras_core.c:70:19: note: object
'remaining_seconds' of size 4
70 | int days, remaining_seconds;
| ^~~~~~~~~~~~~~~~~
Switch remaining_seconds to uint64_t to avoid the problems.
Fixes: ace232eff50e ("drm/amdgpu: Add ras module files into amdgpu")
Signed-off-by: Kees Cook <[email protected]>
---
Cc: Alex Deucher <[email protected]>
Cc: "Christian König" <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Simona Vetter <[email protected]>
Cc: YiPeng Chai <[email protected]>
Cc: Tao Zhou <[email protected]>
Cc: Hawking Zhang <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
---
drivers/gpu/drm/amd/ras/rascore/ras_core.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/ras/rascore/ras_core.c
b/drivers/gpu/drm/amd/ras/rascore/ras_core.c
index 01122b55c98a..91e16b0b98f9 100644
--- a/drivers/gpu/drm/amd/ras/rascore/ras_core.c
+++ b/drivers/gpu/drm/amd/ras/rascore/ras_core.c
@@ -63,13 +63,14 @@ int ras_core_convert_timestamp_to_time(struct
ras_core_context *ras_core,
{
int days_in_month[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
uint64_t month = 0, day = 0, hour = 0, minute = 0, second = 0;
+ uint64_t remaining_seconds;
uint32_t year = 0;
int seconds_per_day = 24 * 60 * 60;
int seconds_per_hour = 60 * 60;
int seconds_per_minute = 60;
- int days, remaining_seconds;
+ int days;
- days = div64_u64_rem(timestamp, seconds_per_day, (uint64_t
*)&remaining_seconds);
+ days = div64_u64_rem(timestamp, seconds_per_day, &remaining_seconds);
/* utc_timestamp follows the Unix epoch */
year = 1970;
--
2.34.1
