The new GCC 15 warning -Wunterminated-string-initialization reports:
In file included from drivers/net/ethernet/mellanox/mlx5/core/en.h:55,
from drivers/net/ethernet/mellanox/mlx5/core/en_stats.c:34:
drivers/net/ethernet/mellanox/mlx5/core/en_stats.h:57:46: warning:
initializer-string for array of 'char' truncates NUL terminator but destination
lacks 'nonstring' attribute (33 chars into 32 available)
[-Wunterminated-string-initialization]
57 | #define MLX5E_DECLARE_PTP_RQ_STAT(type, fld) "ptp_rq%d_"#fld,
offsetof(type, fld)
| ^~~~~~~~~~~
drivers/net/ethernet/mellanox/mlx5/core/en_stats.c:2279:11: note: in expansion
of macro 'MLX5E_DECLARE_PTP_RQ_STAT'
2279 | { MLX5E_DECLARE_PTP_RQ_STAT(struct mlx5e_rq_stats,
csum_complete_tail_slow) },
| ^~~~~~~~~~~~~~~~~~~~~~~~~
This stat string is being used in ethtool_sprintf(), so it must be a
valid NUL-terminated string. Currently the string lacks the final NUL
byte (as GCC warns), but by absolute luck, the next byte in memory is a
space (decimal 32) followed by a NUL. "format" is immediately followed
by little-endian size_t:
struct counter_desc {
char format[32]; /* 0 32 */
size_t offset; /* 32 8 */
};
The "offset" member is populated by the stats member offset:
#define MLX5E_DECLARE_PTP_RQ_STAT(type, fld) "ptp_rq%d_"#fld, offsetof(type,
fld)
which for this struct mlx5e_rq_stats member, csum_complete_tail_slow, is
32, or space, and then the rest of the "offset" bytes are NULs.
struct mlx5e_rq_stats {
...
u64 csum_complete_tail_slow; /* 32 8 */
The use of vsnprintf(), within ethtool_sprintf(), reads past the end of
"format" and sees the format string as "ptp_rq%d_csum_complete_tail_slow ",
with %d getting resolved by MLX5E_PTP_CHANNEL_IX (value 0):
ethtool_sprintf(data, ptp_rq_stats_desc[i].format,
MLX5E_PTP_CHANNEL_IX);
With an output result of "ptp_rq0_csum_complete_tail_slow", which gets
precisely truncated to 31 characters with a trailing NUL.
So, instead of accidentally getting this correct due to the NUL bytes
at the end of the size_t that happens to follow the format string, just
make the string initializer 1 byte shorter by replacing "%d" with "0",
since MLX5E_PTP_CHANNEL_IX is already hard-coded. This results in no
initializer truncation and no need to call sprintf().
Signed-off-by: Kees Cook <[email protected]>
---
Cc: Saeed Mahameed <[email protected]>
Cc: Tariq Toukan <[email protected]>
Cc: Leon Romanovsky <[email protected]>
Cc: Andrew Lunn <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: Richard Cochran <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
drivers/net/ethernet/mellanox/mlx5/core/en_stats.c | 3 +--
drivers/net/ethernet/mellanox/mlx5/core/en_stats.h | 2 +-
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
index 1c121b435016..19664fa7f217 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
@@ -2424,8 +2424,7 @@ static MLX5E_DECLARE_STATS_GRP_OP_FILL_STRS(ptp)
}
if (priv->rx_ptp_opened) {
for (i = 0; i < NUM_PTP_RQ_STATS; i++)
- ethtool_sprintf(data, ptp_rq_stats_desc[i].format,
- MLX5E_PTP_CHANNEL_IX);
+ ethtool_puts(data, ptp_rq_stats_desc[i].format);
}
}
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
index 8de6fcbd3a03..def5dea1463d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
@@ -54,7 +54,7 @@
#define MLX5E_DECLARE_PTP_TX_STAT(type, fld) "ptp_tx%d_"#fld, offsetof(type,
fld)
#define MLX5E_DECLARE_PTP_CH_STAT(type, fld) "ptp_ch_"#fld, offsetof(type, fld)
#define MLX5E_DECLARE_PTP_CQ_STAT(type, fld) "ptp_cq%d_"#fld, offsetof(type,
fld)
-#define MLX5E_DECLARE_PTP_RQ_STAT(type, fld) "ptp_rq%d_"#fld, offsetof(type,
fld)
+#define MLX5E_DECLARE_PTP_RQ_STAT(type, fld) "ptp_rq0_"#fld, offsetof(type,
fld)
#define MLX5E_DECLARE_QOS_TX_STAT(type, fld) "qos_tx%d_"#fld, offsetof(type,
fld)
--
2.34.1
