net/mlx5e: Do not use ptp structure for tx ts stats when not initialized

Binary-Eater · NipaLocal · commit 5a64e1f43984 · 2024-05-22T23:00:26.000-07:00
The ptp channel instance is only initialized when ptp traffic is first processed by the driver. This means that there is a window in between when port timestamping is enabled and ptp traffic is sent where the ptp channel instance is not initialized. Accessing statistics during this window will lead to an access violation (NULL + member offset). Check the validity of the instance before attempting to query statistics. BUG: unable to handle page fault for address: 0000000000003524 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 109dfc067 P4D 109dfc067 PUD 1064ef067 PMD 0 Oops: 0000 [#1] SMP CPU: 0 PID: 420 Comm: ethtool Not tainted 6.9.0-rc2-rrameshbabu+ torvalds#245 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Arch Linux 1.16.3-1-1 04/01/204 RIP: 0010:mlx5e_stats_ts_get+0x4c/0x130 <snip> Call Trace: <TASK> ? show_regs+0x60/0x70 ? __die+0x24/0x70 ? page_fault_oops+0x15f/0x430 ? do_user_addr_fault+0x2c9/0x5c0 ? exc_page_fault+0x63/0x110 ? asm_exc_page_fault+0x27/0x30 ? mlx5e_stats_ts_get+0x4c/0x130 ? mlx5e_stats_ts_get+0x20/0x130 mlx5e_get_ts_stats+0x15/0x20 <snip> Fixes: 3579032 ("net/mlx5e: Implement ethtool hardware timestamping statistics") Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com> Signed-off-by: Tariq Toukan <tariqt@nvidia.com> Signed-off-by: NipaLocal <nipa@local>
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
@@ -1186,6 +1186,9 @@ void mlx5e_stats_ts_get(struct mlx5e_priv *priv,
 		ts_stats->err = 0;
 		ts_stats->lost = 0;
 
+		if (!ptp)
+			goto out;
+
 		/* Aggregate stats across all TCs */
 		for (i = 0; i < ptp->num_tc; i++) {
 			struct mlx5e_ptp_cq_stats *stats =
@@ -1214,6 +1217,7 @@ void mlx5e_stats_ts_get(struct mlx5e_priv *priv,
 		}
 	}
 
+out:
 	mutex_unlock(&priv->state_lock);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -1186,6 +1186,9 @@ void mlx5e_stats_ts_get(struct mlx5e_priv *priv,`
`1186`	`1186`	`ts_stats->err = 0;`
`1187`	`1187`	`ts_stats->lost = 0;`
`1188`	`1188`
	`1189`	`+ if (!ptp)`
	`1190`	`+ goto out;`
	`1191`	`+`
`1189`	`1192`	`/* Aggregate stats across all TCs */`
`1190`	`1193`	`for (i = 0; i < ptp->num_tc; i++) {`
`1191`	`1194`	`struct mlx5e_ptp_cq_stats *stats =`
`@@ -1214,6 +1217,7 @@ void mlx5e_stats_ts_get(struct mlx5e_priv *priv,`
`1214`	`1217`	`}`
`1215`	`1218`	`}`
`1216`	`1219`
	`1220`	`+out:`
`1217`	`1221`	`mutex_unlock(&priv->state_lock);`
`1218`	`1222`	`}`
`1219`	`1223`