From: Michael Guralnik Tracer creation can fail by returning either NULL or ERR_PTR. The return value is stored without a check on the device, and users treat ERR_PTR and NULL the same way. This also causes a crash in the core dump logic, which is missing the ERR_PTR check and ends up dereferencing it, as shown in the trace below. Switch tracer creation to return NULL on failure only, so callers only need a single NULL check. Internal error: Oops: 0000000096000006 [#1] SMP Modules linked in: mlx5_ib ib_uverbs ib_core ipv6 mlx5_core CPU: 1 UID: 0 PID: 12 Comm: kworker/u16:0 Not tainted 6.19.7 #1 PREEMPT(none) Workqueue: mlx5_health0001:01:00.0 mlx5_fw_reporter_err_work [mlx5_core] pstate: a3400009 (NzCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : mlx5_fw_tracer_trigger_core_dump_general+0x58/0xe0 [mlx5_core] lr : mlx5_fw_tracer_trigger_core_dump_general+0x40/0xe0 [mlx5_core] sp : ffff800081cf3c40 x29: ffff800081cf3c90 x28: 0000000000000000 x27: 0000000000000000 x26: ffff000080018828 x25: 0000000000000000 x24: ffff000080304a05 x23: ffff800081cf3d80 x22: ffff0000847e01a0 x21: 0000000000000000 x20: ffff0000847e01a0 x19: ffffffffffffffa1 x18: ffff80008310bbf0 x17: ffff800080119650 x16: ffff80008010df54 x15: ffff80008010d4ac x14: ffff800079c202e4 x13: ffff80008002fe60 x12: ffff800080119650 x11: ffff80008010df54 x10: ffff80008010d4ac x9 : ffff800079c203d8 x8 : ffff800081cf3c88 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000008 x3 : 0000000000000030 x2 : 0000000000000008 x1 : 0000000000000000 x0 : 00000000c5c4000e Call trace: mlx5_fw_tracer_trigger_core_dump_general+0x58/0xe0 [mlx5_core] (P) mlx5_fw_reporter_dump+0x30/0x2e0 [mlx5_core] devlink_health_do_dump+0x9c/0x160 devlink_health_report+0x1c0/0x288 mlx5_fw_reporter_err_work+0xac/0xc0 [mlx5_core] process_one_work+0x15c/0x3d8 worker_thread+0x18c/0x320 kthread+0x148/0x228 ret_from_fork+0x10/0x20 Code: b9400000 5ac00800 7a401800 540003ca (3940a260) ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Oops: Fatal exception SMP: stopping secondary CPUs Kernel Offset: disabled CPU features: 0x000000,00078031,75fce5a1,35fffe67 Memory Limit: none ---[ end Kernel panic - not syncing: Oops: Fatal exception ]--- Fixes: fd1483fe1f9f ("net/mlx5: Add support for FW reporter dump") Signed-off-by: Michael Guralnik Reviewed-by: Shay Drori Signed-off-by: Tariq Toukan --- .../ethernet/mellanox/mlx5/core/diag/fw_tracer.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c b/drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c index adcc73e2a5b3..1493d8106c1a 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c @@ -1025,13 +1025,11 @@ struct mlx5_fw_tracer *mlx5_fw_tracer_create(struct mlx5_core_dev *dev) tracer = kvzalloc_obj(*tracer); if (!tracer) - return ERR_PTR(-ENOMEM); + return NULL; tracer->work_queue = create_singlethread_workqueue("mlx5_fw_tracer"); - if (!tracer->work_queue) { - err = -ENOMEM; + if (!tracer->work_queue) goto free_tracer; - } tracer->dev = dev; @@ -1073,7 +1071,7 @@ struct mlx5_fw_tracer *mlx5_fw_tracer_create(struct mlx5_core_dev *dev) destroy_workqueue(tracer->work_queue); free_tracer: kvfree(tracer); - return ERR_PTR(err); + return NULL; } static int fw_tracer_event(struct notifier_block *nb, unsigned long action, void *data); @@ -1084,7 +1082,7 @@ int mlx5_fw_tracer_init(struct mlx5_fw_tracer *tracer) struct mlx5_core_dev *dev; int err; - if (IS_ERR_OR_NULL(tracer)) + if (!tracer) return 0; if (!tracer->str_db.loaded) @@ -1134,7 +1132,7 @@ int mlx5_fw_tracer_init(struct mlx5_fw_tracer *tracer) /* Stop tracer + Cleanup HW resources */ void mlx5_fw_tracer_cleanup(struct mlx5_fw_tracer *tracer) { - if (IS_ERR_OR_NULL(tracer)) + if (!tracer) return; mutex_lock(&tracer->state_lock); @@ -1163,7 +1161,7 @@ void mlx5_fw_tracer_cleanup(struct mlx5_fw_tracer *tracer) /* Free software resources (Buffers, etc ..) */ void mlx5_fw_tracer_destroy(struct mlx5_fw_tracer *tracer) { - if (IS_ERR_OR_NULL(tracer)) + if (!tracer) return; mlx5_core_dbg(tracer->dev, "FWTracer: Destroy\n"); @@ -1215,7 +1213,7 @@ int mlx5_fw_tracer_reload(struct mlx5_fw_tracer *tracer) struct mlx5_core_dev *dev; int err; - if (IS_ERR_OR_NULL(tracer)) + if (!tracer) return 0; dev = tracer->dev; base-commit: 3bd438a58e910db5dc369aa25dfed1fc95f1b596 -- 2.44.0