From 7d260c5d2d89eb2c8c528d54b576b3aae3e20231 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Wed, 13 May 2026 12:22:26 +0100 Subject: [PATCH] net/mlx5e: Fix use-after-free in mlx5e_tx_reporter_timeout_recover mlx5e_tx_reporter_timeout_recover() accesses sq->netdev after mlx5e_safe_reopen_channels() has torn down and freed the channel (and its embedded SQs). Replace the three sq->netdev references with priv->netdev which is safe because priv outlives channel teardown. The netdev_err() call already used priv->netdev for this reason; make the trylock/unlock and health_channel_eq_recover calls consistent. This fixes the following KASAN splat: BUG: KASAN: use-after-free in mlx5e_tx_reporter_timeout_recover+0x1dd/0x360 [mlx5_core] Read of size 8 at addr ffff889860ed0b28 by task kworker/u113:2/5277 Call Trace: mlx5e_tx_reporter_timeout_recover+0x1dd/0x360 [mlx5_core] devlink_health_reporter_recover+0xa2/0x150 devlink_health_report+0x254/0x7c0 mlx5e_reporter_tx_timeout+0x297/0x380 [mlx5_core] mlx5e_tx_timeout_work+0x109/0x170 [mlx5_core] process_one_work+0x677/0xf20 worker_thread+0x51f/0xd90 kthread+0x3a5/0x810 ret_from_fork+0x208/0x400 ret_from_fork_asm+0x1a/0x30 Fixes: 83ac0304a2d7 ("net/mlx5e: Fix deadlocks between devlink and netdev instance locks") Cc: stable@vger.kernel.org Reviewed-by: Cosmin Ratiu Reviewed-by: Tariq Toukan Signed-off-by: Matt Fleming Link: https://patch.msgid.link/20260513112226.140512-1-matt@readmodwrite.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/mellanox/mlx5/core/en/reporter_tx.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/reporter_tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en/reporter_tx.c index afdeb1b3d425..8409ae73768f 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/reporter_tx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/reporter_tx.c @@ -160,13 +160,13 @@ static int mlx5e_tx_reporter_timeout_recover(void *ctx) * channels are being closed for other reason and this work is not * relevant anymore. */ - while (!netdev_trylock(sq->netdev)) { + while (!netdev_trylock(priv->netdev)) { if (!test_bit(MLX5E_STATE_CHANNELS_ACTIVE, &priv->state)) return 0; msleep(20); } - err = mlx5e_health_channel_eq_recover(sq->netdev, eq, sq->cq.ch_stats); + err = mlx5e_health_channel_eq_recover(priv->netdev, eq, sq->cq.ch_stats); if (!err) { to_ctx->status = 0; /* this sq recovered */ goto out; @@ -186,7 +186,7 @@ static int mlx5e_tx_reporter_timeout_recover(void *ctx) "mlx5e_safe_reopen_channels failed recovering from a tx_timeout, err(%d).\n", err); out: - netdev_unlock(sq->netdev); + netdev_unlock(priv->netdev); return err; }