From 7c30f36a98ae488741178d69662e4f2baa53e7f6 Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Sun, 7 Mar 2021 11:54:28 +0100 Subject: [PATCH] io_uring: run __io_sq_thread() with the initial creds from io_uring_setup() With IORING_SETUP_ATTACH_WQ we should let __io_sq_thread() use the initial creds from each ctx. Signed-off-by: Stefan Metzmacher Signed-off-by: Jens Axboe --- fs/io_uring.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index 8c74c7799960..4d3333ca27a3 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -380,6 +380,7 @@ struct io_ring_ctx { /* Only used for accounting purposes */ struct mm_struct *mm_account; + const struct cred *sq_creds; /* cred used for __io_sq_thread() */ struct io_sq_data *sq_data; /* if using sq thread polling */ struct wait_queue_head sqo_sq_wait; @@ -6719,7 +6720,13 @@ static int io_sq_thread(void *data) sqt_spin = false; cap_entries = !list_is_singular(&sqd->ctx_list); list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { + const struct cred *creds = NULL; + + if (ctx->sq_creds != current_cred()) + creds = override_creds(ctx->sq_creds); ret = __io_sq_thread(ctx, cap_entries); + if (creds) + revert_creds(creds); if (!sqt_spin && (ret > 0 || !list_empty(&ctx->iopoll_list))) sqt_spin = true; } @@ -7152,6 +7159,8 @@ static void io_sq_thread_finish(struct io_ring_ctx *ctx) io_put_sq_data(sqd); ctx->sq_data = NULL; + if (ctx->sq_creds) + put_cred(ctx->sq_creds); } } @@ -7890,6 +7899,7 @@ static int io_sq_offload_create(struct io_ring_ctx *ctx, goto err; } + ctx->sq_creds = get_current_cred(); ctx->sq_data = sqd; io_sq_thread_park(sqd); mutex_lock(&sqd->ctx_lock);