From 13770a71ed35512cc73c6b350297a797f0b27880 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Mon, 1 Feb 2021 15:23:42 +0300 Subject: [PATCH] io_uring: Fix NULL dereference in error in io_sqe_files_register() If we hit a "goto out_free;" before the "ctx->file_data" pointer has been assigned then it leads to a NULL derefence when we call: free_fixed_rsrc_data(ctx->file_data); We can fix this by moving the assignment earlier. Fixes: 1ad555c6ae6e ("io_uring: create common fixed_rsrc_data allocation routines") Signed-off-by: Dan Carpenter Reviewed-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index a8bf867..6711200 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -7865,6 +7865,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, file_data = alloc_fixed_rsrc_data(ctx); if (!file_data) return -ENOMEM; + ctx->file_data = file_data; nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE); file_data->table = kcalloc(nr_tables, sizeof(*file_data->table), @@ -7874,7 +7875,6 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, if (io_sqe_alloc_file_tables(file_data, nr_tables, nr_args)) goto out_free; - ctx->file_data = file_data; for (i = 0; i < nr_args; i++, ctx->nr_user_files++) { struct fixed_rsrc_table *table; -- 2.7.4