Commit 667e57da authored Jul 10, 2020 by Yang Yingliang Committed by Jens Axboe Jul 10, 2020

io_uring: fix memleak in io_sqe_files_register()



I got a memleak report when doing some fuzz test:

BUG: memory leak
unreferenced object 0x607eeac06e78 (size 8):
  comm "test", pid 295, jiffies 4294735835 (age 31.745s)
  hex dump (first 8 bytes):
    00 00 00 00 00 00 00 00                          ........
  backtrace:
    [<00000000932632e6>] percpu_ref_init+0x2a/0x1b0
    [<0000000092ddb796>] __io_uring_register+0x111d/0x22a0
    [<00000000eadd6c77>] __x64_sys_io_uring_register+0x17b/0x480
    [<00000000591b89a6>] do_syscall_64+0x56/0xa0
    [<00000000864a281d>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Call percpu_ref_exit() on error path to avoid
refcount memleak.

Fixes: 05f3fb3c ("io_uring: avoid ring quiesce for fixed file set unregister and update")
Cc: stable@vger.kernel.org
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent f3bd9dae

fs/io_uring.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -6699,6 +6699,7 @@ static int io_sqe_files_register(struct io_ring_ctx ctx, void __user arg,
		for (i = 0; i < nr_tables; i++)
		kfree(ctx->file_data->table[i].files);

		percpu_ref_exit(&ctx->file_data->refs);
		kfree(ctx->file_data->table);
		kfree(ctx->file_data);
		ctx->file_data = NULL;

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