From 75c4021aacbd9b5cc13b173d32b49007fd8ccada Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Thu, 15 Apr 2021 13:07:40 +0100 Subject: io_uring: check register restriction afore quiesce Move restriction checks of __io_uring_register() before quiesce, saves from waiting for requests in fail case and simplifies the code a bit. Also add array_index_nospec() for safety Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/88d7913c9280ee848fdb7b584eea37a465391cee.1618488258.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index bae13811d2f3..e491b815df8c 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -9738,6 +9738,14 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, if (percpu_ref_is_dying(&ctx->refs)) return -ENXIO; + if (ctx->restricted) { + if (opcode >= IORING_REGISTER_LAST) + return -EINVAL; + opcode = array_index_nospec(opcode, IORING_REGISTER_LAST); + if (!test_bit(opcode, ctx->restrictions.register_op)) + return -EACCES; + } + if (io_register_op_must_quiesce(opcode)) { percpu_ref_kill(&ctx->refs); @@ -9766,18 +9774,6 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, } } - if (ctx->restricted) { - if (opcode >= IORING_REGISTER_LAST) { - ret = -EINVAL; - goto out; - } - - if (!test_bit(opcode, ctx->restrictions.register_op)) { - ret = -EACCES; - goto out; - } - } - switch (opcode) { case IORING_REGISTER_BUFFERS: ret = io_sqe_buffers_register(ctx, arg, nr_args); @@ -9851,7 +9847,6 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, break; } -out: if (io_register_op_must_quiesce(opcode)) { /* bring the ctx back to life */ percpu_ref_reinit(&ctx->refs); -- cgit v1.2.3