[PATCH AUTOSEL 6.1 07/10] io_uring: check for valid register opcode earlier

Sasha Levin
2023-01-03T18:40:22Z

From: Jens Axboe <axboe@kernel.dk>

[ Upstream commit 343190841a1f22b96996d9f8cfab902a4d1bfd0e ]

We only check the register opcode value inside the restricted ring
section, move it into the main io_uring_register() function instead
and check it up front.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
io_uring/io_uring.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 17771cb3c333..01528a919751 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -3897,8 +3897,6 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
return -EEXIST;

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;
@@ -4054,6 +4052,9 @@ SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
long ret = -EBADF;
struct fd f;

+ if (opcode >= IORING_REGISTER_LAST)
+ return -EINVAL;
+
f = fdget(fd);
if (!f.file)
return -EBADF;
--
2.35.1