From 5245a6da27ef79f8dba98dad5542ebe56d311837 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sat, 16 Mar 2024 09:51:40 -0600 Subject: [PATCH] io_uring: clear opcode specific data for an early failure [ Upstream commit e21e1c45e1fe2e31732f40256b49c04e76a17cee ] If failure happens before the opcode prep handler is called, ensure that we clear the opcode specific area of the request, which holds data specific to that request type. This prevents errors where opcode handlers either don't get to clear per-request private data since prep isn't even called. Reported-and-tested-by: syzbot+f8e9a371388aa62ecab4@syzkaller.appspotmail.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- io_uring/io_uring.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 415248c1f82c..68f1b6f8699a 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -1978,6 +1978,13 @@ static void io_init_req_drain(struct io_kiocb *req) } } +static __cold int io_init_fail_req(struct io_kiocb *req, int err) +{ + /* ensure per-opcode data is cleared if we fail before prep */ + memset(&req->cmd.data, 0, sizeof(req->cmd.data)); + return err; +} + static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, const struct io_uring_sqe *sqe) __must_hold(&ctx->uring_lock) @@ -1998,29 +2005,29 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, if (unlikely(opcode >= IORING_OP_LAST)) { req->opcode = 0; - return -EINVAL; + return io_init_fail_req(req, -EINVAL); } def = &io_op_defs[opcode]; if (unlikely(sqe_flags & ~SQE_COMMON_FLAGS)) { /* enforce forwards compatibility on users */ if (sqe_flags & ~SQE_VALID_FLAGS) - return -EINVAL; + return io_init_fail_req(req, -EINVAL); if (sqe_flags & IOSQE_BUFFER_SELECT) { if (!def->buffer_select) - return -EOPNOTSUPP; + return io_init_fail_req(req, -EOPNOTSUPP); req->buf_index = READ_ONCE(sqe->buf_group); } if (sqe_flags & IOSQE_CQE_SKIP_SUCCESS) ctx->drain_disabled = true; if (sqe_flags & IOSQE_IO_DRAIN) { if (ctx->drain_disabled) - return -EOPNOTSUPP; + return io_init_fail_req(req, -EOPNOTSUPP); io_init_req_drain(req); } } if (unlikely(ctx->restricted || ctx->drain_active || ctx->drain_next)) { if (ctx->restricted && !io_check_restriction(ctx, req, sqe_flags)) - return -EACCES; + return io_init_fail_req(req, -EACCES); /* knock it to the slow queue path, will be drained there */ if (ctx->drain_active) req->flags |= REQ_F_FORCE_ASYNC; @@ -2033,9 +2040,9 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, } if (!def->ioprio && sqe->ioprio) - return -EINVAL; + return io_init_fail_req(req, -EINVAL); if (!def->iopoll && (ctx->flags & IORING_SETUP_IOPOLL)) - return -EINVAL; + return io_init_fail_req(req, -EINVAL); if (def->needs_file) { struct io_submit_state *state = &ctx->submit_state; @@ -2059,12 +2066,12 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, req->creds = xa_load(&ctx->personalities, personality); if (!req->creds) - return -EINVAL; + return io_init_fail_req(req, -EINVAL); get_cred(req->creds); ret = security_uring_override_creds(req->creds); if (ret) { put_cred(req->creds); - return ret; + return io_init_fail_req(req, ret); } req->flags |= REQ_F_CREDS; }