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authorJens Axboe <axboe@kernel.dk>2025-08-21 13:23:21 -0600
committerJens Axboe <axboe@kernel.dk>2025-08-21 13:53:33 -0600
commit508c1314b342b78591f51c4b5dadee31a88335df (patch)
tree0dcab768c97d040f0a748ed717fe66b73b69253f
parent9d83e1f05c98bab5de350bef89177e2be8b34db0 (diff)
io_uring/futex: ensure io_futex_wait() cleans up properly on failure
The io_futex_data is allocated upfront and assigned to the io_kiocb async_data field, but the request isn't marked with REQ_F_ASYNC_DATA at that point. Those two should always go together, as the flag tells io_uring whether the field is valid or not. Additionally, on failure cleanup, the futex handler frees the data but does not clear ->async_data. Clear the data and the flag in the error path as well. Thanks to Trend Micro Zero Day Initiative and particularly ReDress for reporting this. Cc: stable@vger.kernel.org Fixes: 194bb58c6090 ("io_uring: add support for futex wake and wait") Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--io_uring/futex.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/io_uring/futex.c b/io_uring/futex.c
index 692462d50c8c..9113a44984f3 100644
--- a/io_uring/futex.c
+++ b/io_uring/futex.c
@@ -288,6 +288,7 @@ int io_futex_wait(struct io_kiocb *req, unsigned int issue_flags)
goto done_unlock;
}
+ req->flags |= REQ_F_ASYNC_DATA;
req->async_data = ifd;
ifd->q = futex_q_init;
ifd->q.bitset = iof->futex_mask;
@@ -309,6 +310,8 @@ done:
if (ret < 0)
req_set_fail(req);
io_req_set_res(req, ret, 0);
+ req->async_data = NULL;
+ req->flags &= ~REQ_F_ASYNC_DATA;
kfree(ifd);
return IOU_COMPLETE;
}