[PATCH 6.18 102/175] io_uring/rw: free potentially allocated iovec on cache put failure

Greg Kroah-Hartman
2026-02-09T14:30:43Z

From: Jens Axboe <axboe@kernel.dk>

[ Upstream commit 4b9748055457ac3a0710bf210c229d01ea1b01b9 ]

If a read/write request goes through io_req_rw_cleanup() and has an
allocated iovec attached and fails to put to the rw_cache, then it may
end up with an unaccounted iovec pointer. Have io_rw_recycle() return
whether it recycled the request or not, and use that to gauge whether to
free a potential iovec or not.

Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
io_uring/rw.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/io_uring/rw.c b/io_uring/rw.c
index abe68ba9c9dc8..d7388a4a3ea5e 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -144,19 +144,22 @@ static inline int io_import_rw_buffer(int rw, struct io_kiocb *req,
return 0;
}

-static void io_rw_recycle(struct io_kiocb *req, unsigned int issue_flags)
+static bool io_rw_recycle(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_async_rw *rw = req->async_data;

if (unlikely(issue_flags & IO_URING_F_UNLOCKED))
- return;
+ return false;

io_alloc_cache_vec_kasan(&rw->vec);
if (rw->vec.nr > IO_VEC_CACHE_SOFT_CAP)
io_vec_free(&rw->vec);

- if (io_alloc_cache_put(&req->ctx->rw_cache, rw))
+ if (io_alloc_cache_put(&req->ctx->rw_cache, rw)) {
io_req_async_data_clear(req, 0);
+ return true;
+ }
+ return false;
}

static void io_req_rw_cleanup(struct io_kiocb *req, unsigned int issue_flags)
@@ -190,7 +193,11 @@ static void io_req_rw_cleanup(struct io_kiocb *req, unsigned int issue_flags)
*/
if (!(req->flags & (REQ_F_REISSUE | REQ_F_REFCOUNT))) {
req->flags &= ~REQ_F_NEED_CLEANUP;
- io_rw_recycle(req, issue_flags);
+ if (!io_rw_recycle(req, issue_flags)) {
+ struct io_async_rw *rw = req->async_data;
+
+ io_vec_free(&rw->vec);
+ }
}
}

--
2.51.0