diff options
| author | Jens Axboe <axboe@kernel.dk> | 2026-03-12 08:59:25 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-03-19 16:08:42 +0100 |
| commit | 50ad880db3013c6fee0ef13781762a39e2e7ef83 (patch) | |
| tree | 864d9812427793e093d75c9bb7df07ad4e38e601 /io_uring | |
| parent | 950bda065b05e6001f71c0a698a638095bedf702 (diff) | |
io_uring/kbuf: check if target buffer list is still legacy on recycle
commit c2c185be5c85d37215397c8e8781abf0a69bec1f upstream.
There's a gap between when the buffer was grabbed and when it
potentially gets recycled, where if the list is empty, someone could've
upgraded it to a ring provided type. This can happen if the request
is forced via io-wq. The legacy recycling is missing checking if the
buffer_list still exists, and if it's of the correct type. Add those
checks.
Cc: stable@vger.kernel.org
Fixes: c7fb19428d67 ("io_uring: add support for ring mapped supplied buffers")
Reported-by: Keenan Dong <keenanat2000@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/kbuf.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index 308ef71bcb28..09b62d3224f1 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -111,9 +111,18 @@ bool io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags) buf = req->kbuf; bl = io_buffer_get_list(ctx, buf->bgid); - list_add(&buf->list, &bl->buf_list); - bl->nbufs++; + /* + * If the buffer list was upgraded to a ring-based one, or removed, + * while the request was in-flight in io-wq, drop it. + */ + if (bl && !(bl->flags & IOBL_BUF_RING)) { + list_add(&buf->list, &bl->buf_list); + bl->nbufs++; + } else { + kfree(buf); + } req->flags &= ~REQ_F_BUFFER_SELECTED; + req->kbuf = NULL; io_ring_submit_unlock(ctx, issue_flags); return true; |