diff options
| author | Jens Axboe <axboe@kernel.dk> | 2026-03-12 17:59:25 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-03-25 13:06:02 +0300 |
| commit | 439a6728ec4641ffad1ca796622c19bc525e570f (patch) | |
| tree | 8ee65af8a06a9d2473a214feaca061b8f16a7503 /io_uring/kbuf.c | |
| parent | d77401968c789037b1ba962705ef998133715b1f (diff) | |
| download | linux-439a6728ec4641ffad1ca796622c19bc525e570f.tar.xz | |
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/kbuf.c')
| -rw-r--r-- | io_uring/kbuf.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index b2c381634393..ad1e14359662 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -70,9 +70,15 @@ void 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); + /* + * 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->is_mapped) + list_add(&buf->list, &bl->buf_list); req->flags &= ~REQ_F_BUFFER_SELECTED; req->buf_index = buf->bgid; + req->kbuf = NULL; io_ring_submit_unlock(ctx, issue_flags); return; |