io_uring/zctx: check chained notif contexts

Send zc only links ubuf_info for requests coming from the same context.
There are some ambiguous syz reports, so let's check the assumption on
notification completion.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/fd527d8638203fe0f1c5ff06ff2e1d8fd68f831b.1755179962.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
pull/1354/merge
Pavel Begunkov 2025-08-14 15:40:57 +01:00 committed by Jens Axboe
parent 92a96b0a22
commit ab3ea6eac5
1 changed files with 5 additions and 0 deletions

View File

@ -14,10 +14,15 @@ static const struct ubuf_info_ops io_ubuf_ops;
static void io_notif_tw_complete(struct io_kiocb *notif, io_tw_token_t tw)
{
struct io_notif_data *nd = io_notif_to_data(notif);
struct io_ring_ctx *ctx = notif->ctx;
lockdep_assert_held(&ctx->uring_lock);
do {
notif = cmd_to_io_kiocb(nd);
if (WARN_ON_ONCE(ctx != notif->ctx))
return;
lockdep_assert(refcount_read(&nd->uarg.refcnt) == 0);
if (unlikely(nd->zc_report) && (nd->zc_copied || !nd->zc_used))