linux-stable/io_uring/cancel.h
Pavel Begunkov f4a1254f2a io_uring: fix cancellation overwriting req->flags
Only the current owner of a request is allowed to write into req->flags.
Hence, the cancellation path should never touch it. Add a new field
instead of the flag, move it into the 3rd cache line because it should
always be initialised. poll_refs can move further as polling is an
involved process anyway.

It's a minimal patch, in the future we can and should find a better
place for it and remove now unused REQ_F_CANCEL_SEQ.

Fixes: 521223d7c2 ("io_uring/cancel: don't default to setting req->work.cancel_seq")
Cc: stable@vger.kernel.org
Reported-by: Li Shi <sl1589472800@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6827b129f8f0ad76fa9d1f0a773de938b240ffab.1718323430.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-13 19:25:28 -06:00

38 lines
962 B
C

// SPDX-License-Identifier: GPL-2.0
#ifndef IORING_CANCEL_H
#define IORING_CANCEL_H
#include <linux/io_uring_types.h>
struct io_cancel_data {
struct io_ring_ctx *ctx;
union {
u64 data;
struct file *file;
};
u8 opcode;
u32 flags;
int seq;
};
int io_async_cancel_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags);
int io_try_cancel(struct io_uring_task *tctx, struct io_cancel_data *cd,
unsigned int issue_flags);
void init_hash_table(struct io_hash_table *table, unsigned size);
int io_sync_cancel(struct io_ring_ctx *ctx, void __user *arg);
bool io_cancel_req_match(struct io_kiocb *req, struct io_cancel_data *cd);
static inline bool io_cancel_match_sequence(struct io_kiocb *req, int sequence)
{
if (req->cancel_seq_set && sequence == req->work.cancel_seq)
return true;
req->cancel_seq_set = true;
req->work.cancel_seq = sequence;
return false;
}
#endif