From: Jens Axboe axboe@kernel.dk
[ Upstream commit 02a13674fa0e8dd326de8b9f4514b41b03d99003 ]
We need to actively cancel anything that introduces a potential circular loop, where io_uring holds a reference to itself. If the file in question is an io_uring file, then add the request to the inflight list.
Cc: stable@vger.kernel.org # 5.9+ Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Pavel Begunkov asml.silence@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/io_uring.c | 32 ++++++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 8 deletions(-)
--- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1000,6 +1000,9 @@ static inline void io_clean_op(struct io static inline bool __io_match_files(struct io_kiocb *req, struct files_struct *files) { + if (req->file && req->file->f_op == &io_uring_fops) + return true; + return ((req->flags & REQ_F_WORK_INITIALIZED) && (req->work.flags & IO_WQ_WORK_FILES)) && req->work.identity->files == files; @@ -1398,11 +1401,14 @@ static bool io_grab_identity(struct io_k return false; atomic_inc(&id->files->count); get_nsproxy(id->nsproxy); - req->flags |= REQ_F_INFLIGHT;
- spin_lock_irq(&ctx->inflight_lock); - list_add(&req->inflight_entry, &ctx->inflight_list); - spin_unlock_irq(&ctx->inflight_lock); + if (!(req->flags & REQ_F_INFLIGHT)) { + req->flags |= REQ_F_INFLIGHT; + + spin_lock_irq(&ctx->inflight_lock); + list_add(&req->inflight_entry, &ctx->inflight_list); + spin_unlock_irq(&ctx->inflight_lock); + } req->work.flags |= IO_WQ_WORK_FILES; } if (!(req->work.flags & IO_WQ_WORK_MM) && @@ -5886,8 +5892,10 @@ static void io_req_drop_files(struct io_ struct io_ring_ctx *ctx = req->ctx; unsigned long flags;
- put_files_struct(req->work.identity->files); - put_nsproxy(req->work.identity->nsproxy); + if (req->work.flags & IO_WQ_WORK_FILES) { + put_files_struct(req->work.identity->files); + put_nsproxy(req->work.identity->nsproxy); + } spin_lock_irqsave(&ctx->inflight_lock, flags); list_del(&req->inflight_entry); spin_unlock_irqrestore(&ctx->inflight_lock, flags); @@ -6159,6 +6167,15 @@ static struct file *io_file_get(struct i file = __io_file_get(state, fd); }
+ if (file && file->f_op == &io_uring_fops) { + io_req_init_async(req); + req->flags |= REQ_F_INFLIGHT; + + spin_lock_irq(&ctx->inflight_lock); + list_add(&req->inflight_entry, &ctx->inflight_list); + spin_unlock_irq(&ctx->inflight_lock); + } + return file; }
@@ -8578,8 +8595,7 @@ static void io_uring_cancel_files(struct
spin_lock_irq(&ctx->inflight_lock); list_for_each_entry(req, &ctx->inflight_list, inflight_entry) { - if (req->task != task || - req->work.identity->files != files) + if (!io_match_task(req, task, files)) continue; found = true; break;