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| author |   Jens Axboe <axboe@kernel.dk> | 2019-12-18 12:19:41 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-12-18 12:19:41 -0700 |
| commit | fd6c2e4c063d64511657ad0031a1677b6a914859 (patch) | |
| tree | 7430a804ec01e1495d291353ad398b272e45d9cb /fs | |
| parent | io_uring: don't wait when under-submitting (diff) | |
| download | linux-dev-fd6c2e4c063d64511657ad0031a1677b6a914859.tar.xz linux-dev-fd6c2e4c063d64511657ad0031a1677b6a914859.zip | |
io_uring: io_wq_submit_work() should not touch req->rw
I've been chasing a weird and obscure crash that was userspace stack
corruption, and finally narrowed it down to a bit flip that made a
stack address invalid. io_wq_submit_work() unconditionally flips
the req->rw.ki_flags IOCB_NOWAIT bit, but since it's a generic work
handler, this isn't valid. Normal read/write operations own that
part of the request, on other types it could be something else.
Move the IOCB_NOWAIT clear to the read/write handlers where it belongs.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/io_uring.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 81e7fe6dee18..6f084e3cf835 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1817,6 +1817,10 @@ static int io_read(struct io_kiocb *req, struct io_kiocb **nxt, return ret; } + /* Ensure we clear previously set non-block flag */ + if (!force_nonblock) + req->rw.ki_flags &= ~IOCB_NOWAIT; + file = req->file; io_size = ret; if (req->flags & REQ_F_LINK) @@ -1906,6 +1910,10 @@ static int io_write(struct io_kiocb *req, struct io_kiocb **nxt, return ret; } + /* Ensure we clear previously set non-block flag */ + if (!force_nonblock) + req->rw.ki_flags &= ~IOCB_NOWAIT; + file = kiocb->ki_filp; io_size = ret; if (req->flags & REQ_F_LINK) @@ -3274,9 +3282,6 @@ static void io_wq_submit_work(struct io_wq_work **workptr) struct io_kiocb *nxt = NULL; int ret = 0; - /* Ensure we clear previously set non-block flag */ - req->rw.ki_flags &= ~IOCB_NOWAIT; - if (work->flags & IO_WQ_WORK_CANCEL) ret = -ECANCELED; |