On Wed, Jun 29, 2022 at 11:33:36PM +0100, Pavel Begunkov wrote:
[ upstream commit 05b538c1765f8d14a71ccf5f85258dcbeaf189f7 ]
We can look inside the fixed buffer table only while holding ->uring_lock, however in some cases we don't do the right async prep for IORING_OP_{WRITE,READ}_FIXED ending up with NULL req->imu forcing making an io-wq worker to try to resolve the fixed buffer without proper locking.
Move req->imu setup into early req init paths, i.e. io_prep_rw(), which is called unconditionally for rw requests and under uring_lock.
Fixes: 634d00df5e1cf ("io_uring: add full-fledged dynamic buffers support") Signed-off-by: Pavel Begunkov asml.silence@gmail.com
fs/io_uring.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-)
Both backports now queued up, thanks.
greg k-h