commit 3d8f874bd6 upstream.
The NOP op flags should have been checked from beginning like any other
opcode, otherwise NOP may not be extended with the op flags.
Given both liburing and Rust io-uring crate always zeros SQE op flags, just
ignore users which play raw NOP uring interface without zeroing SQE, because
NOP is just for test purpose. Then we can save one NOP2 opcode.
Suggested-by: Jens Axboe <axboe@kernel.dk>
Fixes: 2b188cc1bb ("Add io_uring IO interface")
Cc: stable@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20240510035031.78874-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 6e5e6d2749 upstream.
This is dead code after we dropped support for passing io_uring fds
over SCM_RIGHTS, get rid of it.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Commit a4104821ad upstream.
Since we no longer allow sending io_uring fds over SCM_RIGHTS, move to
using io_is_uring_fops() to detect whether this is a io_uring fd or not.
With that done, kill off io_uring_get_socket() as nobody calls it
anymore.
This is in preparation to yanking out the rest of the core related to
unix gc with io_uring.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 705318a99a upstream.
File reference cycles have caused lots of problems for io_uring
in the past, and it still doesn't work exactly right and races with
unix_stream_read_generic(). The safest fix would be to completely
disallow sending io_uring files via sockets via SCM_RIGHT, so there
are no possible cycles invloving registered files and thus rendering
SCM accounting on the io_uring side unnecessary.
Cc: <stable@vger.kernel.org>
Fixes: 0091bfc817 ("io_uring/af_unix: defer registered files gc to io_uring release")
Reported-and-suggested-by: Jann Horn <jannh@google.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c716c88321939156909cfa1bd8b0faaf1c804103.1701868795.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d6fef34ee4 upstream.
If the offset equals the bv_len of the first registered bvec, then the
request does not include any of that first bvec. Skip it so that drivers
don't have to deal with a zero length bvec, which was observed to break
NVMe's PRP list creation.
Cc: stable@vger.kernel.org
Fixes: bd11b3a391 ("io_uring: don't use iov_iter_advance() for fixed buffers")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20231120221831.2646460-1-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No upstream commit exists for this patch.
Don't free the request unconditionally, if the request is issued async
then someone else may be holding a submit reference to it.
Reported-and-tested-by: Lee Jones <lee@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No upstream commit exists for this patch.
If we drop the lock right after adding it to the timeout list, then
someone attempting to kill timeouts will find it in an indeterminate
state. That means that cancelation could attempt to cancel and remove
a timeout, and then io_timeout() proceeds to init and add the timer
afterwards.
Ensure the timeout request is fully setup before we drop the
completion lock, which guards cancelation as well.
Reported-and-tested-by: Lee Jones <lee@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No upstream commit exists for this patch.
It's not necessarily safe to check the task_list locklessly, remove
this micro optimization and always grab task_lock before deeming it
empty.
Reported-and-tested-by: Lee Jones <lee@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ upstream commit 0091bfc817 ]
Instead of putting io_uring's registered files in unix_gc() we want it
to be done by io_uring itself. The trick here is to consider io_uring
registered files for cycle detection but not actually putting them down.
Because io_uring can't register other ring instances, this will remove
all refs to the ring file triggering the ->release path and clean up
with io_ring_ctx_free().
Cc: stable@vger.kernel.org
Fixes: 6b06314c47 ("io_uring: add file set registration")
Reported-and-tested-by: David Bouman <dbouman03@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
[axboe: add kerneldoc comment to skb, fold in skb leak fix]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Older kernels lack io_uring POLLFREE handling. As only affected files
are signalfd and android binder the safest option would be to disable
polling those files via io_uring and hope there are no users.
Fixes: 221c5eb233 ("io_uring: add support for IORING_OP_POLL")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is a bunch of cases where we can grab req->fs but not put it, this
can be used to cause a controllable overflow with further implications.
Release req->fs in the request free path and make sure we zero the field
to be sure we don't do it twice.
Fixes: cac68d12c5 ("io_uring: grab ->fs as part of async offload")
Reported-by: Bing-Jhong Billy Jheng <billy@starlabs.sg>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No upstream commit, this is a fix to a stable 5.4 specific backport.
The intention of backport commit cac68d12c5 ("io_uring: grab ->fs as part
of async offload") as found in the stable 5.4 tree was to make
io_sq_wq_submit_work() to switch the workqueue task's ->fs over to the
submitting task's one during the IO operation.
However, due to a small logic error, this change turned out to not have any
actual effect. From a high level, the relevant code in
io_sq_wq_submit_work() looks like
old_fs_struct = current->fs;
do {
...
if (req->fs != current->fs && current->fs != old_fs_struct) {
task_lock(current);
if (req->fs)
current->fs = req->fs;
else
current->fs = old_fs_struct;
task_unlock(current);
}
...
} while (req);
The if condition is supposed to cover the case that current->fs doesn't
match what's needed for processing the request, but observe how it fails
to ever evaluate to true due to the second clause:
current->fs != old_fs_struct will be false in the first iteration as per
the initialization of old_fs_struct and because this prevents current->fs
from getting replaced, the same follows inductively for all subsequent
iterations.
Fix said if condition such that
- if req->fs is set and doesn't match current->fs, the latter will be
switched to the former
- or if req->fs is unset, the switch back to the initial old_fs_struct
will be made, if necessary.
While at it, also correct the condition for the ->fs related cleanup right
before the return of io_sq_wq_submit_work(): currently, old_fs_struct is
restored only if it's non-NULL. It is always non-NULL though and thus, the
if-condition is rendundant. Supposedly, the motivation had been to optimize
and avoid switching current->fs back to the initial old_fs_struct in case
it is found to have the desired value already. Make it so.
Cc: stable@vger.kernel.org # v5.4
Fixes: cac68d12c5 ("io_uring: grab ->fs as part of async offload")
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If we queue work in io_poll_wake(), it will leads to list double
add. So we should add the list when the callback func is the
io_sq_wq_submit_work.
The following oops was seen:
list_add double add: new=ffff9ca6a8f1b0e0, prev=ffff9ca62001cee8,
next=ffff9ca6a8f1b0e0.
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:31!
Call Trace:
<IRQ>
io_poll_wake+0xf3/0x230
__wake_up_common+0x91/0x170
__wake_up_common_lock+0x7a/0xc0
io_commit_cqring+0xea/0x280
? blkcg_iolatency_done_bio+0x2b/0x610
io_cqring_add_event+0x3e/0x60
io_complete_rw+0x58/0x80
dio_complete+0x106/0x250
blk_update_request+0xa0/0x3b0
blk_mq_end_request+0x1a/0x110
blk_mq_complete_request+0xd0/0xe0
nvme_irq+0x129/0x270 [nvme]
__handle_irq_event_percpu+0x7b/0x190
handle_irq_event_percpu+0x30/0x80
handle_irq_event+0x3c/0x60
handle_edge_irq+0x91/0x1e0
do_IRQ+0x4d/0xd0
common_interrupt+0xf/0xf
Fixes: 1c4404efcf ("io_uring: make sure async workqueue is canceled on exit")
Reported-by: Jiachen Zhang <zhangjiachen.jaycee@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the process 0 has been initialized io_uring is complete, and
then fork process 1. If process 1 exits and it leads to delete
all reqs from the task_list. If we kill process 0. We will not
send SIGINT signal to the kworker. So we can not remove the req
from the task_list. The io_sq_wq_submit_work() can do that for
us.
Fixes: 1c4404efcf ("io_uring: make sure async workqueue is canceled on exit")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The store to req->flags and load req->work_task should not be
reordering in io_cancel_async_work(). We should make sure that
either we store REQ_F_CANCE flag to req->flags or we see the
req->work_task setted in io_sq_wq_submit_work().
Fixes: 1c4404efcf ("io_uring: make sure async workqueue is canceled on exit")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The commit
1c4404efcf2c0> ("<io_uring: make sure async workqueue is canceled on exit>")
doesn't solve the resource leak problem totally! When kworker is doing a
io task for the io_uring, The process which submitted the io task has
received a SIGKILL signal from the user. Then the io_cancel_async_work
function could have sent a SIGINT signal to the kworker, but the judging
condition is wrong. So it doesn't send a SIGINT signal to the kworker,
then caused the resource leaking problem.
Why the juding condition is wrong? The process is a multi-threaded process,
we call the thread of the process which has submitted the io task Thread1.
So the req->task is the current macro of the Thread1. when all the threads
of the process have done exit procedure, the last thread will call the
io_cancel_async_work, but the last thread may not the Thread1, so the task
is not equal and doesn't send the SIGINT signal. To fix this bug, we alter
the task attribute of the req with struct files_struct. And check the files
instead.
Fixes: 1c4404efcf ("io_uring: make sure async workqueue is canceled on exit")
Signed-off-by: Yinyin Zhu <zhuyinyin@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bd74048108 upstream.
If we hit an earlier error path in io_uring_create(), then we will have
accounted memory, but not set ctx->{sq,cq}_entries yet. Then when the
ring is torn down in error, we use those values to unaccount the memory.
Ensure we set the ctx entries before we're able to hit a potential error
path.
Cc: stable@vger.kernel.org
Reported-by: Tomáš Chaloupka <chalucha@gmail.com>
Tested-by: Tomáš Chaloupka <chalucha@gmail.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b36200f543 ]
rings_size() sets sq_offset to the total size of the rings (the returned
value which is used for memory allocation). This is wrong: sq array should
be located within the rings, not after them. Set sq_offset to where it
should be.
Fixes: 75b28affdd ("io_uring: allocate the two rings together")
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Hristo Venev <hristo@venev.name>
Cc: io-uring@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
the commit <a4d61e66ee4a> ("<io_uring: prevent re-read of sqe->opcode>")
caused another vulnerability. After io_get_req(), the sqe_submit struct
in req is not initialized, but the following code defaults that
req->submit.opcode is available.
Signed-off-by: Liu Yong <pkfxxxing@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
when ctx->sqo_mm is zero, io_sq_wq_submit_work() frees 'req'
without deleting it from 'task_list'. After that, 'req' is
accessed in io_ring_ctx_wait_and_kill() which lead to
a use-after-free.
Signed-off-by: Guoyu Huang <hgy5945@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Liu reports that he can trigger a NULL pointer dereference with
IORING_OP_SENDMSG, by changing the sqe->opcode after we've validated
that the previous opcode didn't need a file and didn't assign one.
Ensure we validate and read the opcode only once.
Reported-by: Liu Yong <pkfxxxing@gmail.com>
Tested-by: Liu Yong <pkfxxxing@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Track async work items that we queue, so we can safely cancel them
if the ring is closed or the process exits. Newer kernels handle
this automatically with io-wq, but the old workqueue based setup needs
a bit of special help to get there.
There's no upstream variant of this, as that would require backporting
all the io-wq changes from 5.5 and on. Hence I made a one-off that
ensures that we don't leak memory if we have async work items that
need active cancelation (like socket IO).
Reported-by: Agarwal, Anchal <anchalag@amazon.com>
Tested-by: Agarwal, Anchal <anchalag@amazon.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit a8c73c1a61 upstream.
Use kvfree() to free the pages and vmas, since they are allocated by
kvmalloc_array() in a loop.
Fixes: d4ef647510 ("io_uring: avoid page allocation warnings")
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200605093203.40087-1-efremov@linux.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4ed734b0d0 upstream.
With the previous fixes for number of files open checking, I added some
debug code to see if we had other spots where we're checking rlimit()
against the async io-wq workers. The only one I found was file size
checking, which we should also honor.
During write and fallocate prep, store the max file size and override
that for the current ask if we're in io-wq worker context.
Cc: stable@vger.kernel.org # 5.1+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c336e992cb upstream.
We already checked this limit when the file was opened, and we keep it
open in the file table. Hence when we added unit_inflight to the count
we want to register, we're doubly accounting these files. This results
in -EMFILE for file registration, if we're at half the limit.
Cc: stable@vger.kernel.org # v5.1+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d876836204 upstream.
We must set MSG_CMSG_COMPAT if we're in compatability mode, otherwise
the iovec import for these commands will not do the right thing and fail
the command with -EINVAL.
Found by running the test suite compiled as 32-bit.
Cc: stable@vger.kernel.org
Fixes: aa1fa28fc7 ("io_uring: add support for recvmsg()")
Fixes: 0fa03c624d ("io_uring: add support for sendmsg()")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commits 9392a27d88 and ff002b3018 ]
Ensure that the async work grabs ->fs from the queueing task if the
punted commands needs to do lookups.
We don't have these two commits in 5.4-stable:
ff002b30189392a27d88
because they don't apply with the rework that was done in how io_uring
handles offload. Since there's no io-wq in 5.4, it doesn't make sense to
do two patches. I'm attaching my port of the two for 5.4-stable, it's
been tested. Please queue it up for the next 5.4-stable, thanks!
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 7143b5ac57 upstream.
This patch drops 'cur_mm' before calling cond_resched(), to prevent
the sq_thread from spinning even when the user process is finished.
Before this patch, if the user process ended without closing the
io_uring fd, the sq_thread continues to spin until the
'sq_thread_idle' timeout ends.
In the worst case where the 'sq_thread_idle' parameter is bigger than
INT_MAX, the sq_thread will spin forever.
Fixes: 6c271ce2f1 ("io_uring: add submission polling")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c7849be9cc upstream.
Since commit a3a0e43fd7 ("io_uring: don't enter poll loop if we have
CQEs pending"), if we already events pending, we won't enter poll loop.
In case SETUP_IOPOLL and SETUP_SQPOLL are both enabled, if app has
been terminated and don't reap pending events which are already in cq
ring, and there are some reqs in poll_list, io_sq_thread will enter
__io_iopoll_check(), and find pending events, then return, this loop
will never have a chance to exit.
I have seen this issue in fio stress tests, to fix this issue, let
io_sq_thread call io_iopoll_getevents() with argument 'min' being zero,
and remove __io_iopoll_check().
Fixes: a3a0e43fd7 ("io_uring: don't enter poll loop if we have CQEs pending")
Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 73e08e711d upstream.
This ends up being too restrictive for tasks that willingly fork and
share the ring between forks. Andres reports that this breaks his
postgresql work. Since we're close to 5.5 release, revert this change
for now.
Cc: stable@vger.kernel.org
Fixes: 44d282796f ("io_uring: only allow submit from owning task")
Reported-by: Andres Freund <andres@anarazel.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 44d282796f upstream.
If the credentials or the mm doesn't match, don't allow the task to
submit anything on behalf of this ring. The task that owns the ring can
pass the file descriptor to another task, but we don't want to allow
that task to submit an SQE that then assumes the ring mm and creds if
it needs to go async.
Cc: stable@vger.kernel.org
Suggested-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 7c504e6520 ]
There is no reliable way to submit and wait in a single syscall, as
io_submit_sqes() may under-consume sqes (in case of an early error).
Then it will wait for not-yet-submitted requests, deadlocking the user
in most cases.
Don't wait/poll if can't submit all sqes
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit eb065d301e ]
We currently rely on the ring destroy on cleaning things up in case of
failure, but io_allocate_scq_urings() can leave things half initialized
if only parts of it fails.
Be nice and return with either everything setup in success, or return an
error with things nicely cleaned up.
Reported-by: syzbot+0d818c0d39399188f393@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
There's an issue with deferred requests through drain, where if we do
need to defer, we're not copying over the sqe_submit state correctly.
This can result in using uninitialized data when we then later go and
submit the deferred request, like this check in __io_submit_sqe():
if (unlikely(s->index >= ctx->sq_entries))
return -EINVAL;
with 's' being uninitialized, we can randomly fail this check. Fix this
by copying sqe_submit state when we defer a request.
Because it was fixed as part of a cleanup series in mainline, before
anyone realized we had this issue. That removed the separate states
of ->index vs ->submit.sqe. That series is not something I was
comfortable putting into stable, hence the much simpler addition.
Here's the patch in the series that fixes the same issue:
commit cf6fd4bd55
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Mon Nov 25 23:14:39 2019 +0300
io_uring: inline struct sqe_submit
Reported-by: Andres Freund <andres@anarazel.de>
Reported-by: Tomáš Chaloupka
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit aa4c396775 upstream.
Christophe reports that current master fails building on powerpc with
this error:
CC fs/io_uring.o
fs/io_uring.c: In function ‘loop_rw_iter’:
fs/io_uring.c:1628:21: error: implicit declaration of function ‘kmap’
[-Werror=implicit-function-declaration]
iovec.iov_base = kmap(iter->bvec->bv_page)
^
fs/io_uring.c:1628:19: warning: assignment makes pointer from integer
without a cast [-Wint-conversion]
iovec.iov_base = kmap(iter->bvec->bv_page)
^
fs/io_uring.c:1643:4: error: implicit declaration of function ‘kunmap’
[-Werror=implicit-function-declaration]
kunmap(iter->bvec->bv_page);
^
which is caused by a missing highmem.h include. Fix it by including
it.
Fixes: 311ae9e159 ("io_uring: fix dead-hung for non-iter fixed rw")
Reported-by: Christophe Leroy <christophe.leroy@c-s.fr>
Tested-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 441cdbd544 upstream.
We should never return -ERESTARTSYS to userspace, transform it into
-EINTR.
Cc: stable@vger.kernel.org # v5.3+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 311ae9e159 upstream.
Read/write requests to devices without implemented read/write_iter
using fixed buffers can cause general protection fault, which totally
hangs a machine.
io_import_fixed() initialises iov_iter with bvec, but loop_rw_iter()
accesses it as iovec, dereferencing random address.
kmap() page by page in this case
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A test case was reported where two linked reads with registered buffers
failed the second link always. This is because we set the expected value
of a request in req->result, and if we don't get this result, then we
fail the dependent links. For some reason the registered buffer import
returned -ERROR/0, while the normal import returns -ERROR/length. This
broke linked commands with registered buffers.
Fix this by making io_import_fixed() correctly return the mapped length.
Cc: stable@vger.kernel.org # v5.3
Reported-by: 李通洲 <carter.li@eoitek.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For timeout requests io_uring tries to grab a file with specified fd,
which is usually stdin/fd=0.
Update io_op_needs_file()
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently we make sequence == 0 be the same as sequence == 1, but that's
not super useful if the intent is really to have a timeout that's just
a pure timeout.
If the user passes in sqe->off == 0, then don't apply any sequence logic
to the request, let it purely be driven by the timeout specified.
Reported-by: 李通洲 <carter.li@eoitek.com>
Reviewed-by: 李通洲 <carter.li@eoitek.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We use io_kiocb->result == -EAGAIN as a way to know if we need to
re-submit a polled request, as -EAGAIN reporting happens out-of-line
for IO submission failures. This field is cleared when we originally
allocate the request, but it isn't reset when we retry the submission
from async context. This can cause issues where we think something
needs a re-issue, but we're really just reading stale data.
Reset ->result whenever we re-prep a request for polled submission.
Cc: stable@vger.kernel.org
Fixes: 9e645e1105 ("io_uring: add support for sqe links")
Reported-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
syzkaller reported an issue where it looks like a malicious app can
trigger a use-after-free of reading the ctx ->sq_array and ->rings
value right after having installed the ring fd in the process file
table.
Defer ring fd installation until after we're done reading those
values.
Fixes: 75b28affdd ("io_uring: allocate the two rings together")
Reported-by: syzbot+6f03d895a6cd0d06187f@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_queue_link_head() owns shadow_req after taking it as an argument.
By not freeing it in case of an error, it can leak the request along
with taken ctx->refs.
Reviewed-by: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We currently assume that submissions from the sqthread are successful,
and if IO polling is enabled, we use that value for knowing how many
completions to look for. But if we overflowed the CQ ring or some
requests simply got errored and already completed, they won't be
available for polling.
For the case of IO polling and SQTHREAD usage, look at the pending
poll list. If it ever hits empty then we know that we don't have
anymore pollable requests inflight. For that case, simply reset
the inflight count to zero.
Reported-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We currently use the ring values directly, but that can lead to issues
if the application is malicious and changes these values on our behalf.
Created in-kernel cached versions of them, and just overwrite the user
side when we update them. This is similar to how we treat the sq/cq
ring tail/head updates.
Reported-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
