Currently anything that requires kvmalloc_flex() for allocations will
not get re-cached, and hence the cache freeing path is correct in that
it always uses kfree() to free the allocated memory. But this seems a
bit fragile as it's something that could get mix should that situation
change, so switch io_free_imu() and io_alloc_cache_free() to use kvfree
as the desctructor.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For file updates, the node reset isn't capping the value via
array_index_nospec() like the other paths do. Ensure it's all sane and
have the update path do the proper capping as well.
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull io_uring updates from Jens Axboe:
- Add a callback driven main loop for io_uring, and BPF struct_ops
on top to allow implementing custom event loop logic
- Decouple IOPOLL from being a ring-wide all-or-nothing setting,
allowing IOPOLL use cases to also issue certain white listed
non-polled opcodes
- Timeout improvements. Migrate internal timeout storage from
timespec64 to ktime_t for simpler arithmetic and avoid copying of
timespec data
- Zero-copy receive (zcrx) updates:
- Add a device-less mode (ZCRX_REG_NODEV) for testing and
experimentation where data flows through the copy fallback path
- Fix two-step unregistration regression, DMA length calculations,
xarray mark usage, and a potential 32-bit overflow in id
shifting
- Refactoring toward multi-area support: dedicated refill queue
struct, consolidated DMA syncing, netmem array refilling format,
and guard-based locking
- Zero-copy transmit (zctx) cleanup:
- Unify io_send_zc() and io_sendmsg_zc() into a single function
- Add vectorized registered buffer send for IORING_OP_SEND_ZC
- Add separate notification user_data via sqe->addr3 so
notification and completion CQEs can be distinguished without
extra reference counting
- Switch struct io_ring_ctx internal bitfields to explicit flag bits
with atomic-safe accessors, and annotate the known harmless races on
those flags
- Various optimizations caching ctx and other request fields in local
variables to avoid repeated loads, and cleanups for tctx setup, ring
fd registration, and read path early returns
* tag 'for-7.1/io_uring-20260411' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (58 commits)
io_uring: unify getting ctx from passed in file descriptor
io_uring/register: don't get a reference to the registered ring fd
io_uring/tctx: clean up __io_uring_add_tctx_node() error handling
io_uring/tctx: have io_uring_alloc_task_context() return tctx
io_uring/timeout: use 'ctx' consistently
io_uring/rw: clean up __io_read() obsolete comment and early returns
io_uring/zcrx: use correct mmap off constants
io_uring/zcrx: use dma_len for chunk size calculation
io_uring/zcrx: don't clear not allocated niovs
io_uring/zcrx: don't use mark0 for allocating xarray
io_uring: cast id to u64 before shifting in io_allocate_rbuf_ring()
io_uring/zcrx: reject REG_NODEV with large rx_buf_size
io_uring/cancel: validate opcode for IORING_ASYNC_CANCEL_OP
io_uring/rsrc: use io_cache_free() to free node
io_uring/zcrx: rename zcrx [un]register functions
io_uring/zcrx: check ctrl op payload struct sizes
io_uring/zcrx: cache fallback availability in zcrx ctx
io_uring/zcrx: warn on a repeated area append
io_uring/zcrx: consolidate dma syncing
io_uring/zcrx: netmem array as refiling format
...
io_uring_enter() and io_uring_register() end up having duplicated code
for getting a ctx from a passed in file descriptor, for either a
registered ring descriptor or a normal file descriptor. Move the
io_uring_register_get_file() into io_uring.c and name it a bit more
generically, and use it from both callsites rather than have that logic
and handling duplicated.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This isn't necessary and was only done because the register path isn't a
hot path and hence the extra ref/put doesn't matter, and to have the
exit path be able to unconditionally put whatever file was gotten
regardless of the type.
In preparation for sharing this code with the main io_uring_enter(2)
syscall, drop the reference and have the caller conditionally put the
file if it was a normal file descriptor.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull io_uring fixes from Jens Axboe:
- A previous fix in this release covered the case of the rings being
RCU protected during resize, but it missed a few spots. This covers
the rest
- Fix the cBPF filters when COW'ed, introduced in this merge window
- Fix for an attempt to import a zero sized buffer
- Fix for a missing clamp in importing bundle buffers
* tag 'io_uring-7.0-20260403' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
io_uring/bpf_filters: retain COW'ed settings on parse failures
io_uring: protect remaining lockless ctx->rings accesses with RCU
io_uring/rsrc: reject zero-length fixed buffer import
io_uring/net: fix slab-out-of-bounds read in io_bundle_nbufs()
Replace kfree(node) with io_cache_free() in io_buffer_register_bvec()
to match all other error paths that free nodes allocated via
io_rsrc_node_alloc(). The node is allocated through io_cache_alloc()
internally, so it should be returned to the cache via io_cache_free()
for proper object reuse.
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Link: https://patch.msgid.link/20260331104509.7055-1-liu.yun@linux.dev
[axboe: remove fixes tag, it's not a fix, it's a cleanup]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
validate_fixed_range() admits buf_addr at the exact end of the
registered region when len is zero, because the check uses strict
greater-than (buf_end > imu->ubuf + imu->len). io_import_fixed()
then computes offset == imu->len, which causes the bvec skip logic
to advance past the last bio_vec entry and read bv_offset from
out-of-bounds slab memory.
Return early from io_import_fixed() when len is zero. A zero-length
import has no data to transfer and should not walk the bvec array
at all.
BUG: KASAN: slab-out-of-bounds in io_import_reg_buf+0x697/0x7f0
Read of size 4 at addr ffff888002bcc254 by task poc/103
Call Trace:
io_import_reg_buf+0x697/0x7f0
io_write_fixed+0xd9/0x250
__io_issue_sqe+0xad/0x710
io_issue_sqe+0x7d/0x1100
io_submit_sqes+0x86a/0x23c0
__do_sys_io_uring_enter+0xa98/0x1590
Allocated by task 103:
The buggy address is located 12 bytes to the right of
allocated 584-byte region [ffff888002bcc000, ffff888002bcc248)
Fixes: 8622b20f23 ("io_uring: add validate_fixed_range() for validate fixed buffer")
Signed-off-by: Qi Tang <tpluszz77@gmail.com>
Link: https://patch.msgid.link/20260329164936.240871-1-tpluszz77@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bitfields cannot be set and checked atomically, and this makes it more
clear that these are indeed in shared storage and must be checked and
set in a sane fashion. This is in preparation for annotating a few of
the known racy, but harmless, flags checking.
No intended functional changes in this patch.
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This is the exact same thing as the 'alloc_obj()' version, only much
smaller because there are a lot fewer users of the *alloc_flex()
interface.
As with alloc_obj() version, this was done entirely with mindless brute
force, using the same script, except using 'flex' in the pattern rather
than 'objs*'.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Deduplicate io_buffer_validate() calls by moving the checks into
io_sqe_buffer_register(). Now we also don't need special handling in
io_buffer_validate() passing through buffer removal requests. I also
was using it as a cleanup before some other changes.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
I'll need a flag in the registered buffer struct for dmabuf work, and
it'll be more convenient to have a flags field rather than bit fields,
especially for io_mapped_ubuf initialisation.
We might want to add more flags in the future as well. For example, it
might be useful for debugging and potentially optimisations to split out
a flag indicating the shape of the buffer to gate iov_iter_advance()
walks vs bit/mask arithmetics. It can also be combined with the
direction mask field.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull block updates from Jens Axboe:
- Support for batch request processing for ublk, improving the
efficiency of the kernel/ublk server communication. This can yield
nice 7-12% performance improvements
- Support for integrity data for ublk
- Various other ublk improvements and additions, including a ton of
selftests additions and updated
- Move the handling of blk-crypto software fallback from below the
block layer to above it. This reduces the complexity of dealing with
bio splitting
- Series fixing a number of potential deadlocks in blk-mq related to
the queue usage counter and writeback throttling and rq-qos debugfs
handling
- Add an async_depth queue attribute, to resolve a performance
regression that's been around for a qhilw related to the scheduler
depth handling
- Only use task_work for IOPOLL completions on NVMe, if it is necessary
to do so. An earlier fix for an issue resulted in all these
completions being punted to task_work, to guarantee that completions
were only run for a given io_uring ring when it was local to that
ring. With the new changes, we can detect if it's necessary to use
task_work or not, and avoid it if possible.
- rnbd fixes:
- Fix refcount underflow in device unmap path
- Handle PREFLUSH and NOUNMAP flags properly in protocol
- Fix server-side bi_size for special IOs
- Zero response buffer before use
- Fix trace format for flags
- Add .release to rnbd_dev_ktype
- MD pull requests via Yu Kuai
- Fix raid5_run() to return error when log_init() fails
- Fix IO hang with degraded array with llbitmap
- Fix percpu_ref not resurrected on suspend timeout in llbitmap
- Fix GPF in write_page caused by resize race
- Fix NULL pointer dereference in process_metadata_update
- Fix hang when stopping arrays with metadata through dm-raid
- Fix any_working flag handling in raid10_sync_request
- Refactor sync/recovery code path, improve error handling for
badblocks, and remove unused recovery_disabled field
- Consolidate mddev boolean fields into mddev_flags
- Use mempool to allocate stripe_request_ctx and make sure
max_sectors is not less than io_opt in raid5
- Fix return value of mddev_trylock
- Fix memory leak in raid1_run()
- Add Li Nan as mdraid reviewer
- Move phys_vec definitions to the kernel types, mostly in preparation
for some VFIO and RDMA changes
- Improve the speed for secure erase for some devices
- Various little rust updates
- Various other minor fixes, improvements, and cleanups
* tag 'for-7.0/block-20260206' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (162 commits)
blk-mq: ABI/sysfs-block: fix docs build warnings
selftests: ublk: organize test directories by test ID
block: decouple secure erase size limit from discard size limit
block: remove redundant kill_bdev() call in set_blocksize()
blk-mq: add documentation for new queue attribute async_dpeth
block, bfq: convert to use request_queue->async_depth
mq-deadline: covert to use request_queue->async_depth
kyber: covert to use request_queue->async_depth
blk-mq: add a new queue sysfs attribute async_depth
blk-mq: factor out a helper blk_mq_limit_depth()
blk-mq-sched: unify elevators checking for async requests
block: convert nr_requests to unsigned int
block: don't use strcpy to copy blockdev name
blk-mq-debugfs: warn about possible deadlock
blk-mq-debugfs: add missing debugfs_mutex in blk_mq_debugfs_register_hctxs()
blk-mq-debugfs: remove blk_mq_debugfs_unregister_rqos()
blk-mq-debugfs: make blk_mq_debugfs_register_rqos() static
blk-rq-qos: fix possible debugfs_mutex deadlock
blk-mq-debugfs: factor out a helper to register debugfs for all rq_qos
blk-wbt: fix possible deadlock to nest pcpu_alloc_mutex under q_usage_counter
...
For potential long term allocations, ensure that we play nicer with
memcg and use the accounting variant of the GFP_KERNEL allocation.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_import_kbuf() recalculates iter->nr_segs to reflect only the bvecs
needed for the requested byte range. This was added to provide an
accurate segment count to bio_iov_bvec_set(), which copied nr_segs to
bio->bi_vcnt for use as a bio split hint.
The previous two patches eliminated this dependency:
- bio_may_need_split() now uses bi_iter instead of bi_vcnt for split
decisions
- bio_iov_bvec_set() no longer copies nr_segs to bi_vcnt
Since nr_segs is no longer used for bio split decisions, the
recalculation loop is unnecessary. The iov_iter already has the correct
bi_size to cap iteration, so an oversized nr_segs is harmless.
Link: https://lkml.org/lkml/2025/4/16/351
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_import_kbuf() calculates nr_segs incorrectly when iov_offset is
non-zero after iov_iter_advance(). It doesn't account for the partial
consumption of the first bvec.
The problem comes when meet the following conditions:
1. Use UBLK_F_AUTO_BUF_REG feature of ublk.
2. The kernel will help to register the buffer, into the io uring.
3. Later, the ublk server try to send IO request using the registered
buffer in the io uring, to read/write to fuse-based filesystem, with
O_DIRECT.
>From a userspace perspective, the ublk server thread is blocked in the
kernel, and will see "soft lockup" in the kernel dmesg.
When ublk registers a buffer with mixed-size bvecs like [4K]*6 + [12K]
and a request partially consumes a bvec, the next request's nr_segs
calculation uses bvec->bv_len instead of (bv_len - iov_offset).
This causes fuse_get_user_pages() to loop forever because nr_segs
indicates fewer pages than actually needed.
Specifically, the infinite loop happens at:
fuse_get_user_pages()
-> iov_iter_extract_pages()
-> iov_iter_extract_bvec_pages()
Since the nr_segs is miscalculated, the iov_iter_extract_bvec_pages
returns when finding that i->nr_segs is zero. Then
iov_iter_extract_pages returns zero. However, fuse_get_user_pages does
still not get enough data/pages, causing infinite loop.
Example:
- Bvecs: [4K, 4K, 4K, 4K, 4K, 4K, 12K, ...]
- Request 1: 32K at offset 0, uses 6*4K + 8K of the 12K bvec
- Request 2: 32K at offset 32K
- iov_offset = 8K (8K already consumed from 12K bvec)
- Bug: calculates using 12K, not (12K - 8K) = 4K
- Result: nr_segs too small, infinite loop in fuse_get_user_pages.
Fix by accounting for iov_offset when calculating the first segment's
available length.
Fixes: b419bed4f0 ("io_uring/rsrc: ensure segments counts are correct on kbuf buffers")
Signed-off-by: huang-jl <huang-jl@deepseek.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When cloning with node replacements (IORING_REGISTER_DST_REPLACE),
destination entries after the cloned range are not copied over.
Add logic to copy them over to the new destination table.
Fixes: c1329532d5 ("io_uring/rsrc: allow cloning with node replacements")
Cc: stable@vger.kernel.org
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The variable holds nodes from the destination ring's existing buffer
table. In io_clone_buffers(), the term "src" is used to refer to the
source ring.
Rename to node for clarity.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Get rid of some redundant checks and move the src arg validation to
before the buffer table allocation, which simplifies error handling.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge 6.18-rc io_uring fixes, as certain coming changes depend on some
of these.
* io_uring-6.18:
io_uring/rsrc: don't use blk_rq_nr_phys_segments() as number of bvecs
io_uring/query: return number of available queries
io_uring/rw: ensure allocated iovec gets cleared for early failure
io_uring: fix regbuf vector size truncation
io_uring: fix types for region size calulation
io_uring/zcrx: remove sync refill uapi
io_uring: fix buffer auto-commit for multishot uring_cmd
io_uring: correct __must_hold annotation in io_install_fixed_file
io_uring zcrx: add MAINTAINERS entry
io_uring: Fix code indentation error
io_uring/sqpoll: be smarter on when to update the stime usage
io_uring/sqpoll: switch away from getrusage() for CPU accounting
io_uring: fix incorrect unlikely() usage in io_waitid_prep()
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_buffer_register_bvec() currently uses blk_rq_nr_phys_segments() as
the number of bvecs in the request. However, bvecs may be split into
multiple segments depending on the queue limits. Thus, the number of
segments may overestimate the number of bvecs. For ublk devices, the
only current users of io_buffer_register_bvec(), virt_boundary_mask,
seg_boundary_mask, max_segments, and max_segment_size can all be set
arbitrarily by the ublk server process.
Set imu->nr_bvecs based on the number of bvecs the rq_for_each_bvec()
loop actually yields. However, continue using blk_rq_nr_phys_segments()
as an upper bound on the number of bvecs when allocating imu to avoid
needing to iterate the bvecs a second time.
Link: https://lore.kernel.org/io-uring/20251111191530.1268875-1-csander@purestorage.com/
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Fixes: 27cb27b6d5 ("io_uring: add support for kernel registered bvecs")
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Refactor io_{un}account_mem() to take user_struct and mm_struct
directly, instead of accessing it from the ring ctx.
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe
Linus Torvalds
Jackie LiuandJens Axboe
Qi TangandJens Axboe
Kees Cook
Pavel BegunkovandJens Axboe
Ming LeiandJens Axboe
huang-jlandJens Axboe
Joanne KoongandJens Axboe
Caleb Sander MateosandJens Axboe
David WeiandJens Axboe