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2020-12-09io_uring: simplify io_task_match()Pavel Begunkov
If IORING_SETUP_SQPOLL is set all requests belong to the corresponding SQPOLL task, so skip task checking in that case and always match. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09io_uring: inline io_import_iovec()Pavel Begunkov
Inline io_import_iovec() and leave only its former __io_import_iovec() renamed to the original name. That makes it more obious what is reused in io_read/write(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09io_uring: remove duplicated io_size from rwPavel Begunkov
io_size and iov_count in io_read() and io_write() hold the same value, kill the last one. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09fs/io_uring Don't use the return value from import_iovec().David Laight
This is the only code that relies on import_iovec() returning iter.count on success. This allows a better interface to import_iovec(). Signed-off-by: David Laight <david.laight@aculab.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09io_uring: NULL files dereference by SQPOLLPavel Begunkov
SQPOLL task may find sqo_task->files == NULL and __io_sq_thread_acquire_files() would leave it unset, so following fget_many() and others try to dereference NULL and fault. Propagate an error files are missing. [ 118.962785] BUG: kernel NULL pointer dereference, address: 0000000000000020 [ 118.963812] #PF: supervisor read access in kernel mode [ 118.964534] #PF: error_code(0x0000) - not-present page [ 118.969029] RIP: 0010:__fget_files+0xb/0x80 [ 119.005409] Call Trace: [ 119.005651] fget_many+0x2b/0x30 [ 119.005964] io_file_get+0xcf/0x180 [ 119.006315] io_submit_sqes+0x3a4/0x950 [ 119.007481] io_sq_thread+0x1de/0x6a0 [ 119.007828] kthread+0x114/0x150 [ 119.008963] ret_from_fork+0x22/0x30 Reported-by: Josef Grieb <josef.grieb@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09io_uring: add timeout support for io_uring_enter()Hao Xu
Now users who want to get woken when waiting for events should submit a timeout command first. It is not safe for applications that split SQ and CQ handling between two threads, such as mysql. Users should synchronize the two threads explicitly to protect SQ and that will impact the performance. This patch adds support for timeout to existing io_uring_enter(). To avoid overloading arguments, it introduces a new parameter structure which contains sigmask and timeout. I have tested the workloads with one thread submiting nop requests while the other reaping the cqe with timeout. It shows 1.8~2x faster when the iodepth is 16. Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com> Signed-off-by: Hao Xu <haoxu@linux.alibaba.com> [axboe: various cleanups/fixes, and name change to SIG_IS_DATA] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09io_uring: only plug when appropriateJens Axboe
We unconditionally call blk_start_plug() when starting the IO submission, but we only really should do that if we have more than 1 request to submit AND we're potentially dealing with block based storage underneath. For any other type of request, it's just a waste of time to do so. Add a ->plug bit to io_op_def and set it for read/write requests. We could make this more precise and check the file itself as well, but it doesn't matter that much and would quickly become more expensive. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09io_uring: rearrange io_kiocb fields for better cachingPavel Begunkov
We've got extra 8 bytes in the 2nd cacheline, put ->fixed_file_refs there, so inline execution path mostly doesn't touch the 3rd cacheline for fixed_file requests as well. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09io_uring: link requests with singly linked listPavel Begunkov
Singly linked list for keeping linked requests is enough, because we almost always operate on the head and traverse forward with the exception of linked timeouts going 1 hop backwards. Replace ->link_list with a handmade singly linked list. Also kill REQ_F_LINK_HEAD in favour of checking a newly added ->list for NULL directly. That saves 8B in io_kiocb, is not as heavy as list fixup, makes better use of cache by not touching a previous request (i.e. last request of the link) each time on list modification and optimises cache use further in the following patch, and actually makes travesal easier removing in the end some lines. Also, keeping invariant in ->list instead of having REQ_F_LINK_HEAD is less error-prone. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09io_uring: track link timeout's master explicitlyPavel Begunkov
In preparation for converting singly linked lists for chaining requests, make linked timeouts save requests that they're responsible for and not count on doubly linked list for back referencing. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09io_uring: track link's head and tail during submitPavel Begunkov
Explicitly save not only a link's head in io_submit_sqe[s]() but the tail as well. That's in preparation for keeping linked requests in a singly linked list. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09io_uring: split poll and poll_remove structsPavel Begunkov
Don't use a single struct for polls and poll remove requests, they have totally different layouts. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09io_uring: add support for IORING_OP_UNLINKATJens Axboe
IORING_OP_UNLINKAT behaves like unlinkat(2) and takes the same flags and arguments. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09io_uring: add support for IORING_OP_RENAMEATJens Axboe
IORING_OP_RENAMEAT behaves like renameat2(), and takes the same flags etc. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09io_uring: enable file table usage for SQPOLL ringsJens Axboe
Now that SQPOLL supports non-registered files and grabs the file table, we can relax the restriction on open/close/accept/connect and allow them on a ring that is setup with IORING_SETUP_SQPOLL. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-09io_uring: allow non-fixed files with SQPOLLJens Axboe
The restriction of needing fixed files for SQPOLL is problematic, and prevents/inhibits several valid uses cases. With the referenced files_struct that we have now, it's trivially supportable. Treat ->files like we do the mm for the SQPOLL thread - grab a reference to it (and assign it), and drop it when we're done. This feature is exposed as IORING_FEAT_SQPOLL_NONFIXED. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-08io_uring: fix file leak on error path of io ctx creationHillf Danton
Put file as part of error handling when setting up io ctx to fix memory leaks like the following one. BUG: memory leak unreferenced object 0xffff888101ea2200 (size 256): comm "syz-executor355", pid 8470, jiffies 4294953658 (age 32.400s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 20 59 03 01 81 88 ff ff 80 87 a8 10 81 88 ff ff Y.............. backtrace: [<000000002e0a7c5f>] kmem_cache_zalloc include/linux/slab.h:654 [inline] [<000000002e0a7c5f>] __alloc_file+0x1f/0x130 fs/file_table.c:101 [<000000001a55b73a>] alloc_empty_file+0x69/0x120 fs/file_table.c:151 [<00000000fb22349e>] alloc_file+0x33/0x1b0 fs/file_table.c:193 [<000000006e1465bb>] alloc_file_pseudo+0xb2/0x140 fs/file_table.c:233 [<000000007118092a>] anon_inode_getfile fs/anon_inodes.c:91 [inline] [<000000007118092a>] anon_inode_getfile+0xaa/0x120 fs/anon_inodes.c:74 [<000000002ae99012>] io_uring_get_fd fs/io_uring.c:9198 [inline] [<000000002ae99012>] io_uring_create fs/io_uring.c:9377 [inline] [<000000002ae99012>] io_uring_setup+0x1125/0x1630 fs/io_uring.c:9411 [<000000008280baad>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 [<00000000685d8cf0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported-by: syzbot+71c4697e27c99fddcf17@syzkaller.appspotmail.com Fixes: 0f2122045b94 ("io_uring: don't rely on weak ->files references") Cc: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Hillf Danton <hdanton@sina.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-07io_uring: fix mis-seting personality's credsPavel Begunkov
After io_identity_cow() copies an work.identity it wants to copy creds to the new just allocated id, not the old one. Otherwise it's akin to req->work.identity->creds = req->work.identity->creds. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-04net: Remove the err argument from sock_from_fileFlorent Revest
Currently, the sock_from_file prototype takes an "err" pointer that is either not set or set to -ENOTSOCK IFF the returned socket is NULL. This makes the error redundant and it is ignored by a few callers. This patch simplifies the API by letting callers deduce the error based on whether the returned socket is NULL or not. Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Florent Revest <revest@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: KP Singh <kpsingh@google.com> Link: https://lore.kernel.org/bpf/20201204113609.1850150-1-revest@google.com
2020-12-01block: remove i_bdevChristoph Hellwig
Switch the block device lookup interfaces to directly work with a dev_t so that struct block_device references are only acquired by the blkdev_get variants (and the blk-cgroup special case). This means that we now don't need an extra reference in the inode and can generally simplify handling of struct block_device to keep the lookups contained in the core block layer code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Coly Li <colyli@suse.de> [bcache] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-30io_uring: fix recvmsg setup with compat buf-selectPavel Begunkov
__io_compat_recvmsg_copy_hdr() with REQ_F_BUFFER_SELECT reads out iov len but never assigns it to iov/fast_iov, leaving sr->len with garbage. Hopefully, following io_buffer_select() truncates it to the selected buffer size, but the value is still may be under what was specified. Cc: <stable@vger.kernel.org> # 5.7 Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-26io_uring: fix files grab/cancel racePavel Begunkov
When one task is in io_uring_cancel_files() and another is doing io_prep_async_work() a race may happen. That's because after accounting a request inflight in first call to io_grab_identity() it still may fail and go to io_identity_cow(), which migh briefly keep dangling work.identity and not only. Grab files last, so io_prep_async_work() won't fail if it did get into ->inflight_list. note: the bug shouldn't exist after making io_uring_cancel_files() not poking into other tasks' requests. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-24io_uring: fix ITER_BVEC checkPavel Begunkov
iov_iter::type is a bitmask that also keeps direction etc., so it shouldn't be directly compared against ITER_*. Use proper helper. Fixes: ff6165b2d7f6 ("io_uring: retain iov_iter state over io_read/io_write calls") Reported-by: David Howells <dhowells@redhat.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Cc: <stable@vger.kernel.org> # 5.9 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-24io_uring: fix shift-out-of-bounds when round up cq sizeJoseph Qi
Abaci Fuzz reported a shift-out-of-bounds BUG in io_uring_create(): [ 59.598207] UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13 [ 59.599665] shift exponent 64 is too large for 64-bit type 'long unsigned int' [ 59.601230] CPU: 0 PID: 963 Comm: a.out Not tainted 5.10.0-rc4+ #3 [ 59.602502] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 [ 59.603673] Call Trace: [ 59.604286] dump_stack+0x107/0x163 [ 59.605237] ubsan_epilogue+0xb/0x5a [ 59.606094] __ubsan_handle_shift_out_of_bounds.cold+0xb2/0x20e [ 59.607335] ? lock_downgrade+0x6c0/0x6c0 [ 59.608182] ? rcu_read_lock_sched_held+0xaf/0xe0 [ 59.609166] io_uring_create.cold+0x99/0x149 [ 59.610114] io_uring_setup+0xd6/0x140 [ 59.610975] ? io_uring_create+0x2510/0x2510 [ 59.611945] ? lockdep_hardirqs_on_prepare+0x286/0x400 [ 59.613007] ? syscall_enter_from_user_mode+0x27/0x80 [ 59.614038] ? trace_hardirqs_on+0x5b/0x180 [ 59.615056] do_syscall_64+0x2d/0x40 [ 59.615940] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 59.617007] RIP: 0033:0x7f2bb8a0b239 This is caused by roundup_pow_of_two() if the input entries larger enough, e.g. 2^32-1. For sq_entries, it will check first and we allow at most IORING_MAX_ENTRIES, so it is okay. But for cq_entries, we do round up first, that may overflow and truncate it to 0, which is not the expected behavior. So check the cq size first and then do round up. Fixes: 88ec3211e463 ("io_uring: round-up cq size before comparing with rounded sq size") Reported-by: Abaci Fuzz <abaci@linux.alibaba.com> Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-23io_uring: add support for shutdown(2)Jens Axboe
This adds support for the shutdown(2) system call, which is useful for dealing with sockets. shutdown(2) may block, so we have to punt it to async context. Suggested-by: Norman Maurer <norman.maurer@googlemail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-23io_uring: allow SQPOLL with CAP_SYS_NICE privilegesJens Axboe
CAP_SYS_ADMIN is too restrictive for a lot of uses cases, allow CAP_SYS_NICE based on the premise that such users are already allowed to raise the priority of tasks. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-20Merge tag 'io_uring-5.10-2020-11-20' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull io_uring fixes from Jens Axboe: "Mostly regression or stable fodder: - Disallow async path resolution of /proc/self - Tighten constraints for segmented async buffered reads - Fix double completion for a retry error case - Fix for fixed file life times (Pavel)" * tag 'io_uring-5.10-2020-11-20' of git://git.kernel.dk/linux-block: io_uring: order refnode recycling io_uring: get an active ref_node from files_data io_uring: don't double complete failed reissue request mm: never attempt async page lock if we've transferred data already io_uring: handle -EOPNOTSUPP on path resolution proc: don't allow async path resolution of /proc/self components
2020-11-18io_uring: order refnode recyclingPavel Begunkov
Don't recycle a refnode until we're done with all requests of nodes ejected before. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Cc: stable@vger.kernel.org # v5.7+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-18io_uring: get an active ref_node from files_dataPavel Begunkov
An active ref_node always can be found in ctx->files_data, it's much safer to get it this way instead of poking into files_data->ref_list. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Cc: stable@vger.kernel.org # v5.7+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-17io_uring: don't double complete failed reissue requestJens Axboe
Zorro reports that an xfstest test case is failing, and it turns out that for the reissue path we can potentially issue a double completion on the request for the failure path. There's an issue around the retry as well, but for now, at least just make sure that we handle the error path correctly. Cc: stable@vger.kernel.org Fixes: b63534c41e20 ("io_uring: re-issue block requests that failed because of resources") Reported-by: Zorro Lang <zlang@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-14io_uring: handle -EOPNOTSUPP on path resolutionJens Axboe
Any attempt to do path resolution on /proc/self from an async worker will yield -EOPNOTSUPP. We can safely do that resolution from the task itself, and without blocking, so retry it from there. Ideally io_uring would know this upfront and not have to go through the worker thread to find out, but that doesn't currently seem feasible. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-13Merge tag 'vfs-5.10-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds
Pull fs freeze fix and cleanups from Darrick Wong: "A single vfs fix for 5.10, along with two subsequent cleanups. A very long time ago, a hack was added to the vfs fs freeze protection code to work around lockdep complaints about XFS, which would try to run a transaction (which requires intwrite protection) to finalize an xfs freeze (by which time the vfs had already taken intwrite). Fast forward a few years, and XFS fixed the recursive intwrite problem on its own, and the hack became unnecessary. Fast forward almost a decade, and latent bugs in the code converting this hack from freeze flags to freeze locks combine with lockdep bugs to make this reproduce frequently enough to notice page faults racing with freeze. Since the hack is unnecessary and causes thread race errors, just get rid of it completely. Making this kind of vfs change midway through a cycle makes me nervous, but a large enough number of the usual VFS/ext4/XFS/btrfs suspects have said this looks good and solves a real problem vector. And once that removal is done, __sb_start_write is now simple enough that it becomes possible to refactor the function into smaller, simpler static inline helpers in linux/fs.h. The cleanup is straightforward. Summary: - Finally remove the "convert to trylock" weirdness in the fs freezer code. It was necessary 10 years ago to deal with nested transactions in XFS, but we've long since removed that; and now this is causing subtle race conditions when lockdep goes offline and sb_start_* aren't prepared to retry a trylock failure. - Minor cleanups of the sb_start_* fs freeze helpers" * tag 'vfs-5.10-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: vfs: move __sb_{start,end}_write* to fs.h vfs: separate __sb_start_write into blocking and non-blocking helpers vfs: remove lockdep bogosity in __sb_start_write
2020-11-11io_uring: round-up cq size before comparing with rounded sq sizeJens Axboe
If an application specifies IORING_SETUP_CQSIZE to set the CQ ring size to a specific size, we ensure that the CQ size is at least that of the SQ ring size. But in doing so, we compare the already rounded up to power of two SQ size to the as-of yet unrounded CQ size. This means that if an application passes in non power of two sizes, we can return -EINVAL when the final value would've been fine. As an example, an application passing in 100/100 for sq/cq size should end up with 128 for both. But since we round the SQ size first, we compare the CQ size of 100 to 128, and return -EINVAL as that is too small. Cc: stable@vger.kernel.org Fixes: 33a107f0a1b8 ("io_uring: allow application controlled CQ ring size") Reported-by: Dan Melnic <dmm@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-10vfs: separate __sb_start_write into blocking and non-blocking helpersDarrick J. Wong
Break this function into two helpers so that it's obvious that the trylock versions return a value that must be checked, and the blocking versions don't require that. While we're at it, clean up the return type mismatch. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-11-05io_uring: fix link lookup racing with link timeoutPavel Begunkov
We can't just go over linked requests because it may race with linked timeouts. Take ctx->completion_lock in that case. Cc: stable@vger.kernel.org # v5.7+ Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-05io_uring: use correct pointer for io_uring_show_cred()Jens Axboe
Previous commit changed how we index the registered credentials, but neglected to update one spot that is used when the personalities are iterated through ->show_fdinfo(). Ensure we use the right struct type for the iteration. Reported-by: syzbot+a6d494688cdb797bdfce@syzkaller.appspotmail.com Fixes: 1e6fa5216a0e ("io_uring: COW io_identity on mismatch") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-05io_uring: don't forget to task-cancel drained reqsPavel Begunkov
If there is a long-standing request of one task locking up execution of deferred requests, and the defer list contains requests of another task (all files-less), then a potential execution of __io_uring_task_cancel() by that another task will sleep until that first long-standing request completion, and that may take long. E.g. tsk1: req1/read(empty_pipe) -> tsk2: req(DRAIN) Then __io_uring_task_cancel(tsk2) waits for req1 completion. It seems we even can manufacture a complicated case with many tasks sharing many rings that can lock them forever. Cancel deferred requests for __io_uring_task_cancel() as well. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-04io_uring: fix overflowed cancel w/ linked ->filesPavel Begunkov
Current io_match_files() check in io_cqring_overflow_flush() is useless because requests drop ->files before going to the overflow list, however linked to it request do not, and we don't check them. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-04io_uring: drop req/tctx io_identity separatelyJens Axboe
We can't bundle this into one operation, as the identity may not have originated from the tctx to begin with. Drop one ref for each of them separately, if they don't match the static assignment. If we don't, then if the identity is a lookup from registered credentials, we could be freeing that identity as we're dropping a reference assuming it came from the tctx. syzbot reports this as a use-after-free, as the identity is still referencable from idr lookup: ================================================================== BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline] BUG: KASAN: use-after-free in atomic_fetch_add_relaxed include/asm-generic/atomic-instrumented.h:142 [inline] BUG: KASAN: use-after-free in __refcount_add include/linux/refcount.h:193 [inline] BUG: KASAN: use-after-free in __refcount_inc include/linux/refcount.h:250 [inline] BUG: KASAN: use-after-free in refcount_inc include/linux/refcount.h:267 [inline] BUG: KASAN: use-after-free in io_init_req fs/io_uring.c:6700 [inline] BUG: KASAN: use-after-free in io_submit_sqes+0x15a9/0x25f0 fs/io_uring.c:6774 Write of size 4 at addr ffff888011e08e48 by task syz-executor165/8487 CPU: 1 PID: 8487 Comm: syz-executor165 Not tainted 5.10.0-rc1-next-20201102-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0x13d/0x180 mm/kasan/generic.c:192 instrument_atomic_read_write include/linux/instrumented.h:101 [inline] atomic_fetch_add_relaxed include/asm-generic/atomic-instrumented.h:142 [inline] __refcount_add include/linux/refcount.h:193 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] io_init_req fs/io_uring.c:6700 [inline] io_submit_sqes+0x15a9/0x25f0 fs/io_uring.c:6774 __do_sys_io_uring_enter+0xc8e/0x1b50 fs/io_uring.c:9159 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x440e19 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 0f fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff644ff178 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000440e19 RDX: 0000000000000000 RSI: 000000000000450c RDI: 0000000000000003 RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000022b4850 R13: 0000000000000010 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 8487: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:461 kmalloc include/linux/slab.h:552 [inline] io_register_personality fs/io_uring.c:9638 [inline] __io_uring_register fs/io_uring.c:9874 [inline] __do_sys_io_uring_register+0x10f0/0x40a0 fs/io_uring.c:9924 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 8487: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0x102/0x140 mm/kasan/common.c:422 slab_free_hook mm/slub.c:1544 [inline] slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1577 slab_free mm/slub.c:3140 [inline] kfree+0xdb/0x360 mm/slub.c:4122 io_identity_cow fs/io_uring.c:1380 [inline] io_prep_async_work+0x903/0xbc0 fs/io_uring.c:1492 io_prep_async_link fs/io_uring.c:1505 [inline] io_req_defer fs/io_uring.c:5999 [inline] io_queue_sqe+0x212/0xed0 fs/io_uring.c:6448 io_submit_sqe fs/io_uring.c:6542 [inline] io_submit_sqes+0x14f6/0x25f0 fs/io_uring.c:6784 __do_sys_io_uring_enter+0xc8e/0x1b50 fs/io_uring.c:9159 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff888011e08e00 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 72 bytes inside of 96-byte region [ffff888011e08e00, ffff888011e08e60) The buggy address belongs to the page: page:00000000a7104751 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11e08 flags: 0xfff00000000200(slab) raw: 00fff00000000200 ffffea00004f8540 0000001f00000002 ffff888010041780 raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888011e08d00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ffff888011e08d80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc > ffff888011e08e00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888011e08e80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ffff888011e08f00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ================================================================== Reported-by: syzbot+625ce3bb7835b63f7f3d@syzkaller.appspotmail.com Fixes: 1e6fa5216a0e ("io_uring: COW io_identity on mismatch") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-04io_uring: ensure consistent view of original task ->mm from SQPOLLJens Axboe
Ensure we get a valid view of the task mm, by using task_lock() when attempting to grab the original task mm. Reported-by: syzbot+b57abf7ee60829090495@syzkaller.appspotmail.com Fixes: 2aede0e417db ("io_uring: stash ctx task reference for SQPOLL") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-11-04io_uring: properly handle SQPOLL request cancelationsJens Axboe
Track if a given task io_uring context contains SQPOLL instances, so we can iterate those for cancelation (and request counts). This ensures that we properly wait on SQPOLL contexts, and find everything that needs canceling. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-30Merge tag 'io_uring-5.10-2020-10-30' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull io_uring fixes from Jens Axboe: - Fixes for linked timeouts (Pavel) - Set IO_WQ_WORK_CONCURRENT early for async offload (Pavel) - Two minor simplifications that make the code easier to read and follow (Pavel) * tag 'io_uring-5.10-2020-10-30' of git://git.kernel.dk/linux-block: io_uring: use type appropriate io_kiocb handler for double poll io_uring: simplify __io_queue_sqe() io_uring: simplify nxt propagation in io_queue_sqe io_uring: don't miss setting IO_WQ_WORK_CONCURRENT io_uring: don't defer put of cancelled ltimeout io_uring: always clear LINK_TIMEOUT after cancel io_uring: don't adjust LINK_HEAD in cancel ltimeout io_uring: remove opcode check on ltimeout kill
2020-10-25io_uring: use type appropriate io_kiocb handler for double pollJens Axboe
io_poll_double_wake() is called for both request types - both pure poll requests, and internal polls. This means that we should be using the right handler based on the request type. Use the one that the original caller already assigned for the waitqueue handling, that will always match the correct type. Cc: stable@vger.kernel.org # v5.8+ Reported-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-24Merge tag 'io_uring-5.10-2020-10-24' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull io_uring fixes from Jens Axboe: - fsize was missed in previous unification of work flags - Few fixes cleaning up the flags unification creds cases (Pavel) - Fix NUMA affinities for completely unplugged/replugged node for io-wq - Two fallout fixes from the set_fs changes. One local to io_uring, one for the splice entry point that io_uring uses. - Linked timeout fixes (Pavel) - Removal of ->flush() ->files work-around that we don't need anymore with referenced files (Pavel) - Various cleanups (Pavel) * tag 'io_uring-5.10-2020-10-24' of git://git.kernel.dk/linux-block: splice: change exported internal do_splice() helper to take kernel offset io_uring: make loop_rw_iter() use original user supplied pointers io_uring: remove req cancel in ->flush() io-wq: re-set NUMA node affinities if CPUs come online io_uring: don't reuse linked_timeout io_uring: unify fsize with def->work_flags io_uring: fix racy REQ_F_LINK_TIMEOUT clearing io_uring: do poll's hash_node init in common code io_uring: inline io_poll_task_handler() io_uring: remove extra ->file check in poll prep io_uring: make cached_cq_overflow non atomic_t io_uring: inline io_fail_links() io_uring: kill ref get/drop in personality init io_uring: flags-based creds init in queue
2020-10-23io_uring: simplify __io_queue_sqe()Pavel Begunkov
Restructure __io_queue_sqe() so it follows simple if/else if/else control flow. It's more readable and removes extra goto/labels. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-23io_uring: simplify nxt propagation in io_queue_sqePavel Begunkov
Don't overuse goto's, complex control flow doesn't make compilers happy and makes code harder to read. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-23io_uring: don't miss setting IO_WQ_WORK_CONCURRENTPavel Begunkov
Set IO_WQ_WORK_CONCURRENT for all REQ_F_FORCE_ASYNC requests, do that in that is also looks better. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-23io_uring: don't defer put of cancelled ltimeoutPavel Begunkov
Inline io_link_cancel_timeout() and __io_kill_linked_timeout() into io_kill_linked_timeout(). That allows to easily move a put of a cancelled linked timeout out of completion_lock and to not deferring it. It is also much more readable when not scattered across three different functions. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-23io_uring: always clear LINK_TIMEOUT after cancelPavel Begunkov
Move REQ_F_LINK_TIMEOUT clearing out of __io_kill_linked_timeout() because it might return early and leave the flag set. It's not a problem, but may be confusing. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-23io_uring: don't adjust LINK_HEAD in cancel ltimeoutPavel Begunkov
An armed linked timeout can never be a head of a link, so we don't need to clear REQ_F_LINK_HEAD for it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>