From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- io_uring/openclose.c | 448 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 448 insertions(+) create mode 100644 io_uring/openclose.c (limited to 'io_uring/openclose.c') diff --git a/io_uring/openclose.c b/io_uring/openclose.c new file mode 100644 index 000000000..c71242915 --- /dev/null +++ b/io_uring/openclose.c @@ -0,0 +1,448 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "../fs/internal.h" + +#include "filetable.h" +#include "io_uring.h" +#include "rsrc.h" +#include "openclose.h" + +struct io_open { + struct file *file; + int dfd; + u32 file_slot; + struct delayed_filename filename; + struct open_how how; + unsigned long nofile; +}; + +struct io_close { + struct file *file; + int fd; + u32 file_slot; +}; + +struct io_fixed_install { + struct file *file; + unsigned int o_flags; +}; + +static bool io_openat_force_async(struct io_open *open) +{ + /* + * Don't bother trying for O_TRUNC, O_CREAT, or O_TMPFILE open, + * it'll always -EAGAIN. Note that we test for __O_TMPFILE because + * O_TMPFILE includes O_DIRECTORY, which isn't a flag we need to force + * async for. + */ + return open->how.flags & (O_TRUNC | O_CREAT | __O_TMPFILE); +} + +static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_open *open = io_kiocb_to_cmd(req, struct io_open); + const char __user *fname; + int ret; + + if (unlikely(sqe->buf_index)) + return -EINVAL; + if (unlikely(req->flags & REQ_F_FIXED_FILE)) + return -EBADF; + + /* open.how should be already initialised */ + if (!(open->how.flags & O_PATH) && force_o_largefile()) + open->how.flags |= O_LARGEFILE; + + open->dfd = READ_ONCE(sqe->fd); + fname = u64_to_user_ptr(READ_ONCE(sqe->addr)); + ret = delayed_getname(&open->filename, fname); + if (unlikely(ret)) + return ret; + req->flags |= REQ_F_NEED_CLEANUP; + + open->file_slot = READ_ONCE(sqe->file_index); + if (open->file_slot && (open->how.flags & O_CLOEXEC)) + return -EINVAL; + + open->nofile = rlimit(RLIMIT_NOFILE); + if (io_openat_force_async(open)) + req->flags |= REQ_F_FORCE_ASYNC; + return 0; +} + +void io_openat_bpf_populate(struct io_uring_bpf_ctx *bctx, struct io_kiocb *req) +{ + struct io_open *open = io_kiocb_to_cmd(req, struct io_open); + + bctx->open.flags = open->how.flags; + bctx->open.mode = open->how.mode; + bctx->open.resolve = open->how.resolve; +} + +int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_open *open = io_kiocb_to_cmd(req, struct io_open); + u64 mode = READ_ONCE(sqe->len); + u64 flags = READ_ONCE(sqe->open_flags); + + open->how = build_open_how(flags, mode); + return __io_openat_prep(req, sqe); +} + +int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_open *open = io_kiocb_to_cmd(req, struct io_open); + struct open_how __user *how; + size_t len; + int ret; + + how = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + len = READ_ONCE(sqe->len); + if (len < OPEN_HOW_SIZE_VER0) + return -EINVAL; + + ret = copy_struct_from_user(&open->how, sizeof(open->how), how, len); + if (ret) + return ret; + + return __io_openat_prep(req, sqe); +} + +int io_openat2(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_open *open = io_kiocb_to_cmd(req, struct io_open); + struct open_flags op; + struct file *file; + bool resolve_nonblock, nonblock_set; + bool fixed = !!open->file_slot; + CLASS(filename_complete_delayed, name)(&open->filename); + int ret; + + ret = build_open_flags(&open->how, &op); + if (ret) + goto err; + nonblock_set = op.open_flag & O_NONBLOCK; + resolve_nonblock = open->how.resolve & RESOLVE_CACHED; + if (issue_flags & IO_URING_F_NONBLOCK) { + WARN_ON_ONCE(io_openat_force_async(open)); + op.lookup_flags |= LOOKUP_CACHED; + op.open_flag |= O_NONBLOCK; + } + + if (!fixed) { + ret = __get_unused_fd_flags(open->how.flags, open->nofile); + if (ret < 0) + goto err; + } + + file = do_file_open(open->dfd, name, &op); + if (IS_ERR(file)) { + /* + * We could hang on to this 'fd' on retrying, but seems like + * marginal gain for something that is now known to be a slower + * path. So just put it, and we'll get a new one when we retry. + */ + if (!fixed) + put_unused_fd(ret); + + ret = PTR_ERR(file); + /* only retry if RESOLVE_CACHED wasn't already set by application */ + if (ret == -EAGAIN && !resolve_nonblock && + (issue_flags & IO_URING_F_NONBLOCK)) { + ret = putname_to_delayed(&open->filename, + no_free_ptr(name)); + if (likely(!ret)) + return -EAGAIN; + } + goto err; + } + + if ((issue_flags & IO_URING_F_NONBLOCK) && !nonblock_set) + file->f_flags &= ~O_NONBLOCK; + + if (!fixed) + fd_install(ret, file); + else + ret = io_fixed_fd_install(req, issue_flags, file, + open->file_slot); +err: + req->flags &= ~REQ_F_NEED_CLEANUP; + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +int io_openat(struct io_kiocb *req, unsigned int issue_flags) +{ + return io_openat2(req, issue_flags); +} + +void io_open_cleanup(struct io_kiocb *req) +{ + struct io_open *open = io_kiocb_to_cmd(req, struct io_open); + + dismiss_delayed_filename(&open->filename); +} + +int __io_close_fixed(struct io_ring_ctx *ctx, unsigned int issue_flags, + unsigned int offset) +{ + int ret; + + io_ring_submit_lock(ctx, issue_flags); + ret = io_fixed_fd_remove(ctx, offset); + io_ring_submit_unlock(ctx, issue_flags); + + return ret; +} + +static inline int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_close *close = io_kiocb_to_cmd(req, struct io_close); + + return __io_close_fixed(req->ctx, issue_flags, close->file_slot - 1); +} + +int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_close *close = io_kiocb_to_cmd(req, struct io_close); + + if (sqe->off || sqe->addr || sqe->len || sqe->rw_flags || sqe->buf_index) + return -EINVAL; + if (req->flags & REQ_F_FIXED_FILE) + return -EBADF; + + close->fd = READ_ONCE(sqe->fd); + close->file_slot = READ_ONCE(sqe->file_index); + if (close->file_slot && close->fd) + return -EINVAL; + + return 0; +} + +int io_close(struct io_kiocb *req, unsigned int issue_flags) +{ + struct files_struct *files = current->files; + struct io_close *close = io_kiocb_to_cmd(req, struct io_close); + struct file *file; + int ret = -EBADF; + + if (close->file_slot) { + ret = io_close_fixed(req, issue_flags); + goto err; + } + + spin_lock(&files->file_lock); + file = files_lookup_fd_locked(files, close->fd); + if (!file || io_is_uring_fops(file)) { + spin_unlock(&files->file_lock); + goto err; + } + + /* if the file has a flush method, be safe and punt to async */ + if (file->f_op->flush && (issue_flags & IO_URING_F_NONBLOCK)) { + spin_unlock(&files->file_lock); + return -EAGAIN; + } + + file = file_close_fd_locked(files, close->fd); + spin_unlock(&files->file_lock); + if (!file) + goto err; + + /* No ->flush() or already async, safely close from here */ + ret = filp_close(file, current->files); +err: + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +int io_install_fixed_fd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_fixed_install *ifi; + unsigned int flags; + + if (sqe->off || sqe->addr || sqe->len || sqe->buf_index || + sqe->splice_fd_in || sqe->addr3) + return -EINVAL; + + /* must be a fixed file */ + if (!(req->flags & REQ_F_FIXED_FILE)) + return -EBADF; + + flags = READ_ONCE(sqe->install_fd_flags); + if (flags & ~IORING_FIXED_FD_NO_CLOEXEC) + return -EINVAL; + + /* ensure the task's creds are used when installing/receiving fds */ + if (req->flags & REQ_F_CREDS) + return -EPERM; + + /* default to O_CLOEXEC, disable if IORING_FIXED_FD_NO_CLOEXEC is set */ + ifi = io_kiocb_to_cmd(req, struct io_fixed_install); + ifi->o_flags = O_CLOEXEC; + if (flags & IORING_FIXED_FD_NO_CLOEXEC) + ifi->o_flags = 0; + + return 0; +} + +int io_install_fixed_fd(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_fixed_install *ifi; + int ret; + + ifi = io_kiocb_to_cmd(req, struct io_fixed_install); + ret = receive_fd(req->file, NULL, ifi->o_flags); + if (ret < 0) + req_set_fail(req); + io_req_set_res(req, ret, 0); + return IOU_COMPLETE; +} + +struct io_pipe { + struct file *file; + int __user *fds; + int flags; + int file_slot; + unsigned long nofile; +}; + +int io_pipe_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe); + + if (sqe->fd || sqe->off || sqe->addr3) + return -EINVAL; + + p->fds = u64_to_user_ptr(READ_ONCE(sqe->addr)); + p->flags = READ_ONCE(sqe->pipe_flags); + if (p->flags & ~(O_CLOEXEC | O_NONBLOCK | O_DIRECT | O_NOTIFICATION_PIPE)) + return -EINVAL; + + p->file_slot = READ_ONCE(sqe->file_index); + p->nofile = rlimit(RLIMIT_NOFILE); + return 0; +} + +static int io_pipe_fixed(struct io_kiocb *req, struct file **files, + unsigned int issue_flags) +{ + struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe); + struct io_ring_ctx *ctx = req->ctx; + bool alloc_slot; + int ret, fds[2] = { -1, -1 }; + int slot = p->file_slot; + + if (p->flags & O_CLOEXEC) + return -EINVAL; + + alloc_slot = slot == IORING_FILE_INDEX_ALLOC; + + io_ring_submit_lock(ctx, issue_flags); + + ret = __io_fixed_fd_install(ctx, files[0], slot); + if (ret < 0) + goto err; + fds[0] = alloc_slot ? ret : slot - 1; + files[0] = NULL; + + /* + * If a specific slot is given, next one will be used for + * the write side. + */ + if (!alloc_slot) + slot++; + + ret = __io_fixed_fd_install(ctx, files[1], slot); + if (ret < 0) + goto err; + fds[1] = alloc_slot ? ret : slot - 1; + files[1] = NULL; + + io_ring_submit_unlock(ctx, issue_flags); + + if (!copy_to_user(p->fds, fds, sizeof(fds))) + return 0; + + ret = -EFAULT; + io_ring_submit_lock(ctx, issue_flags); +err: + if (fds[0] != -1) + io_fixed_fd_remove(ctx, fds[0]); + if (fds[1] != -1) + io_fixed_fd_remove(ctx, fds[1]); + io_ring_submit_unlock(ctx, issue_flags); + return ret; +} + +static int io_pipe_fd(struct io_kiocb *req, struct file **files) +{ + struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe); + int ret, fds[2] = { -1, -1 }; + + ret = __get_unused_fd_flags(p->flags, p->nofile); + if (ret < 0) + goto err; + fds[0] = ret; + + ret = __get_unused_fd_flags(p->flags, p->nofile); + if (ret < 0) + goto err; + fds[1] = ret; + + if (!copy_to_user(p->fds, fds, sizeof(fds))) { + fd_install(fds[0], files[0]); + fd_install(fds[1], files[1]); + return 0; + } + ret = -EFAULT; +err: + if (fds[0] != -1) + put_unused_fd(fds[0]); + if (fds[1] != -1) + put_unused_fd(fds[1]); + return ret; +} + +int io_pipe(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_pipe *p = io_kiocb_to_cmd(req, struct io_pipe); + struct file *files[2]; + int ret; + + ret = create_pipe_files(files, p->flags); + if (ret) + return ret; + + if (!!p->file_slot) + ret = io_pipe_fixed(req, files, issue_flags); + else + ret = io_pipe_fd(req, files); + + io_req_set_res(req, ret, 0); + if (!ret) + return IOU_COMPLETE; + + req_set_fail(req); + if (files[0]) + fput(files[0]); + if (files[1]) + fput(files[1]); + return ret; +} -- cgit v1.3.1