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 --- fs/fuse/notify.c | 446 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 446 insertions(+) create mode 100644 fs/fuse/notify.c (limited to 'fs/fuse/notify.c') diff --git a/fs/fuse/notify.c b/fs/fuse/notify.c new file mode 100644 index 000000000..1ba763705 --- /dev/null +++ b/fs/fuse/notify.c @@ -0,0 +1,446 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include "dev.h" +#include "fuse_i.h" + +#include +#include + +static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size, + struct fuse_copy_state *cs) +{ + struct fuse_notify_poll_wakeup_out outarg; + int err; + + if (size != sizeof(outarg)) + return -EINVAL; + + err = fuse_copy_one(cs, &outarg, sizeof(outarg)); + if (err) + return err; + + fuse_copy_finish(cs); + return fuse_notify_poll_wakeup(fc, &outarg); +} + +static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size, + struct fuse_copy_state *cs) +{ + struct fuse_notify_inval_inode_out outarg; + int err; + + if (size != sizeof(outarg)) + return -EINVAL; + + err = fuse_copy_one(cs, &outarg, sizeof(outarg)); + if (err) + return err; + fuse_copy_finish(cs); + + down_read(&fc->killsb); + err = fuse_reverse_inval_inode(fc, outarg.ino, + outarg.off, outarg.len); + up_read(&fc->killsb); + return err; +} + +static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size, + struct fuse_copy_state *cs) +{ + struct fuse_notify_inval_entry_out outarg; + int err; + char *buf; + struct qstr name; + + if (size < sizeof(outarg)) + return -EINVAL; + + err = fuse_copy_one(cs, &outarg, sizeof(outarg)); + if (err) + return err; + + if (outarg.namelen > fc->name_max) + return -ENAMETOOLONG; + + err = -EINVAL; + if (size != sizeof(outarg) + outarg.namelen + 1) + return -EINVAL; + + buf = kzalloc(outarg.namelen + 1, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + name.name = buf; + name.len = outarg.namelen; + err = fuse_copy_one(cs, buf, outarg.namelen + 1); + if (err) + goto err; + fuse_copy_finish(cs); + buf[outarg.namelen] = 0; + + down_read(&fc->killsb); + err = fuse_reverse_inval_entry(fc, outarg.parent, 0, &name, outarg.flags); + up_read(&fc->killsb); +err: + kfree(buf); + return err; +} + +static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size, + struct fuse_copy_state *cs) +{ + struct fuse_notify_delete_out outarg; + int err; + char *buf; + struct qstr name; + + if (size < sizeof(outarg)) + return -EINVAL; + + err = fuse_copy_one(cs, &outarg, sizeof(outarg)); + if (err) + return err; + + if (outarg.namelen > fc->name_max) + return -ENAMETOOLONG; + + if (size != sizeof(outarg) + outarg.namelen + 1) + return -EINVAL; + + buf = kzalloc(outarg.namelen + 1, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + name.name = buf; + name.len = outarg.namelen; + err = fuse_copy_one(cs, buf, outarg.namelen + 1); + if (err) + goto err; + fuse_copy_finish(cs); + buf[outarg.namelen] = 0; + + down_read(&fc->killsb); + err = fuse_reverse_inval_entry(fc, outarg.parent, outarg.child, &name, 0); + up_read(&fc->killsb); +err: + kfree(buf); + return err; +} + +static int fuse_notify_store(struct fuse_conn *fc, unsigned int size, + struct fuse_copy_state *cs) +{ + struct fuse_notify_store_out outarg; + struct inode *inode; + struct address_space *mapping; + u64 nodeid; + int err; + unsigned int num; + loff_t file_size; + loff_t pos; + loff_t end; + + if (size < sizeof(outarg)) + return -EINVAL; + + err = fuse_copy_one(cs, &outarg, sizeof(outarg)); + if (err) + return err; + + if (size - sizeof(outarg) != outarg.size) + return -EINVAL; + + if (outarg.offset >= MAX_LFS_FILESIZE) + return -EINVAL; + + nodeid = outarg.nodeid; + pos = outarg.offset; + num = min(outarg.size, MAX_LFS_FILESIZE - pos); + + down_read(&fc->killsb); + + err = -ENOENT; + inode = fuse_ilookup(fc, nodeid, NULL); + if (!inode) + goto out_up_killsb; + if (!S_ISREG(inode->i_mode)) { + err = -EINVAL; + goto out_iput; + } + + mapping = inode->i_mapping; + file_size = i_size_read(inode); + end = pos + num; + if (end > file_size) { + file_size = end; + fuse_write_update_attr(inode, file_size, num); + } + + while (num) { + struct folio *folio; + unsigned int folio_offset; + unsigned int nr_bytes; + pgoff_t index = pos >> PAGE_SHIFT; + + folio = filemap_grab_folio(mapping, index); + err = PTR_ERR(folio); + if (IS_ERR(folio)) + goto out_iput; + + folio_offset = offset_in_folio(folio, pos); + nr_bytes = min(num, folio_size(folio) - folio_offset); + + err = fuse_copy_folio(cs, &folio, folio_offset, nr_bytes, 0); + if (!folio_test_uptodate(folio) && !err && folio_offset == 0 && + (nr_bytes == folio_size(folio) || file_size == end)) { + folio_zero_segment(folio, nr_bytes, folio_size(folio)); + iomap_folio_mark_uptodate(folio); + } + folio_unlock(folio); + folio_put(folio); + + if (err) + goto out_iput; + + pos += nr_bytes; + num -= nr_bytes; + } + + err = 0; + +out_iput: + iput(inode); +out_up_killsb: + up_read(&fc->killsb); + return err; +} + +struct fuse_retrieve_args { + struct fuse_args_pages ap; + struct fuse_notify_retrieve_in inarg; +}; + +static void fuse_retrieve_end(struct fuse_args *args, int error) +{ + struct fuse_retrieve_args *ra = + container_of(args, typeof(*ra), ap.args); + + release_pages(ra->ap.folios, ra->ap.num_folios); + kfree(ra); +} + +static int fuse_retrieve(struct fuse_mount *fm, struct inode *inode, + struct fuse_notify_retrieve_out *outarg) +{ + int err; + struct address_space *mapping = inode->i_mapping; + loff_t file_size; + unsigned int num; + unsigned int offset; + size_t total_len = 0; + unsigned int num_pages; + struct fuse_conn *fc = fm->fc; + struct fuse_retrieve_args *ra; + size_t args_size = sizeof(*ra); + struct fuse_args_pages *ap; + struct fuse_args *args; + loff_t pos = outarg->offset; + + offset = offset_in_page(pos); + file_size = i_size_read(inode); + + num = min(outarg->size, fc->max_write); + if (pos > file_size) + num = 0; + else if (num > file_size - pos) + num = file_size - pos; + + num_pages = DIV_ROUND_UP(num + offset, PAGE_SIZE); + num_pages = min(num_pages, fc->max_pages); + num = min(num, num_pages << PAGE_SHIFT); + + args_size += num_pages * (sizeof(ap->folios[0]) + sizeof(ap->descs[0])); + + ra = kzalloc(args_size, GFP_KERNEL); + if (!ra) + return -ENOMEM; + + ap = &ra->ap; + ap->folios = (void *) (ra + 1); + ap->descs = (void *) (ap->folios + num_pages); + + args = &ap->args; + args->nodeid = outarg->nodeid; + args->opcode = FUSE_NOTIFY_REPLY; + args->in_numargs = 3; + args->in_pages = true; + args->end = fuse_retrieve_end; + + while (num && ap->num_folios < num_pages) { + struct folio *folio; + unsigned int folio_offset; + unsigned int nr_bytes; + pgoff_t index = pos >> PAGE_SHIFT; + + folio = filemap_get_folio(mapping, index); + if (IS_ERR(folio)) + break; + if (!folio_test_uptodate(folio)) { + folio_put(folio); + break; + } + + folio_offset = offset_in_folio(folio, pos); + nr_bytes = min(folio_size(folio) - folio_offset, num); + + ap->folios[ap->num_folios] = folio; + ap->descs[ap->num_folios].offset = folio_offset; + ap->descs[ap->num_folios].length = nr_bytes; + ap->num_folios++; + + pos += nr_bytes; + num -= nr_bytes; + total_len += nr_bytes; + } + ra->inarg.offset = outarg->offset; + ra->inarg.size = total_len; + fuse_set_zero_arg0(args); + args->in_args[1].size = sizeof(ra->inarg); + args->in_args[1].value = &ra->inarg; + args->in_args[2].size = total_len; + + err = fuse_simple_notify_reply(fm, args, outarg->notify_unique); + if (err) + fuse_retrieve_end(args, err); + + return err; +} + +static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size, + struct fuse_copy_state *cs) +{ + struct fuse_notify_retrieve_out outarg; + struct fuse_mount *fm; + struct inode *inode; + u64 nodeid; + int err; + + if (size != sizeof(outarg)) + return -EINVAL; + + err = fuse_copy_one(cs, &outarg, sizeof(outarg)); + if (err) + return err; + + fuse_copy_finish(cs); + + if (outarg.offset >= MAX_LFS_FILESIZE) + return -EINVAL; + + down_read(&fc->killsb); + err = -ENOENT; + nodeid = outarg.nodeid; + + inode = fuse_ilookup(fc, nodeid, &fm); + if (inode) { + err = -EINVAL; + if (S_ISREG(inode->i_mode)) + err = fuse_retrieve(fm, inode, &outarg); + iput(inode); + } + up_read(&fc->killsb); + + return err; +} + +static int fuse_notify_resend(struct fuse_conn *fc) +{ + fuse_chan_resend(fc->chan); + return 0; +} + +/* + * Increments the fuse connection epoch. This will cause dentries and + * readdir caches from previous epochs to be invalidated. Additionally, + * if inval_wq is set, a work queue is scheduled to trigger the invalidation. + */ +static int fuse_notify_inc_epoch(struct fuse_conn *fc) +{ + atomic_inc(&fc->epoch); + if (inval_wq) + schedule_work(&fc->epoch_work); + + return 0; +} + +static int fuse_notify_prune(struct fuse_conn *fc, unsigned int size, + struct fuse_copy_state *cs) +{ + struct fuse_notify_prune_out outarg; + const unsigned int batch = 512; + u64 *nodeids __free(kfree) = kmalloc(sizeof(u64) * batch, GFP_KERNEL); + unsigned int num, i; + int err; + + if (!nodeids) + return -ENOMEM; + + if (size < sizeof(outarg)) + return -EINVAL; + + err = fuse_copy_one(cs, &outarg, sizeof(outarg)); + if (err) + return err; + + if (size - sizeof(outarg) != array_size(outarg.count, sizeof(u64))) + return -EINVAL; + + for (; outarg.count; outarg.count -= num) { + num = min(batch, outarg.count); + err = fuse_copy_one(cs, nodeids, num * sizeof(u64)); + if (err) + return err; + + scoped_guard(rwsem_read, &fc->killsb) { + for (i = 0; i < num; i++) + fuse_try_prune_one_inode(fc, nodeids[i]); + } + } + return 0; +} + +int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code, + unsigned int size, struct fuse_copy_state *cs) +{ + switch (code) { + case FUSE_NOTIFY_POLL: + return fuse_notify_poll(fc, size, cs); + + case FUSE_NOTIFY_INVAL_INODE: + return fuse_notify_inval_inode(fc, size, cs); + + case FUSE_NOTIFY_INVAL_ENTRY: + return fuse_notify_inval_entry(fc, size, cs); + + case FUSE_NOTIFY_STORE: + return fuse_notify_store(fc, size, cs); + + case FUSE_NOTIFY_RETRIEVE: + return fuse_notify_retrieve(fc, size, cs); + + case FUSE_NOTIFY_DELETE: + return fuse_notify_delete(fc, size, cs); + + case FUSE_NOTIFY_RESEND: + return fuse_notify_resend(fc); + + case FUSE_NOTIFY_INC_EPOCH: + return fuse_notify_inc_epoch(fc); + + case FUSE_NOTIFY_PRUNE: + return fuse_notify_prune(fc, size, cs); + + default: + return -EINVAL; + } +} -- cgit v1.3.1