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/file_attr.c | 486 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 486 insertions(+) create mode 100644 fs/file_attr.c (limited to 'fs/file_attr.c') diff --git a/fs/file_attr.c b/fs/file_attr.c new file mode 100644 index 000000000..bfb00d256 --- /dev/null +++ b/fs/file_attr.c @@ -0,0 +1,486 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include + +#include "internal.h" + +/** + * fileattr_fill_xflags - initialize fileattr with xflags + * @fa: fileattr pointer + * @xflags: FS_XFLAG_* flags + * + * Set ->fsx_xflags, ->fsx_valid and ->flags (translated xflags). + */ +void fileattr_fill_xflags(struct file_kattr *fa, u32 xflags) +{ + fa->fsx_valid = true; + fa->fsx_xflags = xflags; + if (fa->fsx_xflags & FS_XFLAG_IMMUTABLE) + fa->flags |= FS_IMMUTABLE_FL; + if (fa->fsx_xflags & FS_XFLAG_APPEND) + fa->flags |= FS_APPEND_FL; + if (fa->fsx_xflags & FS_XFLAG_SYNC) + fa->flags |= FS_SYNC_FL; + if (fa->fsx_xflags & FS_XFLAG_NOATIME) + fa->flags |= FS_NOATIME_FL; + if (fa->fsx_xflags & FS_XFLAG_NODUMP) + fa->flags |= FS_NODUMP_FL; + if (fa->fsx_xflags & FS_XFLAG_DAX) + fa->flags |= FS_DAX_FL; + if (fa->fsx_xflags & FS_XFLAG_PROJINHERIT) + fa->flags |= FS_PROJINHERIT_FL; + if (fa->fsx_xflags & FS_XFLAG_VERITY) + fa->flags |= FS_VERITY_FL; + if (fa->fsx_xflags & FS_XFLAG_CASEFOLD) + fa->flags |= FS_CASEFOLD_FL; +} +EXPORT_SYMBOL(fileattr_fill_xflags); + +/** + * fileattr_fill_flags - initialize fileattr with flags + * @fa: fileattr pointer + * @flags: FS_*_FL flags + * + * Set ->flags, ->flags_valid and ->fsx_xflags (translated flags). + */ +void fileattr_fill_flags(struct file_kattr *fa, u32 flags) +{ + fa->flags_valid = true; + fa->flags = flags; + if (fa->flags & FS_SYNC_FL) + fa->fsx_xflags |= FS_XFLAG_SYNC; + if (fa->flags & FS_IMMUTABLE_FL) + fa->fsx_xflags |= FS_XFLAG_IMMUTABLE; + if (fa->flags & FS_APPEND_FL) + fa->fsx_xflags |= FS_XFLAG_APPEND; + if (fa->flags & FS_NODUMP_FL) + fa->fsx_xflags |= FS_XFLAG_NODUMP; + if (fa->flags & FS_NOATIME_FL) + fa->fsx_xflags |= FS_XFLAG_NOATIME; + if (fa->flags & FS_DAX_FL) + fa->fsx_xflags |= FS_XFLAG_DAX; + if (fa->flags & FS_PROJINHERIT_FL) + fa->fsx_xflags |= FS_XFLAG_PROJINHERIT; + if (fa->flags & FS_VERITY_FL) + fa->fsx_xflags |= FS_XFLAG_VERITY; + if (fa->flags & FS_CASEFOLD_FL) + fa->fsx_xflags |= FS_XFLAG_CASEFOLD; +} +EXPORT_SYMBOL(fileattr_fill_flags); + +/** + * vfs_fileattr_get - retrieve miscellaneous file attributes + * @dentry: the object to retrieve from + * @fa: fileattr pointer + * + * Call i_op->fileattr_get() callback, if exists. + * + * Return: 0 on success, or a negative error on failure. + */ +int vfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa) +{ + struct inode *inode = d_inode(dentry); + int error; + + if (!inode->i_op->fileattr_get) + return -ENOIOCTLCMD; + + error = security_inode_file_getattr(dentry, fa); + if (error) + return error; + + return inode->i_op->fileattr_get(dentry, fa); +} +EXPORT_SYMBOL(vfs_fileattr_get); + +static void fileattr_to_file_attr(const struct file_kattr *fa, + struct file_attr *fattr) +{ + __u32 mask = FS_XFLAGS_MASK; + + memset(fattr, 0, sizeof(struct file_attr)); + fattr->fa_xflags = fa->fsx_xflags & mask; + fattr->fa_extsize = fa->fsx_extsize; + fattr->fa_nextents = fa->fsx_nextents; + fattr->fa_projid = fa->fsx_projid; + fattr->fa_cowextsize = fa->fsx_cowextsize; +} + +/** + * copy_fsxattr_to_user - copy fsxattr to userspace. + * @fa: fileattr pointer + * @ufa: fsxattr user pointer + * + * Return: 0 on success, or -EFAULT on failure. + */ +int copy_fsxattr_to_user(const struct file_kattr *fa, struct fsxattr __user *ufa) +{ + struct fsxattr xfa; + __u32 mask = FS_XFLAGS_MASK; + + memset(&xfa, 0, sizeof(xfa)); + xfa.fsx_xflags = fa->fsx_xflags & mask; + xfa.fsx_extsize = fa->fsx_extsize; + xfa.fsx_nextents = fa->fsx_nextents; + xfa.fsx_projid = fa->fsx_projid; + xfa.fsx_cowextsize = fa->fsx_cowextsize; + + if (copy_to_user(ufa, &xfa, sizeof(xfa))) + return -EFAULT; + + return 0; +} +EXPORT_SYMBOL(copy_fsxattr_to_user); + +static int file_attr_to_fileattr(const struct file_attr *fattr, + struct file_kattr *fa) +{ + __u64 mask = FS_XFLAGS_MASK; + + if (fattr->fa_xflags & ~mask) + return -EINVAL; + + fileattr_fill_xflags(fa, fattr->fa_xflags & ~FS_XFLAG_RDONLY_MASK); + fa->fsx_extsize = fattr->fa_extsize; + fa->fsx_projid = fattr->fa_projid; + fa->fsx_cowextsize = fattr->fa_cowextsize; + + return 0; +} + +static int copy_fsxattr_from_user(struct file_kattr *fa, + struct fsxattr __user *ufa) +{ + struct fsxattr xfa; + __u32 mask = FS_XFLAGS_MASK; + + if (copy_from_user(&xfa, ufa, sizeof(xfa))) + return -EFAULT; + + if (xfa.fsx_xflags & ~mask) + return -EOPNOTSUPP; + + fileattr_fill_xflags(fa, xfa.fsx_xflags & ~FS_XFLAG_RDONLY_MASK); + fa->fsx_extsize = xfa.fsx_extsize; + fa->fsx_nextents = xfa.fsx_nextents; + fa->fsx_projid = xfa.fsx_projid; + fa->fsx_cowextsize = xfa.fsx_cowextsize; + + return 0; +} + +/* + * Generic function to check FS_IOC_FSSETXATTR/FS_IOC_SETFLAGS values and reject + * any invalid configurations. + * + * Note: must be called with inode lock held. + */ +static int fileattr_set_prepare(struct inode *inode, + const struct file_kattr *old_ma, + struct file_kattr *fa) +{ + int err; + + /* + * The IMMUTABLE and APPEND_ONLY flags can only be changed by + * the relevant capability. + */ + if ((fa->flags ^ old_ma->flags) & (FS_APPEND_FL | FS_IMMUTABLE_FL) && + !capable(CAP_LINUX_IMMUTABLE)) + return -EPERM; + + err = fscrypt_prepare_setflags(inode, old_ma->flags, fa->flags); + if (err) + return err; + + /* + * Project Quota ID state is only allowed to change from within the init + * namespace. Enforce that restriction only if we are trying to change + * the quota ID state. Everything else is allowed in user namespaces. + */ + if (current_user_ns() != &init_user_ns) { + if (old_ma->fsx_projid != fa->fsx_projid) + return -EINVAL; + if ((old_ma->fsx_xflags ^ fa->fsx_xflags) & + FS_XFLAG_PROJINHERIT) + return -EINVAL; + } else { + /* + * Caller is allowed to change the project ID. If it is being + * changed, make sure that the new value is valid. + */ + if (old_ma->fsx_projid != fa->fsx_projid && + !projid_valid(make_kprojid(&init_user_ns, fa->fsx_projid))) + return -EINVAL; + } + + /* Check extent size hints. */ + if ((fa->fsx_xflags & FS_XFLAG_EXTSIZE) && !S_ISREG(inode->i_mode)) + return -EINVAL; + + if ((fa->fsx_xflags & FS_XFLAG_EXTSZINHERIT) && + !S_ISDIR(inode->i_mode)) + return -EINVAL; + + if ((fa->fsx_xflags & FS_XFLAG_COWEXTSIZE) && + !S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) + return -EINVAL; + + /* + * It is only valid to set the DAX flag on regular files and + * directories on filesystems. + */ + if ((fa->fsx_xflags & FS_XFLAG_DAX) && + !(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))) + return -EINVAL; + + /* Extent size hints of zero turn off the flags. */ + if (fa->fsx_extsize == 0) + fa->fsx_xflags &= ~(FS_XFLAG_EXTSIZE | FS_XFLAG_EXTSZINHERIT); + if (fa->fsx_cowextsize == 0) + fa->fsx_xflags &= ~FS_XFLAG_COWEXTSIZE; + + return 0; +} + +/** + * vfs_fileattr_set - change miscellaneous file attributes + * @idmap: idmap of the mount + * @dentry: the object to change + * @fa: fileattr pointer + * + * After verifying permissions, call i_op->fileattr_set() callback, if + * exists. + * + * Verifying attributes involves retrieving current attributes with + * i_op->fileattr_get(), this also allows initializing attributes that have + * not been set by the caller to current values. Inode lock is held + * thoughout to prevent racing with another instance. + * + * Return: 0 on success, or a negative error on failure. + */ +int vfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry, + struct file_kattr *fa) +{ + struct inode *inode = d_inode(dentry); + struct file_kattr old_ma = {}; + int err; + + if (!inode->i_op->fileattr_set) + return -ENOIOCTLCMD; + + if (!inode_owner_or_capable(idmap, inode)) + return -EPERM; + + inode_lock(inode); + err = vfs_fileattr_get(dentry, &old_ma); + if (!err) { + /* initialize missing bits from old_ma */ + if (fa->flags_valid) { + fa->fsx_xflags |= old_ma.fsx_xflags & ~FS_XFLAG_COMMON; + fa->fsx_extsize = old_ma.fsx_extsize; + fa->fsx_nextents = old_ma.fsx_nextents; + fa->fsx_projid = old_ma.fsx_projid; + fa->fsx_cowextsize = old_ma.fsx_cowextsize; + } else { + fa->flags |= old_ma.flags & ~FS_COMMON_FL; + } + + err = fileattr_set_prepare(inode, &old_ma, fa); + if (err) + goto out; + err = security_inode_file_setattr(dentry, fa); + if (err) + goto out; + err = inode->i_op->fileattr_set(idmap, dentry, fa); + if (err) + goto out; + fsnotify_xattr(dentry); + } + +out: + inode_unlock(inode); + return err; +} +EXPORT_SYMBOL(vfs_fileattr_set); + +int ioctl_getflags(struct file *file, unsigned int __user *argp) +{ + struct file_kattr fa = { .flags_valid = true }; /* hint only */ + int err; + + err = vfs_fileattr_get(file->f_path.dentry, &fa); + if (!err) + err = put_user(fa.flags, argp); + return err; +} + +int ioctl_setflags(struct file *file, unsigned int __user *argp) +{ + struct mnt_idmap *idmap = file_mnt_idmap(file); + struct dentry *dentry = file->f_path.dentry; + struct file_kattr fa = {}; + unsigned int flags; + int err; + + err = get_user(flags, argp); + if (!err) { + err = mnt_want_write_file(file); + if (!err) { + fileattr_fill_flags(&fa, flags); + err = vfs_fileattr_set(idmap, dentry, &fa); + mnt_drop_write_file(file); + } + } + return err; +} + +int ioctl_fsgetxattr(struct file *file, void __user *argp) +{ + struct file_kattr fa = { .fsx_valid = true }; /* hint only */ + int err; + + err = vfs_fileattr_get(file->f_path.dentry, &fa); + if (!err) + err = copy_fsxattr_to_user(&fa, argp); + + return err; +} + +int ioctl_fssetxattr(struct file *file, void __user *argp) +{ + struct mnt_idmap *idmap = file_mnt_idmap(file); + struct dentry *dentry = file->f_path.dentry; + struct file_kattr fa = {}; + int err; + + err = copy_fsxattr_from_user(&fa, argp); + if (!err) { + err = mnt_want_write_file(file); + if (!err) { + err = vfs_fileattr_set(idmap, dentry, &fa); + mnt_drop_write_file(file); + } + } + return err; +} + +SYSCALL_DEFINE5(file_getattr, int, dfd, const char __user *, filename, + struct file_attr __user *, ufattr, size_t, usize, + unsigned int, at_flags) +{ + struct path filepath __free(path_put) = {}; + unsigned int lookup_flags = 0; + struct file_attr fattr; + struct file_kattr fa = { .flags_valid = true }; /* hint only */ + int error; + + BUILD_BUG_ON(sizeof(struct file_attr) < FILE_ATTR_SIZE_VER0); + BUILD_BUG_ON(sizeof(struct file_attr) != FILE_ATTR_SIZE_LATEST); + + if ((at_flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) + return -EINVAL; + + if (!(at_flags & AT_SYMLINK_NOFOLLOW)) + lookup_flags |= LOOKUP_FOLLOW; + + if (usize > PAGE_SIZE) + return -E2BIG; + + if (usize < FILE_ATTR_SIZE_VER0) + return -EINVAL; + + CLASS(filename_maybe_null, name)(filename, at_flags); + if (!name && dfd >= 0) { + CLASS(fd, f)(dfd); + if (fd_empty(f)) + return -EBADF; + + filepath = fd_file(f)->f_path; + path_get(&filepath); + } else { + error = filename_lookup(dfd, name, lookup_flags, &filepath, + NULL); + if (error) + return error; + } + + error = vfs_fileattr_get(filepath.dentry, &fa); + if (error == -ENOIOCTLCMD || error == -ENOTTY) + error = -EOPNOTSUPP; + if (error) + return error; + + fileattr_to_file_attr(&fa, &fattr); + error = copy_struct_to_user(ufattr, usize, &fattr, + sizeof(struct file_attr), NULL); + + return error; +} + +SYSCALL_DEFINE5(file_setattr, int, dfd, const char __user *, filename, + struct file_attr __user *, ufattr, size_t, usize, + unsigned int, at_flags) +{ + struct path filepath __free(path_put) = {}; + unsigned int lookup_flags = 0; + struct file_attr fattr; + struct file_kattr fa = {}; + int error; + + BUILD_BUG_ON(sizeof(struct file_attr) < FILE_ATTR_SIZE_VER0); + BUILD_BUG_ON(sizeof(struct file_attr) != FILE_ATTR_SIZE_LATEST); + + if ((at_flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) + return -EINVAL; + + if (!(at_flags & AT_SYMLINK_NOFOLLOW)) + lookup_flags |= LOOKUP_FOLLOW; + + if (usize > PAGE_SIZE) + return -E2BIG; + + if (usize < FILE_ATTR_SIZE_VER0) + return -EINVAL; + + error = copy_struct_from_user(&fattr, sizeof(struct file_attr), ufattr, + usize); + if (error) + return error; + + error = file_attr_to_fileattr(&fattr, &fa); + if (error) + return error; + + CLASS(filename_maybe_null, name)(filename, at_flags); + if (!name && dfd >= 0) { + CLASS(fd, f)(dfd); + if (fd_empty(f)) + return -EBADF; + + filepath = fd_file(f)->f_path; + path_get(&filepath); + } else { + error = filename_lookup(dfd, name, lookup_flags, &filepath, + NULL); + if (error) + return error; + } + + error = mnt_want_write(filepath.mnt); + if (!error) { + error = vfs_fileattr_set(mnt_idmap(filepath.mnt), + filepath.dentry, &fa); + if (error == -ENOIOCTLCMD || error == -ENOTTY) + error = -EOPNOTSUPP; + mnt_drop_write(filepath.mnt); + } + + return error; +} -- cgit v1.3.1