// SPDX-License-Identifier: GPL-2.0/* * linux/fs/readdir.c * * Copyright (C) 1995 Linus Torvalds */ #include <linux/stddef.h>#include <linux/kernel.h>#include <linux/export.h>#include <linux/time.h>#include <linux/mm.h>#include <linux/errno.h>#include <linux/stat.h>#include <linux/file.h>#include <linux/fs.h>#include <linux/fsnotify.h>#include <linux/dirent.h>#include <linux/security.h>#include <linux/syscalls.h>#include <linux/unistd.h>#include <linux/compat.h>#include <linux/uaccess.h> #include <asm/unaligned.h> /* * Note the "unsafe_put_user() semantics: we goto a * label for errors. */#define unsafe_copy_dirent_name(_dst, _src, _len, label) do { \ char __user *dst = (_dst); \ const char *src = (_src); \ size_t len = (_len); \ unsafe_put_user(0, dst+len, label); \ unsafe_copy_to_user(dst, src, len, label); \} while (0) int iterate_dir(struct file *file, struct dir_context *ctx){ struct inode *inode = file_inode(file); bool shared = false; int res = -ENOTDIR; if (file->f_op->iterate_shared) shared = true; else if (!file->f_op->iterate) goto out; res = security_file_permission(file, MAY_READ); if (res) goto out; if (shared) res = down_read_killable(&inode->i_rwsem); else res = down_write_killable(&inode->i_rwsem); if (res) goto out; res = -ENOENT; if (!IS_DEADDIR(inode)) { ctx->pos = file->f_pos; if (shared) res = file->f_op->iterate_shared(file, ctx); else res = file->f_op->iterate(file, ctx); file->f_pos = ctx->pos; fsnotify_access(file); file_accessed(file); } if (shared) inode_unlock_shared(inode); else inode_unlock(inode);out: return res;}EXPORT_SYMBOL(iterate_dir); /* * POSIX says that a dirent name cannot contain NULL or a '/'. * * It's not 100% clear what we should really do in this case. * The filesystem is clearly corrupted, but returning a hard * error means that you now don't see any of the other names * either, so that isn't a perfect alternative. * * And if you return an error, what error do you use? Several * filesystems seem to have decided on EUCLEAN being the error * code for EFSCORRUPTED, and that may be the error to use. Or * just EIO, which is perhaps more obvious to users. * * In order to see the other file names in the directory, the * caller might want to make this a "soft" error: skip the * entry, and return the error at the end instead. * * Note that this should likely do a "memchr(name, 0, len)" * check too, since that would be filesystem corruption as * well. However, that case can't actually confuse user space, * which has to do a strlen() on the name anyway to find the * filename length, and the above "soft error" worry means * that it's probably better left alone until we have that * issue clarified. * * Note the PATH_MAX check - it's arbitrary but the real * kernel limit on a possible path component, not NAME_MAX, * which is the technical standard limit. */static int verify_dirent_name(const char *name, int len){ if (len <= 0 || len >= PATH_MAX) return -EIO; if (memchr(name, '/', len)) return -EIO; return 0;} /* * Traditional linux readdir() handling.. * * "count=1" is a special case, meaning that the buffer is one * dirent-structure in size and that the code can't handle more * anyway. Thus the special "fillonedir()" function for that * case (the low-level handlers don't need to care about this). */ #ifdef __ARCH_WANT_OLD_READDIR struct old_linux_dirent { unsigned long d_ino; unsigned long d_offset; unsigned short d_namlen; char d_name[1];}; struct readdir_callback { struct dir_context ctx; struct old_linux_dirent __user * dirent; int result;}; static int fillonedir(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type){ struct readdir_callback *buf = container_of(ctx, struct readdir_callback, ctx); struct old_linux_dirent __user * dirent; unsigned long d_ino; if (buf->result) return -EINVAL; buf->result = verify_dirent_name(name, namlen); if (buf->result < 0) return buf->result; d_ino = ino; if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { buf->result = -EOVERFLOW; return -EOVERFLOW; } buf->result++; dirent = buf->dirent; if (!user_write_access_begin(dirent, (unsigned long)(dirent->d_name + namlen + 1) - (unsigned long)dirent)) goto efault; unsafe_put_user(d_ino, &dirent->d_ino, efault_end); unsafe_put_user(offset, &dirent->d_offset, efault_end); unsafe_put_user(namlen, &dirent->d_namlen, efault_end); unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); user_write_access_end(); return 0;efault_end: user_write_access_end();efault: buf->result = -EFAULT; return -EFAULT;} SYSCALL_DEFINE3(old_readdir, unsigned int, fd, struct old_linux_dirent __user *, dirent, unsigned int, count){ int error; struct fd f = fdget_pos(fd); struct readdir_callback buf = { .ctx.actor = fillonedir, .dirent = dirent }; if (!f.file) return -EBADF; error = iterate_dir(f.file, &buf.ctx); if (buf.result) error = buf.result; fdput_pos(f); return error;} #endif /* __ARCH_WANT_OLD_READDIR */ /* * New, all-improved, singing, dancing, iBCS2-compliant getdents() * interface. */struct linux_dirent { unsigned long d_ino; unsigned long d_off; unsigned short d_reclen; char d_name[1];}; struct getdents_callback { struct dir_context ctx; struct linux_dirent __user * current_dir; int prev_reclen; int count; int error;}; static int filldir(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type){ struct linux_dirent __user *dirent, *prev; struct getdents_callback *buf = container_of(ctx, struct getdents_callback, ctx); unsigned long d_ino; int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2, sizeof(long)); int prev_reclen; buf->error = verify_dirent_name(name, namlen); if (unlikely(buf->error)) return buf->error; buf->error = -EINVAL; /* only used if we fail.. */ if (reclen > buf->count) return -EINVAL; d_ino = ino; if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { buf->error = -EOVERFLOW; return -EOVERFLOW; } prev_reclen = buf->prev_reclen; if (prev_reclen && signal_pending(current)) return -EINTR; dirent = buf->current_dir; prev = (void __user *) dirent - prev_reclen; if (!user_write_access_begin(prev, reclen + prev_reclen)) goto efault; /* This might be 'dirent->d_off', but if so it will get overwritten */ unsafe_put_user(offset, &prev->d_off, efault_end); unsafe_put_user(d_ino, &dirent->d_ino, efault_end); unsafe_put_user(reclen, &dirent->d_reclen, efault_end); unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end); unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); user_write_access_end(); buf->current_dir = (void __user *)dirent + reclen; buf->prev_reclen = reclen; buf->count -= reclen; return 0;efault_end: user_write_access_end();efault: buf->error = -EFAULT; return -EFAULT;} SYSCALL_DEFINE3(getdents, unsigned int, fd, struct linux_dirent __user *, dirent, unsigned int, count){ struct fd f; struct getdents_callback buf = { .ctx.actor = filldir, .count = count, .current_dir = dirent }; int error; f = fdget_pos(fd); if (!f.file) return -EBADF; error = iterate_dir(f.file, &buf.ctx); if (error >= 0) error = buf.error; if (buf.prev_reclen) { struct linux_dirent __user * lastdirent; lastdirent = (void __user *)buf.current_dir - buf.prev_reclen; if (put_user(buf.ctx.pos, &lastdirent->d_off)) error = -EFAULT; else error = count - buf.count; } fdput_pos(f); return error;} struct getdents_callback64 { struct dir_context ctx; struct linux_dirent64 __user * current_dir; int prev_reclen; int count; int error;}; static int filldir64(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type){ struct linux_dirent64 __user *dirent, *prev; struct getdents_callback64 *buf = container_of(ctx, struct getdents_callback64, ctx); int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1, sizeof(u64)); int prev_reclen; buf->error = verify_dirent_name(name, namlen); if (unlikely(buf->error)) return buf->error; buf->error = -EINVAL; /* only used if we fail.. */ if (reclen > buf->count) return -EINVAL; prev_reclen = buf->prev_reclen; if (prev_reclen && signal_pending(current)) return -EINTR; dirent = buf->current_dir; prev = (void __user *)dirent - prev_reclen; if (!user_write_access_begin(prev, reclen + prev_reclen)) goto efault; /* This might be 'dirent->d_off', but if so it will get overwritten */ unsafe_put_user(offset, &prev->d_off, efault_end); unsafe_put_user(ino, &dirent->d_ino, efault_end); unsafe_put_user(reclen, &dirent->d_reclen, efault_end); unsafe_put_user(d_type, &dirent->d_type, efault_end); unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); user_write_access_end(); buf->prev_reclen = reclen; buf->current_dir = (void __user *)dirent + reclen; buf->count -= reclen; return 0; efault_end: user_write_access_end();efault: buf->error = -EFAULT; return -EFAULT;} SYSCALL_DEFINE3(getdents64, unsigned int, fd, struct linux_dirent64 __user *, dirent, unsigned int, count){ struct fd f; struct getdents_callback64 buf = { .ctx.actor = filldir64, .count = count, .current_dir = dirent }; int error; f = fdget_pos(fd); if (!f.file) return -EBADF; error = iterate_dir(f.file, &buf.ctx); if (error >= 0) error = buf.error; if (buf.prev_reclen) { struct linux_dirent64 __user * lastdirent; typeof(lastdirent->d_off) d_off = buf.ctx.pos; lastdirent = (void __user *) buf.current_dir - buf.prev_reclen; if (put_user(d_off, &lastdirent->d_off)) error = -EFAULT; else error = count - buf.count; } fdput_pos(f); return error;} #ifdef CONFIG_COMPATstruct compat_old_linux_dirent { compat_ulong_t d_ino; compat_ulong_t d_offset; unsigned short d_namlen; char d_name[1];}; struct compat_readdir_callback { struct dir_context ctx; struct compat_old_linux_dirent __user *dirent; int result;}; static int compat_fillonedir(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type){ struct compat_readdir_callback *buf = container_of(ctx, struct compat_readdir_callback, ctx); struct compat_old_linux_dirent __user *dirent; compat_ulong_t d_ino; if (buf->result) return -EINVAL; buf->result = verify_dirent_name(name, namlen); if (buf->result < 0) return buf->result; d_ino = ino; if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { buf->result = -EOVERFLOW; return -EOVERFLOW; } buf->result++; dirent = buf->dirent; if (!user_write_access_begin(dirent, (unsigned long)(dirent->d_name + namlen + 1) - (unsigned long)dirent)) goto efault; unsafe_put_user(d_ino, &dirent->d_ino, efault_end); unsafe_put_user(offset, &dirent->d_offset, efault_end); unsafe_put_user(namlen, &dirent->d_namlen, efault_end); unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); user_write_access_end(); return 0;efault_end: user_write_access_end();efault: buf->result = -EFAULT; return -EFAULT;} COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd, struct compat_old_linux_dirent __user *, dirent, unsigned int, count){ int error; struct fd f = fdget_pos(fd); struct compat_readdir_callback buf = { .ctx.actor = compat_fillonedir, .dirent = dirent }; if (!f.file) return -EBADF; error = iterate_dir(f.file, &buf.ctx); if (buf.result) error = buf.result; fdput_pos(f); return error;} struct compat_linux_dirent { compat_ulong_t d_ino; compat_ulong_t d_off; unsigned short d_reclen; char d_name[1];}; struct compat_getdents_callback { struct dir_context ctx; struct compat_linux_dirent __user *current_dir; int prev_reclen; int count; int error;}; static int compat_filldir(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type){ struct compat_linux_dirent __user *dirent, *prev; struct compat_getdents_callback *buf = container_of(ctx, struct compat_getdents_callback, ctx); compat_ulong_t d_ino; int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) + namlen + 2, sizeof(compat_long_t)); int prev_reclen; buf->error = verify_dirent_name(name, namlen); if (unlikely(buf->error)) return buf->error; buf->error = -EINVAL; /* only used if we fail.. */ if (reclen > buf->count) return -EINVAL; d_ino = ino; if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { buf->error = -EOVERFLOW; return -EOVERFLOW; } prev_reclen = buf->prev_reclen; if (prev_reclen && signal_pending(current)) return -EINTR; dirent = buf->current_dir; prev = (void __user *) dirent - prev_reclen;Lines 1–500 of 552. Load more
// SPDX-License-Identifier: GPL-2.0 /* * linux/fs/readdir.c * * Copyright (C) 1995 Linus Torvalds */ #include <linux/stddef.h> #include <linux/kernel.h> #include <linux/export.h> #include <linux/time.h> #include <linux/mm.h> #include <linux/errno.h> #include <linux/stat.h> #include <linux/file.h> #include <linux/fs.h> #include <linux/fsnotify.h> #include <linux/dirent.h> #include <linux/security.h> #include <linux/syscalls.h> #include <linux/unistd.h> #include <linux/compat.h> #include <linux/uaccess.h> #include <asm/unaligned.h> /* * Note the "unsafe_put_user() semantics: we goto a * label for errors. */ #define unsafe_copy_dirent_name(_dst, _src, _len, label) do { \ char __user *dst = (_dst); \ const char *src = (_src); \ size_t len = (_len); \ unsafe_put_user(0, dst+len, label); \ unsafe_copy_to_user(dst, src, len, label); \ } while (0) int iterate_dir(struct file *file, struct dir_context *ctx) { struct inode *inode = file_inode(file); bool shared = false; int res = -ENOTDIR; if (file->f_op->iterate_shared) shared = true; else if (!file->f_op->iterate) goto out; res = security_file_permission(file, MAY_READ); if (res) goto out; if (shared) res = down_read_killable(&inode->i_rwsem); else res = down_write_killable(&inode->i_rwsem); if (res) goto out; res = -ENOENT; if (!IS_DEADDIR(inode)) { ctx->pos = file->f_pos; if (shared) res = file->f_op->iterate_shared(file, ctx); else res = file->f_op->iterate(file, ctx); file->f_pos = ctx->pos; fsnotify_access(file); file_accessed(file); } if (shared) inode_unlock_shared(inode); else inode_unlock(inode); out: return res; } EXPORT_SYMBOL(iterate_dir); /* * POSIX says that a dirent name cannot contain NULL or a '/'. * * It's not 100% clear what we should really do in this case. * The filesystem is clearly corrupted, but returning a hard * error means that you now don't see any of the other names * either, so that isn't a perfect alternative. * * And if you return an error, what error do you use? Several * filesystems seem to have decided on EUCLEAN being the error * code for EFSCORRUPTED, and that may be the error to use. Or * just EIO, which is perhaps more obvious to users. * * In order to see the other file names in the directory, the * caller might want to make this a "soft" error: skip the * entry, and return the error at the end instead. * * Note that this should likely do a "memchr(name, 0, len)" * check too, since that would be filesystem corruption as * well. However, that case can't actually confuse user space, * which has to do a strlen() on the name anyway to find the * filename length, and the above "soft error" worry means * that it's probably better left alone until we have that * issue clarified. * * Note the PATH_MAX check - it's arbitrary but the real * kernel limit on a possible path component, not NAME_MAX, * which is the technical standard limit. */ static int verify_dirent_name(const char *name, int len) { if (len <= 0 || len >= PATH_MAX) return -EIO; if (memchr(name, '/', len)) return -EIO; return 0; } /* * Traditional linux readdir() handling.. * * "count=1" is a special case, meaning that the buffer is one * dirent-structure in size and that the code can't handle more * anyway. Thus the special "fillonedir()" function for that * case (the low-level handlers don't need to care about this). */ #ifdef __ARCH_WANT_OLD_READDIR struct old_linux_dirent { unsigned long d_ino; unsigned long d_offset; unsigned short d_namlen; char d_name[1]; }; struct readdir_callback { struct dir_context ctx; struct old_linux_dirent __user * dirent; int result; }; static int fillonedir(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct readdir_callback *buf = container_of(ctx, struct readdir_callback, ctx); struct old_linux_dirent __user * dirent; unsigned long d_ino; if (buf->result) return -EINVAL; buf->result = verify_dirent_name(name, namlen); if (buf->result < 0) return buf->result; d_ino = ino; if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { buf->result = -EOVERFLOW; return -EOVERFLOW; } buf->result++; dirent = buf->dirent; if (!user_write_access_begin(dirent, (unsigned long)(dirent->d_name + namlen + 1) - (unsigned long)dirent)) goto efault; unsafe_put_user(d_ino, &dirent->d_ino, efault_end); unsafe_put_user(offset, &dirent->d_offset, efault_end); unsafe_put_user(namlen, &dirent->d_namlen, efault_end); unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); user_write_access_end(); return 0; efault_end: user_write_access_end(); efault: buf->result = -EFAULT; return -EFAULT; } SYSCALL_DEFINE3(old_readdir, unsigned int, fd, struct old_linux_dirent __user *, dirent, unsigned int, count) { int error; struct fd f = fdget_pos(fd); struct readdir_callback buf = { .ctx.actor = fillonedir, .dirent = dirent }; if (!f.file) return -EBADF; error = iterate_dir(f.file, &buf.ctx); if (buf.result) error = buf.result; fdput_pos(f); return error; } #endif /* __ARCH_WANT_OLD_READDIR */ /* * New, all-improved, singing, dancing, iBCS2-compliant getdents() * interface. */ struct linux_dirent { unsigned long d_ino; unsigned long d_off; unsigned short d_reclen; char d_name[1]; }; struct getdents_callback { struct dir_context ctx; struct linux_dirent __user * current_dir; int prev_reclen; int count; int error; }; static int filldir(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct linux_dirent __user *dirent, *prev; struct getdents_callback *buf = container_of(ctx, struct getdents_callback, ctx); unsigned long d_ino; int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2, sizeof(long)); int prev_reclen; buf->error = verify_dirent_name(name, namlen); if (unlikely(buf->error)) return buf->error; buf->error = -EINVAL; /* only used if we fail.. */ if (reclen > buf->count) return -EINVAL; d_ino = ino; if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { buf->error = -EOVERFLOW; return -EOVERFLOW; } prev_reclen = buf->prev_reclen; if (prev_reclen && signal_pending(current)) return -EINTR; dirent = buf->current_dir; prev = (void __user *) dirent - prev_reclen; if (!user_write_access_begin(prev, reclen + prev_reclen)) goto efault; /* This might be 'dirent->d_off', but if so it will get overwritten */ unsafe_put_user(offset, &prev->d_off, efault_end); unsafe_put_user(d_ino, &dirent->d_ino, efault_end); unsafe_put_user(reclen, &dirent->d_reclen, efault_end); unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end); unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); user_write_access_end(); buf->current_dir = (void __user *)dirent + reclen; buf->prev_reclen = reclen; buf->count -= reclen; return 0; efault_end: user_write_access_end(); efault: buf->error = -EFAULT; return -EFAULT; } SYSCALL_DEFINE3(getdents, unsigned int, fd, struct linux_dirent __user *, dirent, unsigned int, count) { struct fd f; struct getdents_callback buf = { .ctx.actor = filldir, .count = count, .current_dir = dirent }; int error; f = fdget_pos(fd); if (!f.file) return -EBADF; error = iterate_dir(f.file, &buf.ctx); if (error >= 0) error = buf.error; if (buf.prev_reclen) { struct linux_dirent __user * lastdirent; lastdirent = (void __user *)buf.current_dir - buf.prev_reclen; if (put_user(buf.ctx.pos, &lastdirent->d_off)) error = -EFAULT; else error = count - buf.count; } fdput_pos(f); return error; } struct getdents_callback64 { struct dir_context ctx; struct linux_dirent64 __user * current_dir; int prev_reclen; int count; int error; }; static int filldir64(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct linux_dirent64 __user *dirent, *prev; struct getdents_callback64 *buf = container_of(ctx, struct getdents_callback64, ctx); int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1, sizeof(u64)); int prev_reclen; buf->error = verify_dirent_name(name, namlen); if (unlikely(buf->error)) return buf->error; buf->error = -EINVAL; /* only used if we fail.. */ if (reclen > buf->count) return -EINVAL; prev_reclen = buf->prev_reclen; if (prev_reclen && signal_pending(current)) return -EINTR; dirent = buf->current_dir; prev = (void __user *)dirent - prev_reclen; if (!user_write_access_begin(prev, reclen + prev_reclen)) goto efault; /* This might be 'dirent->d_off', but if so it will get overwritten */ unsafe_put_user(offset, &prev->d_off, efault_end); unsafe_put_user(ino, &dirent->d_ino, efault_end); unsafe_put_user(reclen, &dirent->d_reclen, efault_end); unsafe_put_user(d_type, &dirent->d_type, efault_end); unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); user_write_access_end(); buf->prev_reclen = reclen; buf->current_dir = (void __user *)dirent + reclen; buf->count -= reclen; return 0; efault_end: user_write_access_end(); efault: buf->error = -EFAULT; return -EFAULT; } SYSCALL_DEFINE3(getdents64, unsigned int, fd, struct linux_dirent64 __user *, dirent, unsigned int, count) { struct fd f; struct getdents_callback64 buf = { .ctx.actor = filldir64, .count = count, .current_dir = dirent }; int error; f = fdget_pos(fd); if (!f.file) return -EBADF; error = iterate_dir(f.file, &buf.ctx); if (error >= 0) error = buf.error; if (buf.prev_reclen) { struct linux_dirent64 __user * lastdirent; typeof(lastdirent->d_off) d_off = buf.ctx.pos; lastdirent = (void __user *) buf.current_dir - buf.prev_reclen; if (put_user(d_off, &lastdirent->d_off)) error = -EFAULT; else error = count - buf.count; } fdput_pos(f); return error; } #ifdef CONFIG_COMPAT struct compat_old_linux_dirent { compat_ulong_t d_ino; compat_ulong_t d_offset; unsigned short d_namlen; char d_name[1]; }; struct compat_readdir_callback { struct dir_context ctx; struct compat_old_linux_dirent __user *dirent; int result; }; static int compat_fillonedir(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct compat_readdir_callback *buf = container_of(ctx, struct compat_readdir_callback, ctx); struct compat_old_linux_dirent __user *dirent; compat_ulong_t d_ino; if (buf->result) return -EINVAL; buf->result = verify_dirent_name(name, namlen); if (buf->result < 0) return buf->result; d_ino = ino; if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { buf->result = -EOVERFLOW; return -EOVERFLOW; } buf->result++; dirent = buf->dirent; if (!user_write_access_begin(dirent, (unsigned long)(dirent->d_name + namlen + 1) - (unsigned long)dirent)) goto efault; unsafe_put_user(d_ino, &dirent->d_ino, efault_end); unsafe_put_user(offset, &dirent->d_offset, efault_end); unsafe_put_user(namlen, &dirent->d_namlen, efault_end); unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); user_write_access_end(); return 0; efault_end: user_write_access_end(); efault: buf->result = -EFAULT; return -EFAULT; } COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd, struct compat_old_linux_dirent __user *, dirent, unsigned int, count) { int error; struct fd f = fdget_pos(fd); struct compat_readdir_callback buf = { .ctx.actor = compat_fillonedir, .dirent = dirent }; if (!f.file) return -EBADF; error = iterate_dir(f.file, &buf.ctx); if (buf.result) error = buf.result; fdput_pos(f); return error; } struct compat_linux_dirent { compat_ulong_t d_ino; compat_ulong_t d_off; unsigned short d_reclen; char d_name[1]; }; struct compat_getdents_callback { struct dir_context ctx; struct compat_linux_dirent __user *current_dir; int prev_reclen; int count; int error; }; static int compat_filldir(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct compat_linux_dirent __user *dirent, *prev; struct compat_getdents_callback *buf = container_of(ctx, struct compat_getdents_callback, ctx); compat_ulong_t d_ino; int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) + namlen + 2, sizeof(compat_long_t)); int prev_reclen; buf->error = verify_dirent_name(name, namlen); if (unlikely(buf->error)) return buf->error; buf->error = -EINVAL; /* only used if we fail.. */ if (reclen > buf->count) return -EINVAL; d_ino = ino; if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { buf->error = -EOVERFLOW; return -EOVERFLOW; } prev_reclen = buf->prev_reclen; if (prev_reclen && signal_pending(current)) return -EINTR; dirent = buf->current_dir; prev = (void __user *) dirent - prev_reclen;