diff options
Diffstat (limited to 'fs/statfs.c')
| -rw-r--r-- | fs/statfs.c | 193 |
1 files changed, 178 insertions, 15 deletions
diff --git a/fs/statfs.c b/fs/statfs.c index c219e733f553..a45ac85e6048 100644 --- a/fs/statfs.c +++ b/fs/statfs.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/syscalls.h> #include <linux/export.h> #include <linux/fs.h> @@ -7,6 +8,7 @@ #include <linux/statfs.h> #include <linux/security.h> #include <linux/uaccess.h> +#include <linux/compat.h> #include "internal.h" static int flags_by_mnt(int mnt_flags) @@ -27,16 +29,20 @@ static int flags_by_mnt(int mnt_flags) flags |= ST_NODIRATIME; if (mnt_flags & MNT_RELATIME) flags |= ST_RELATIME; + if (mnt_flags & MNT_NOSYMFOLLOW) + flags |= ST_NOSYMFOLLOW; return flags; } static int flags_by_sb(int s_flags) { int flags = 0; - if (s_flags & MS_SYNCHRONOUS) + if (s_flags & SB_SYNCHRONOUS) flags |= ST_SYNCHRONOUS; - if (s_flags & MS_MANDLOCK) + if (s_flags & SB_MANDLOCK) flags |= ST_MANDLOCK; + if (s_flags & SB_RDONLY) + flags |= ST_RDONLY; return flags; } @@ -63,7 +69,21 @@ static int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf) return retval; } -int vfs_statfs(struct path *path, struct kstatfs *buf) +int vfs_get_fsid(struct dentry *dentry, __kernel_fsid_t *fsid) +{ + struct kstatfs st; + int error; + + error = statfs_by_dentry(dentry, &st); + if (error) + return error; + + *fsid = st.f_fsid; + return 0; +} +EXPORT_SYMBOL(vfs_get_fsid); + +int vfs_statfs(const struct path *path, struct kstatfs *buf) { int error; @@ -94,13 +114,11 @@ retry: int fd_statfs(int fd, struct kstatfs *st) { - struct fd f = fdget(fd); - int error = -EBADF; - if (f.file) { - error = vfs_statfs(&f.file->f_path, st); - fdput(f); - } - return error; + CLASS(fd_raw, f)(fd); + + if (fd_empty(f)) + return -EBADF; + return vfs_statfs(&fd_file(f)->f_path, st); } static int do_statfs_native(struct kstatfs *st, struct statfs __user *p) @@ -110,6 +128,7 @@ static int do_statfs_native(struct kstatfs *st, struct statfs __user *p) if (sizeof(buf) == sizeof(*st)) memcpy(&buf, st, sizeof(*st)); else { + memset(&buf, 0, sizeof(buf)); if (sizeof buf.f_blocks == 4) { if ((st->f_blocks | st->f_bfree | st->f_bavail | st->f_bsize | st->f_frsize) & @@ -138,7 +157,6 @@ static int do_statfs_native(struct kstatfs *st, struct statfs __user *p) buf.f_namelen = st->f_namelen; buf.f_frsize = st->f_frsize; buf.f_flags = st->f_flags; - memset(buf.f_spare, 0, sizeof(buf.f_spare)); } if (copy_to_user(p, &buf, sizeof(buf))) return -EFAULT; @@ -151,6 +169,7 @@ static int do_statfs64(struct kstatfs *st, struct statfs64 __user *p) if (sizeof(buf) == sizeof(*st)) memcpy(&buf, st, sizeof(*st)); else { + memset(&buf, 0, sizeof(buf)); buf.f_type = st->f_type; buf.f_bsize = st->f_bsize; buf.f_blocks = st->f_blocks; @@ -162,7 +181,6 @@ static int do_statfs64(struct kstatfs *st, struct statfs64 __user *p) buf.f_namelen = st->f_namelen; buf.f_frsize = st->f_frsize; buf.f_flags = st->f_flags; - memset(buf.f_spare, 0, sizeof(buf.f_spare)); } if (copy_to_user(p, &buf, sizeof(buf))) return -EFAULT; @@ -213,9 +231,9 @@ SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user return error; } -int vfs_ustat(dev_t dev, struct kstatfs *sbuf) +static int vfs_ustat(dev_t dev, struct kstatfs *sbuf) { - struct super_block *s = user_get_super(dev); + struct super_block *s = user_get_super(dev, false); int err; if (!s) return -EINVAL; @@ -235,7 +253,152 @@ SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf) memset(&tmp,0,sizeof(struct ustat)); tmp.f_tfree = sbuf.f_bfree; - tmp.f_tinode = sbuf.f_ffree; + if (IS_ENABLED(CONFIG_ARCH_32BIT_USTAT_F_TINODE)) + tmp.f_tinode = min_t(u64, sbuf.f_ffree, UINT_MAX); + else + tmp.f_tinode = sbuf.f_ffree; return copy_to_user(ubuf, &tmp, sizeof(struct ustat)) ? -EFAULT : 0; } + +#ifdef CONFIG_COMPAT +static int put_compat_statfs(struct compat_statfs __user *ubuf, struct kstatfs *kbuf) +{ + struct compat_statfs buf; + if (sizeof ubuf->f_blocks == 4) { + if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail | + kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL) + return -EOVERFLOW; + /* f_files and f_ffree may be -1; it's okay + * to stuff that into 32 bits */ + if (kbuf->f_files != 0xffffffffffffffffULL + && (kbuf->f_files & 0xffffffff00000000ULL)) + return -EOVERFLOW; + if (kbuf->f_ffree != 0xffffffffffffffffULL + && (kbuf->f_ffree & 0xffffffff00000000ULL)) + return -EOVERFLOW; + } + memset(&buf, 0, sizeof(struct compat_statfs)); + buf.f_type = kbuf->f_type; + buf.f_bsize = kbuf->f_bsize; + buf.f_blocks = kbuf->f_blocks; + buf.f_bfree = kbuf->f_bfree; + buf.f_bavail = kbuf->f_bavail; + buf.f_files = kbuf->f_files; + buf.f_ffree = kbuf->f_ffree; + buf.f_namelen = kbuf->f_namelen; + buf.f_fsid.val[0] = kbuf->f_fsid.val[0]; + buf.f_fsid.val[1] = kbuf->f_fsid.val[1]; + buf.f_frsize = kbuf->f_frsize; + buf.f_flags = kbuf->f_flags; + if (copy_to_user(ubuf, &buf, sizeof(struct compat_statfs))) + return -EFAULT; + return 0; +} + +/* + * The following statfs calls are copies of code from fs/statfs.c and + * should be checked against those from time to time + */ +COMPAT_SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct compat_statfs __user *, buf) +{ + struct kstatfs tmp; + int error = user_statfs(pathname, &tmp); + if (!error) + error = put_compat_statfs(buf, &tmp); + return error; +} + +COMPAT_SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct compat_statfs __user *, buf) +{ + struct kstatfs tmp; + int error = fd_statfs(fd, &tmp); + if (!error) + error = put_compat_statfs(buf, &tmp); + return error; +} + +static int put_compat_statfs64(struct compat_statfs64 __user *ubuf, struct kstatfs *kbuf) +{ + struct compat_statfs64 buf; + + if ((kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL) + return -EOVERFLOW; + + memset(&buf, 0, sizeof(struct compat_statfs64)); + buf.f_type = kbuf->f_type; + buf.f_bsize = kbuf->f_bsize; + buf.f_blocks = kbuf->f_blocks; + buf.f_bfree = kbuf->f_bfree; + buf.f_bavail = kbuf->f_bavail; + buf.f_files = kbuf->f_files; + buf.f_ffree = kbuf->f_ffree; + buf.f_namelen = kbuf->f_namelen; + buf.f_fsid.val[0] = kbuf->f_fsid.val[0]; + buf.f_fsid.val[1] = kbuf->f_fsid.val[1]; + buf.f_frsize = kbuf->f_frsize; + buf.f_flags = kbuf->f_flags; + if (copy_to_user(ubuf, &buf, sizeof(struct compat_statfs64))) + return -EFAULT; + return 0; +} + +int kcompat_sys_statfs64(const char __user * pathname, compat_size_t sz, struct compat_statfs64 __user * buf) +{ + struct kstatfs tmp; + int error; + + if (sz != sizeof(*buf)) + return -EINVAL; + + error = user_statfs(pathname, &tmp); + if (!error) + error = put_compat_statfs64(buf, &tmp); + return error; +} + +COMPAT_SYSCALL_DEFINE3(statfs64, const char __user *, pathname, compat_size_t, sz, struct compat_statfs64 __user *, buf) +{ + return kcompat_sys_statfs64(pathname, sz, buf); +} + +int kcompat_sys_fstatfs64(unsigned int fd, compat_size_t sz, struct compat_statfs64 __user * buf) +{ + struct kstatfs tmp; + int error; + + if (sz != sizeof(*buf)) + return -EINVAL; + + error = fd_statfs(fd, &tmp); + if (!error) + error = put_compat_statfs64(buf, &tmp); + return error; +} + +COMPAT_SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, compat_size_t, sz, struct compat_statfs64 __user *, buf) +{ + return kcompat_sys_fstatfs64(fd, sz, buf); +} + +/* + * This is a copy of sys_ustat, just dealing with a structure layout. + * Given how simple this syscall is that apporach is more maintainable + * than the various conversion hacks. + */ +COMPAT_SYSCALL_DEFINE2(ustat, unsigned, dev, struct compat_ustat __user *, u) +{ + struct compat_ustat tmp; + struct kstatfs sbuf; + int err = vfs_ustat(new_decode_dev(dev), &sbuf); + if (err) + return err; + + memset(&tmp, 0, sizeof(struct compat_ustat)); + tmp.f_tfree = sbuf.f_bfree; + tmp.f_tinode = sbuf.f_ffree; + if (copy_to_user(u, &tmp, sizeof(struct compat_ustat))) + return -EFAULT; + return 0; +} +#endif |