linux-stable/fs/ioctl.c
Alfred Piccioni f1bb47a31d lsm: new security_file_ioctl_compat() hook
Some ioctl commands do not require ioctl permission, but are routed to
other permissions such as FILE_GETATTR or FILE_SETATTR. This routing is
done by comparing the ioctl cmd to a set of 64-bit flags (FS_IOC_*).

However, if a 32-bit process is running on a 64-bit kernel, it emits
32-bit flags (FS_IOC32_*) for certain ioctl operations. These flags are
being checked erroneously, which leads to these ioctl operations being
routed to the ioctl permission, rather than the correct file
permissions.

This was also noted in a RED-PEN finding from a while back -
"/* RED-PEN how should LSM module know it's handling 32bit? */".

This patch introduces a new hook, security_file_ioctl_compat(), that is
called from the compat ioctl syscall. All current LSMs have been changed
to support this hook.

Reviewing the three places where we are currently using
security_file_ioctl(), it appears that only SELinux needs a dedicated
compat change; TOMOYO and SMACK appear to be functional without any
change.

Cc: stable@vger.kernel.org
Fixes: 0b24dcb7f2 ("Revert "selinux: simplify ioctl checking"")
Signed-off-by: Alfred Piccioni <alpic@google.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: subject tweak, line length fixes, and alignment corrections]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-24 15:48:03 -05:00

982 lines
24 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/ioctl.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#include <linux/syscalls.h>
#include <linux/mm.h>
#include <linux/capability.h>
#include <linux/compat.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/security.h>
#include <linux/export.h>
#include <linux/uaccess.h>
#include <linux/writeback.h>
#include <linux/buffer_head.h>
#include <linux/falloc.h>
#include <linux/sched/signal.h>
#include <linux/fiemap.h>
#include <linux/mount.h>
#include <linux/fscrypt.h>
#include <linux/fileattr.h>
#include "internal.h"
#include <asm/ioctls.h>
/* So that the fiemap access checks can't overflow on 32 bit machines. */
#define FIEMAP_MAX_EXTENTS (UINT_MAX / sizeof(struct fiemap_extent))
/**
* vfs_ioctl - call filesystem specific ioctl methods
* @filp: open file to invoke ioctl method on
* @cmd: ioctl command to execute
* @arg: command-specific argument for ioctl
*
* Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise
* returns -ENOTTY.
*
* Returns 0 on success, -errno on error.
*/
long vfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
int error = -ENOTTY;
if (!filp->f_op->unlocked_ioctl)
goto out;
error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
if (error == -ENOIOCTLCMD)
error = -ENOTTY;
out:
return error;
}
EXPORT_SYMBOL(vfs_ioctl);
static int ioctl_fibmap(struct file *filp, int __user *p)
{
struct inode *inode = file_inode(filp);
struct super_block *sb = inode->i_sb;
int error, ur_block;
sector_t block;
if (!capable(CAP_SYS_RAWIO))
return -EPERM;
error = get_user(ur_block, p);
if (error)
return error;
if (ur_block < 0)
return -EINVAL;
block = ur_block;
error = bmap(inode, &block);
if (block > INT_MAX) {
error = -ERANGE;
pr_warn_ratelimited("[%s/%d] FS: %s File: %pD4 would truncate fibmap result\n",
current->comm, task_pid_nr(current),
sb->s_id, filp);
}
if (error)
ur_block = 0;
else
ur_block = block;
if (put_user(ur_block, p))
error = -EFAULT;
return error;
}
/**
* fiemap_fill_next_extent - Fiemap helper function
* @fieinfo: Fiemap context passed into ->fiemap
* @logical: Extent logical start offset, in bytes
* @phys: Extent physical start offset, in bytes
* @len: Extent length, in bytes
* @flags: FIEMAP_EXTENT flags that describe this extent
*
* Called from file system ->fiemap callback. Will populate extent
* info as passed in via arguments and copy to user memory. On
* success, extent count on fieinfo is incremented.
*
* Returns 0 on success, -errno on error, 1 if this was the last
* extent that will fit in user array.
*/
int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
u64 phys, u64 len, u32 flags)
{
struct fiemap_extent extent;
struct fiemap_extent __user *dest = fieinfo->fi_extents_start;
/* only count the extents */
if (fieinfo->fi_extents_max == 0) {
fieinfo->fi_extents_mapped++;
return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
}
if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
return 1;
#define SET_UNKNOWN_FLAGS (FIEMAP_EXTENT_DELALLOC)
#define SET_NO_UNMOUNTED_IO_FLAGS (FIEMAP_EXTENT_DATA_ENCRYPTED)
#define SET_NOT_ALIGNED_FLAGS (FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
if (flags & SET_UNKNOWN_FLAGS)
flags |= FIEMAP_EXTENT_UNKNOWN;
if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
flags |= FIEMAP_EXTENT_ENCODED;
if (flags & SET_NOT_ALIGNED_FLAGS)
flags |= FIEMAP_EXTENT_NOT_ALIGNED;
memset(&extent, 0, sizeof(extent));
extent.fe_logical = logical;
extent.fe_physical = phys;
extent.fe_length = len;
extent.fe_flags = flags;
dest += fieinfo->fi_extents_mapped;
if (copy_to_user(dest, &extent, sizeof(extent)))
return -EFAULT;
fieinfo->fi_extents_mapped++;
if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
return 1;
return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
}
EXPORT_SYMBOL(fiemap_fill_next_extent);
/**
* fiemap_prep - check validity of requested flags for fiemap
* @inode: Inode to operate on
* @fieinfo: Fiemap context passed into ->fiemap
* @start: Start of the mapped range
* @len: Length of the mapped range, can be truncated by this function.
* @supported_flags: Set of fiemap flags that the file system understands
*
* This function must be called from each ->fiemap instance to validate the
* fiemap request against the file system parameters.
*
* Returns 0 on success, or a negative error on failure.
*/
int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo,
u64 start, u64 *len, u32 supported_flags)
{
u64 maxbytes = inode->i_sb->s_maxbytes;
u32 incompat_flags;
int ret = 0;
if (*len == 0)
return -EINVAL;
if (start >= maxbytes)
return -EFBIG;
/*
* Shrink request scope to what the fs can actually handle.
*/
if (*len > maxbytes || (maxbytes - *len) < start)
*len = maxbytes - start;
supported_flags |= FIEMAP_FLAG_SYNC;
supported_flags &= FIEMAP_FLAGS_COMPAT;
incompat_flags = fieinfo->fi_flags & ~supported_flags;
if (incompat_flags) {
fieinfo->fi_flags = incompat_flags;
return -EBADR;
}
if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
ret = filemap_write_and_wait(inode->i_mapping);
return ret;
}
EXPORT_SYMBOL(fiemap_prep);
static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap)
{
struct fiemap fiemap;
struct fiemap_extent_info fieinfo = { 0, };
struct inode *inode = file_inode(filp);
int error;
if (!inode->i_op->fiemap)
return -EOPNOTSUPP;
if (copy_from_user(&fiemap, ufiemap, sizeof(fiemap)))
return -EFAULT;
if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
return -EINVAL;
fieinfo.fi_flags = fiemap.fm_flags;
fieinfo.fi_extents_max = fiemap.fm_extent_count;
fieinfo.fi_extents_start = ufiemap->fm_extents;
error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start,
fiemap.fm_length);
fiemap.fm_flags = fieinfo.fi_flags;
fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
error = -EFAULT;
return error;
}
static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
u64 off, u64 olen, u64 destoff)
{
struct fd src_file = fdget(srcfd);
loff_t cloned;
int ret;
if (!src_file.file)
return -EBADF;
cloned = vfs_clone_file_range(src_file.file, off, dst_file, destoff,
olen, 0);
if (cloned < 0)
ret = cloned;
else if (olen && cloned != olen)
ret = -EINVAL;
else
ret = 0;
fdput(src_file);
return ret;
}
static long ioctl_file_clone_range(struct file *file,
struct file_clone_range __user *argp)
{
struct file_clone_range args;
if (copy_from_user(&args, argp, sizeof(args)))
return -EFAULT;
return ioctl_file_clone(file, args.src_fd, args.src_offset,
args.src_length, args.dest_offset);
}
/*
* This provides compatibility with legacy XFS pre-allocation ioctls
* which predate the fallocate syscall.
*
* Only the l_start, l_len and l_whence fields of the 'struct space_resv'
* are used here, rest are ignored.
*/
static int ioctl_preallocate(struct file *filp, int mode, void __user *argp)
{
struct inode *inode = file_inode(filp);
struct space_resv sr;
if (copy_from_user(&sr, argp, sizeof(sr)))
return -EFAULT;
switch (sr.l_whence) {
case SEEK_SET:
break;
case SEEK_CUR:
sr.l_start += filp->f_pos;
break;
case SEEK_END:
sr.l_start += i_size_read(inode);
break;
default:
return -EINVAL;
}
return vfs_fallocate(filp, mode | FALLOC_FL_KEEP_SIZE, sr.l_start,
sr.l_len);
}
/* on ia32 l_start is on a 32-bit boundary */
#if defined CONFIG_COMPAT && defined(CONFIG_X86_64)
/* just account for different alignment */
static int compat_ioctl_preallocate(struct file *file, int mode,
struct space_resv_32 __user *argp)
{
struct inode *inode = file_inode(file);
struct space_resv_32 sr;
if (copy_from_user(&sr, argp, sizeof(sr)))
return -EFAULT;
switch (sr.l_whence) {
case SEEK_SET:
break;
case SEEK_CUR:
sr.l_start += file->f_pos;
break;
case SEEK_END:
sr.l_start += i_size_read(inode);
break;
default:
return -EINVAL;
}
return vfs_fallocate(file, mode | FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
}
#endif
static int file_ioctl(struct file *filp, unsigned int cmd, int __user *p)
{
switch (cmd) {
case FIBMAP:
return ioctl_fibmap(filp, p);
case FS_IOC_RESVSP:
case FS_IOC_RESVSP64:
return ioctl_preallocate(filp, 0, p);
case FS_IOC_UNRESVSP:
case FS_IOC_UNRESVSP64:
return ioctl_preallocate(filp, FALLOC_FL_PUNCH_HOLE, p);
case FS_IOC_ZERO_RANGE:
return ioctl_preallocate(filp, FALLOC_FL_ZERO_RANGE, p);
}
return -ENOIOCTLCMD;
}
static int ioctl_fionbio(struct file *filp, int __user *argp)
{
unsigned int flag;
int on, error;
error = get_user(on, argp);
if (error)
return error;
flag = O_NONBLOCK;
#ifdef __sparc__
/* SunOS compatibility item. */
if (O_NONBLOCK != O_NDELAY)
flag |= O_NDELAY;
#endif
spin_lock(&filp->f_lock);
if (on)
filp->f_flags |= flag;
else
filp->f_flags &= ~flag;
spin_unlock(&filp->f_lock);
return error;
}
static int ioctl_fioasync(unsigned int fd, struct file *filp,
int __user *argp)
{
unsigned int flag;
int on, error;
error = get_user(on, argp);
if (error)
return error;
flag = on ? FASYNC : 0;
/* Did FASYNC state change ? */
if ((flag ^ filp->f_flags) & FASYNC) {
if (filp->f_op->fasync)
/* fasync() adjusts filp->f_flags */
error = filp->f_op->fasync(fd, filp, on);
else
error = -ENOTTY;
}
return error < 0 ? error : 0;
}
static int ioctl_fsfreeze(struct file *filp)
{
struct super_block *sb = file_inode(filp)->i_sb;
if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
return -EPERM;
/* If filesystem doesn't support freeze feature, return. */
if (sb->s_op->freeze_fs == NULL && sb->s_op->freeze_super == NULL)
return -EOPNOTSUPP;
/* Freeze */
if (sb->s_op->freeze_super)
return sb->s_op->freeze_super(sb, FREEZE_HOLDER_USERSPACE);
return freeze_super(sb, FREEZE_HOLDER_USERSPACE);
}
static int ioctl_fsthaw(struct file *filp)
{
struct super_block *sb = file_inode(filp)->i_sb;
if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
return -EPERM;
/* Thaw */
if (sb->s_op->thaw_super)
return sb->s_op->thaw_super(sb, FREEZE_HOLDER_USERSPACE);
return thaw_super(sb, FREEZE_HOLDER_USERSPACE);
}
static int ioctl_file_dedupe_range(struct file *file,
struct file_dedupe_range __user *argp)
{
struct file_dedupe_range *same = NULL;
int ret;
unsigned long size;
u16 count;
if (get_user(count, &argp->dest_count)) {
ret = -EFAULT;
goto out;
}
size = offsetof(struct file_dedupe_range, info[count]);
if (size > PAGE_SIZE) {
ret = -ENOMEM;
goto out;
}
same = memdup_user(argp, size);
if (IS_ERR(same)) {
ret = PTR_ERR(same);
same = NULL;
goto out;
}
same->dest_count = count;
ret = vfs_dedupe_file_range(file, same);
if (ret)
goto out;
ret = copy_to_user(argp, same, size);
if (ret)
ret = -EFAULT;
out:
kfree(same);
return ret;
}
/**
* fileattr_fill_xflags - initialize fileattr with xflags
* @fa: fileattr pointer
* @xflags: FS_XFLAG_* flags
*
* Set ->fsx_xflags, ->fsx_valid and ->flags (translated xflags). All
* other fields are zeroed.
*/
void fileattr_fill_xflags(struct fileattr *fa, u32 xflags)
{
memset(fa, 0, sizeof(*fa));
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;
}
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).
* All other fields are zeroed.
*/
void fileattr_fill_flags(struct fileattr *fa, u32 flags)
{
memset(fa, 0, sizeof(*fa));
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;
}
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 fileattr *fa)
{
struct inode *inode = d_inode(dentry);
if (!inode->i_op->fileattr_get)
return -ENOIOCTLCMD;
return inode->i_op->fileattr_get(dentry, fa);
}
EXPORT_SYMBOL(vfs_fileattr_get);
/**
* 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 fileattr *fa, struct fsxattr __user *ufa)
{
struct fsxattr xfa;
memset(&xfa, 0, sizeof(xfa));
xfa.fsx_xflags = fa->fsx_xflags;
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 copy_fsxattr_from_user(struct fileattr *fa,
struct fsxattr __user *ufa)
{
struct fsxattr xfa;
if (copy_from_user(&xfa, ufa, sizeof(xfa)))
return -EFAULT;
fileattr_fill_xflags(fa, xfa.fsx_xflags);
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 fileattr *old_ma,
struct fileattr *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 fileattr *fa)
{
struct inode *inode = d_inode(dentry);
struct fileattr 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)
err = inode->i_op->fileattr_set(idmap, dentry, fa);
}
inode_unlock(inode);
return err;
}
EXPORT_SYMBOL(vfs_fileattr_set);
static int ioctl_getflags(struct file *file, unsigned int __user *argp)
{
struct fileattr 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;
}
static 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 fileattr 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;
}
static int ioctl_fsgetxattr(struct file *file, void __user *argp)
{
struct fileattr 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;
}
static 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 fileattr 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;
}
/*
* do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
* It's just a simple helper for sys_ioctl and compat_sys_ioctl.
*
* When you add any new common ioctls to the switches above and below,
* please ensure they have compatible arguments in compat mode.
*/
static int do_vfs_ioctl(struct file *filp, unsigned int fd,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
struct inode *inode = file_inode(filp);
switch (cmd) {
case FIOCLEX:
set_close_on_exec(fd, 1);
return 0;
case FIONCLEX:
set_close_on_exec(fd, 0);
return 0;
case FIONBIO:
return ioctl_fionbio(filp, argp);
case FIOASYNC:
return ioctl_fioasync(fd, filp, argp);
case FIOQSIZE:
if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode) ||
S_ISLNK(inode->i_mode)) {
loff_t res = inode_get_bytes(inode);
return copy_to_user(argp, &res, sizeof(res)) ?
-EFAULT : 0;
}
return -ENOTTY;
case FIFREEZE:
return ioctl_fsfreeze(filp);
case FITHAW:
return ioctl_fsthaw(filp);
case FS_IOC_FIEMAP:
return ioctl_fiemap(filp, argp);
case FIGETBSZ:
/* anon_bdev filesystems may not have a block size */
if (!inode->i_sb->s_blocksize)
return -EINVAL;
return put_user(inode->i_sb->s_blocksize, (int __user *)argp);
case FICLONE:
return ioctl_file_clone(filp, arg, 0, 0, 0);
case FICLONERANGE:
return ioctl_file_clone_range(filp, argp);
case FIDEDUPERANGE:
return ioctl_file_dedupe_range(filp, argp);
case FIONREAD:
if (!S_ISREG(inode->i_mode))
return vfs_ioctl(filp, cmd, arg);
return put_user(i_size_read(inode) - filp->f_pos,
(int __user *)argp);
case FS_IOC_GETFLAGS:
return ioctl_getflags(filp, argp);
case FS_IOC_SETFLAGS:
return ioctl_setflags(filp, argp);
case FS_IOC_FSGETXATTR:
return ioctl_fsgetxattr(filp, argp);
case FS_IOC_FSSETXATTR:
return ioctl_fssetxattr(filp, argp);
default:
if (S_ISREG(inode->i_mode))
return file_ioctl(filp, cmd, argp);
break;
}
return -ENOIOCTLCMD;
}
SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
{
struct fd f = fdget(fd);
int error;
if (!f.file)
return -EBADF;
error = security_file_ioctl(f.file, cmd, arg);
if (error)
goto out;
error = do_vfs_ioctl(f.file, fd, cmd, arg);
if (error == -ENOIOCTLCMD)
error = vfs_ioctl(f.file, cmd, arg);
out:
fdput(f);
return error;
}
#ifdef CONFIG_COMPAT
/**
* compat_ptr_ioctl - generic implementation of .compat_ioctl file operation
* @file: The file to operate on.
* @cmd: The ioctl command number.
* @arg: The argument to the ioctl.
*
* This is not normally called as a function, but instead set in struct
* file_operations as
*
* .compat_ioctl = compat_ptr_ioctl,
*
* On most architectures, the compat_ptr_ioctl() just passes all arguments
* to the corresponding ->ioctl handler. The exception is arch/s390, where
* compat_ptr() clears the top bit of a 32-bit pointer value, so user space
* pointers to the second 2GB alias the first 2GB, as is the case for
* native 32-bit s390 user space.
*
* The compat_ptr_ioctl() function must therefore be used only with ioctl
* functions that either ignore the argument or pass a pointer to a
* compatible data type.
*
* If any ioctl command handled by fops->unlocked_ioctl passes a plain
* integer instead of a pointer, or any of the passed data types
* is incompatible between 32-bit and 64-bit architectures, a proper
* handler is required instead of compat_ptr_ioctl.
*/
long compat_ptr_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
if (!file->f_op->unlocked_ioctl)
return -ENOIOCTLCMD;
return file->f_op->unlocked_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
}
EXPORT_SYMBOL(compat_ptr_ioctl);
COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd,
compat_ulong_t, arg)
{
struct fd f = fdget(fd);
int error;
if (!f.file)
return -EBADF;
error = security_file_ioctl_compat(f.file, cmd, arg);
if (error)
goto out;
switch (cmd) {
/* FICLONE takes an int argument, so don't use compat_ptr() */
case FICLONE:
error = ioctl_file_clone(f.file, arg, 0, 0, 0);
break;
#if defined(CONFIG_X86_64)
/* these get messy on amd64 due to alignment differences */
case FS_IOC_RESVSP_32:
case FS_IOC_RESVSP64_32:
error = compat_ioctl_preallocate(f.file, 0, compat_ptr(arg));
break;
case FS_IOC_UNRESVSP_32:
case FS_IOC_UNRESVSP64_32:
error = compat_ioctl_preallocate(f.file, FALLOC_FL_PUNCH_HOLE,
compat_ptr(arg));
break;
case FS_IOC_ZERO_RANGE_32:
error = compat_ioctl_preallocate(f.file, FALLOC_FL_ZERO_RANGE,
compat_ptr(arg));
break;
#endif
/*
* These access 32-bit values anyway so no further handling is
* necessary.
*/
case FS_IOC32_GETFLAGS:
case FS_IOC32_SETFLAGS:
cmd = (cmd == FS_IOC32_GETFLAGS) ?
FS_IOC_GETFLAGS : FS_IOC_SETFLAGS;
fallthrough;
/*
* everything else in do_vfs_ioctl() takes either a compatible
* pointer argument or no argument -- call it with a modified
* argument.
*/
default:
error = do_vfs_ioctl(f.file, fd, cmd,
(unsigned long)compat_ptr(arg));
if (error != -ENOIOCTLCMD)
break;
if (f.file->f_op->compat_ioctl)
error = f.file->f_op->compat_ioctl(f.file, cmd, arg);
if (error == -ENOIOCTLCMD)
error = -ENOTTY;
break;
}
out:
fdput(f);
return error;
}
#endif