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| author | Amir Goldstein <amir73il@gmail.com> | 2020-09-29 15:28:48 +0800 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2020-10-06 15:38:15 +0200 |
| commit | be4df0cea08a8b59eb38d73de988b7ba8022df41 (patch) | |
| tree | 46ca211e654e6bb65b9a8bf7f99c9126fd8ba4f9 /fs/overlayfs/file.c | |
| parent | 61536bed2149b082748f8a38c593d915ff3e5957 (diff) | |
| download | linux-be4df0cea08a8b59eb38d73de988b7ba8022df41.tar.bz2 | |
ovl: use generic vfs_ioc_setflags_prepare() helper
Canonalize to ioctl FS_* flags instead of inode S_* flags.
Note that we do not call the helper vfs_ioc_fssetxattr_check()
for FS_IOC_FSSETXATTR ioctl. The reason is that underlying filesystem
will perform all the checks. We only need to perform the capability
check before overriding credentials.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/file.c')
| -rw-r--r-- | fs/overlayfs/file.c | 62 |
1 files changed, 30 insertions, 32 deletions
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index 443986ca564b..efccb7c1f9bc 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -559,12 +559,28 @@ static long ovl_real_ioctl(struct file *file, unsigned int cmd, return ret; } +static unsigned int ovl_iflags_to_fsflags(unsigned int iflags) +{ + unsigned int flags = 0; + + if (iflags & S_SYNC) + flags |= FS_SYNC_FL; + if (iflags & S_APPEND) + flags |= FS_APPEND_FL; + if (iflags & S_IMMUTABLE) + flags |= FS_IMMUTABLE_FL; + if (iflags & S_NOATIME) + flags |= FS_NOATIME_FL; + + return flags; +} + static long ovl_ioctl_set_flags(struct file *file, unsigned int cmd, - unsigned long arg, unsigned int iflags) + unsigned long arg, unsigned int flags) { long ret; struct inode *inode = file_inode(file); - unsigned int old_iflags; + unsigned int oldflags; if (!inode_owner_or_capable(inode)) return -EACCES; @@ -576,10 +592,9 @@ static long ovl_ioctl_set_flags(struct file *file, unsigned int cmd, inode_lock(inode); /* Check the capability before cred override */ - ret = -EPERM; - old_iflags = READ_ONCE(inode->i_flags); - if (((iflags ^ old_iflags) & (S_APPEND | S_IMMUTABLE)) && - !capable(CAP_LINUX_IMMUTABLE)) + oldflags = ovl_iflags_to_fsflags(READ_ONCE(inode->i_flags)); + ret = vfs_ioc_setflags_prepare(inode, oldflags, flags); + if (ret) goto unlock; ret = ovl_maybe_copy_up(file_dentry(file), O_WRONLY); @@ -598,22 +613,6 @@ unlock: } -static unsigned int ovl_fsflags_to_iflags(unsigned int flags) -{ - unsigned int iflags = 0; - - if (flags & FS_SYNC_FL) - iflags |= S_SYNC; - if (flags & FS_APPEND_FL) - iflags |= S_APPEND; - if (flags & FS_IMMUTABLE_FL) - iflags |= S_IMMUTABLE; - if (flags & FS_NOATIME_FL) - iflags |= S_NOATIME; - - return iflags; -} - static long ovl_ioctl_set_fsflags(struct file *file, unsigned int cmd, unsigned long arg) { @@ -622,24 +621,23 @@ static long ovl_ioctl_set_fsflags(struct file *file, unsigned int cmd, if (get_user(flags, (int __user *) arg)) return -EFAULT; - return ovl_ioctl_set_flags(file, cmd, arg, - ovl_fsflags_to_iflags(flags)); + return ovl_ioctl_set_flags(file, cmd, arg, flags); } -static unsigned int ovl_fsxflags_to_iflags(unsigned int xflags) +static unsigned int ovl_fsxflags_to_fsflags(unsigned int xflags) { - unsigned int iflags = 0; + unsigned int flags = 0; if (xflags & FS_XFLAG_SYNC) - iflags |= S_SYNC; + flags |= FS_SYNC_FL; if (xflags & FS_XFLAG_APPEND) - iflags |= S_APPEND; + flags |= FS_APPEND_FL; if (xflags & FS_XFLAG_IMMUTABLE) - iflags |= S_IMMUTABLE; + flags |= FS_IMMUTABLE_FL; if (xflags & FS_XFLAG_NOATIME) - iflags |= S_NOATIME; + flags |= FS_NOATIME_FL; - return iflags; + return flags; } static long ovl_ioctl_set_fsxflags(struct file *file, unsigned int cmd, @@ -652,7 +650,7 @@ static long ovl_ioctl_set_fsxflags(struct file *file, unsigned int cmd, return -EFAULT; return ovl_ioctl_set_flags(file, cmd, arg, - ovl_fsxflags_to_iflags(fa.fsx_xflags)); + ovl_fsxflags_to_fsflags(fa.fsx_xflags)); } long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |