From 7b0e492e6b80d51db4156996b248522c7b50d467 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 1 Jul 2019 08:25:35 -0700 Subject: [PATCH] vfs: create a generic checking function for FS_IOC_FSSETXATTR Create a generic checking function for the incoming FS_IOC_FSSETXATTR fsxattr values so that we can standardize some of the implementation behaviors. Signed-off-by: Darrick J. Wong Reviewed-by: Jan Kara --- fs/btrfs/ioctl.c | 17 ++++-------- fs/ext4/ioctl.c | 25 +++++++++++------ fs/inode.c | 23 ++++++++++++++++ fs/xfs/xfs_ioctl.c | 69 +++++++++++++++++++++++++++------------------- include/linux/fs.h | 9 ++++++ 5 files changed, 95 insertions(+), 48 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index d3d9b4abb09b..3cd66efdb99d 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -375,9 +375,7 @@ static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg) struct btrfs_inode *binode = BTRFS_I(file_inode(file)); struct fsxattr fa; - memset(&fa, 0, sizeof(fa)); - fa.fsx_xflags = btrfs_inode_flags_to_xflags(binode->flags); - + simple_fill_fsxattr(&fa, btrfs_inode_flags_to_xflags(binode->flags)); if (copy_to_user(arg, &fa, sizeof(fa))) return -EFAULT; @@ -390,7 +388,7 @@ static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg) struct btrfs_inode *binode = BTRFS_I(inode); struct btrfs_root *root = binode->root; struct btrfs_trans_handle *trans; - struct fsxattr fa; + struct fsxattr fa, old_fa; unsigned old_flags; unsigned old_i_flags; int ret = 0; @@ -401,7 +399,6 @@ static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg) if (btrfs_root_readonly(root)) return -EROFS; - memset(&fa, 0, sizeof(fa)); if (copy_from_user(&fa, arg, sizeof(fa))) return -EFAULT; @@ -421,13 +418,11 @@ static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg) old_flags = binode->flags; old_i_flags = inode->i_flags; - /* We need the capabilities to change append-only or immutable inode */ - if (((old_flags & (BTRFS_INODE_APPEND | BTRFS_INODE_IMMUTABLE)) || - (fa.fsx_xflags & (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE))) && - !capable(CAP_LINUX_IMMUTABLE)) { - ret = -EPERM; + simple_fill_fsxattr(&old_fa, + btrfs_inode_flags_to_xflags(binode->flags)); + ret = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa); + if (ret) goto out_unlock; - } if (fa.fsx_xflags & FS_XFLAG_SYNC) binode->flags |= BTRFS_INODE_SYNC; diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index 272b6e44191b..1974cb755d09 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -721,6 +721,17 @@ static int ext4_ioctl_check_project(struct inode *inode, struct fsxattr *fa) return 0; } +static void ext4_fill_fsxattr(struct inode *inode, struct fsxattr *fa) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + + simple_fill_fsxattr(fa, ext4_iflags_to_xflags(ei->i_flags & + EXT4_FL_USER_VISIBLE)); + + if (ext4_has_feature_project(inode->i_sb)) + fa->fsx_projid = from_kprojid(&init_user_ns, ei->i_projid); +} + long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct inode *inode = file_inode(filp); @@ -1089,13 +1100,7 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct fsxattr fa; - memset(&fa, 0, sizeof(struct fsxattr)); - fa.fsx_xflags = ext4_iflags_to_xflags(ei->i_flags & EXT4_FL_USER_VISIBLE); - - if (ext4_has_feature_project(inode->i_sb)) { - fa.fsx_projid = (__u32)from_kprojid(&init_user_ns, - EXT4_I(inode)->i_projid); - } + ext4_fill_fsxattr(inode, &fa); if (copy_to_user((struct fsxattr __user *)arg, &fa, sizeof(fa))) @@ -1104,7 +1109,7 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) } case EXT4_IOC_FSSETXATTR: { - struct fsxattr fa; + struct fsxattr fa, old_fa; int err; if (copy_from_user(&fa, (struct fsxattr __user *)arg, @@ -1127,7 +1132,11 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return err; inode_lock(inode); + ext4_fill_fsxattr(inode, &old_fa); err = ext4_ioctl_check_project(inode, &fa); + if (err) + goto out; + err = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa); if (err) goto out; flags = (ei->i_flags & ~EXT4_FL_XFLAG_VISIBLE) | diff --git a/fs/inode.c b/fs/inode.c index 8072a09fd0b9..ba2bafa22885 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2194,3 +2194,26 @@ int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags, return 0; } EXPORT_SYMBOL(vfs_ioc_setflags_prepare); + +/* + * Generic function to check FS_IOC_FSSETXATTR values and reject any invalid + * configurations. + * + * Note: the caller should be holding i_mutex, or else be sure that they have + * exclusive access to the inode structure. + */ +int vfs_ioc_fssetxattr_check(struct inode *inode, const struct fsxattr *old_fa, + struct fsxattr *fa) +{ + /* + * Can't modify an immutable/append-only file unless we have + * appropriate permission. + */ + if ((old_fa->fsx_xflags ^ fa->fsx_xflags) & + (FS_XFLAG_IMMUTABLE | FS_XFLAG_APPEND) && + !capable(CAP_LINUX_IMMUTABLE)) + return -EPERM; + + return 0; +} +EXPORT_SYMBOL(vfs_ioc_fssetxattr_check); diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index d7dfc13f30f5..458a7043b4d2 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -879,37 +879,44 @@ xfs_di2lxflags( return flags; } -STATIC int -xfs_ioc_fsgetxattr( - xfs_inode_t *ip, - int attr, - void __user *arg) +static void +xfs_fill_fsxattr( + struct xfs_inode *ip, + bool attr, + struct fsxattr *fa) { - struct fsxattr fa; - - memset(&fa, 0, sizeof(struct fsxattr)); - - xfs_ilock(ip, XFS_ILOCK_SHARED); - fa.fsx_xflags = xfs_ip2xflags(ip); - fa.fsx_extsize = ip->i_d.di_extsize << ip->i_mount->m_sb.sb_blocklog; - fa.fsx_cowextsize = ip->i_d.di_cowextsize << + simple_fill_fsxattr(fa, xfs_ip2xflags(ip)); + fa->fsx_extsize = ip->i_d.di_extsize << ip->i_mount->m_sb.sb_blocklog; + fa->fsx_cowextsize = ip->i_d.di_cowextsize << ip->i_mount->m_sb.sb_blocklog; - fa.fsx_projid = xfs_get_projid(ip); + fa->fsx_projid = xfs_get_projid(ip); if (attr) { if (ip->i_afp) { if (ip->i_afp->if_flags & XFS_IFEXTENTS) - fa.fsx_nextents = xfs_iext_count(ip->i_afp); + fa->fsx_nextents = xfs_iext_count(ip->i_afp); else - fa.fsx_nextents = ip->i_d.di_anextents; + fa->fsx_nextents = ip->i_d.di_anextents; } else - fa.fsx_nextents = 0; + fa->fsx_nextents = 0; } else { if (ip->i_df.if_flags & XFS_IFEXTENTS) - fa.fsx_nextents = xfs_iext_count(&ip->i_df); + fa->fsx_nextents = xfs_iext_count(&ip->i_df); else - fa.fsx_nextents = ip->i_d.di_nextents; + fa->fsx_nextents = ip->i_d.di_nextents; } +} + +STATIC int +xfs_ioc_fsgetxattr( + xfs_inode_t *ip, + int attr, + void __user *arg) +{ + struct fsxattr fa; + + xfs_ilock(ip, XFS_ILOCK_SHARED); + xfs_fill_fsxattr(ip, attr, &fa); xfs_iunlock(ip, XFS_ILOCK_SHARED); if (copy_to_user(arg, &fa, sizeof(fa))) @@ -1035,15 +1042,6 @@ xfs_ioctl_setattr_xflags( if ((fa->fsx_xflags & FS_XFLAG_DAX) && xfs_is_reflink_inode(ip)) return -EINVAL; - /* - * Can't modify an immutable/append-only file unless - * we have appropriate permission. - */ - if (((ip->i_d.di_flags & (XFS_DIFLAG_IMMUTABLE | XFS_DIFLAG_APPEND)) || - (fa->fsx_xflags & (FS_XFLAG_IMMUTABLE | FS_XFLAG_APPEND))) && - !capable(CAP_LINUX_IMMUTABLE)) - return -EPERM; - /* diflags2 only valid for v3 inodes. */ di_flags2 = xfs_flags2diflags2(ip, fa->fsx_xflags); if (di_flags2 && ip->i_d.di_version < 3) @@ -1323,6 +1321,7 @@ xfs_ioctl_setattr( xfs_inode_t *ip, struct fsxattr *fa) { + struct fsxattr old_fa; struct xfs_mount *mp = ip->i_mount; struct xfs_trans *tp; struct xfs_dquot *udqp = NULL; @@ -1370,7 +1369,6 @@ xfs_ioctl_setattr( goto error_free_dquots; } - if (XFS_IS_QUOTA_RUNNING(mp) && XFS_IS_PQUOTA_ON(mp) && xfs_get_projid(ip) != fa->fsx_projid) { code = xfs_qm_vop_chown_reserve(tp, ip, udqp, NULL, pdqp, @@ -1379,6 +1377,11 @@ xfs_ioctl_setattr( goto error_trans_cancel; } + xfs_fill_fsxattr(ip, false, &old_fa); + code = vfs_ioc_fssetxattr_check(VFS_I(ip), &old_fa, fa); + if (code) + goto error_trans_cancel; + code = xfs_ioctl_setattr_check_extsize(ip, fa); if (code) goto error_trans_cancel; @@ -1489,6 +1492,7 @@ xfs_ioc_setxflags( { struct xfs_trans *tp; struct fsxattr fa; + struct fsxattr old_fa; unsigned int flags; int join_flags = 0; int error; @@ -1524,6 +1528,13 @@ xfs_ioc_setxflags( goto out_drop_write; } + xfs_fill_fsxattr(ip, false, &old_fa); + error = vfs_ioc_fssetxattr_check(VFS_I(ip), &old_fa, &fa); + if (error) { + xfs_trans_cancel(tp); + goto out_drop_write; + } + error = xfs_ioctl_setattr_xflags(tp, ip, &fa); if (error) { xfs_trans_cancel(tp); diff --git a/include/linux/fs.h b/include/linux/fs.h index 41d5175ffdd7..36f9691d7046 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3549,4 +3549,13 @@ static inline struct sock *io_uring_get_socket(struct file *file) int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags, unsigned int flags); +int vfs_ioc_fssetxattr_check(struct inode *inode, const struct fsxattr *old_fa, + struct fsxattr *fa); + +static inline void simple_fill_fsxattr(struct fsxattr *fa, __u32 xflags) +{ + memset(fa, 0, sizeof(*fa)); + fa->fsx_xflags = xflags; +} + #endif /* _LINUX_FS_H */ -- GitLab