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Diffstat (limited to 'fs')
-rw-r--r--fs/attr.c36
-rw-r--r--fs/ioctl.c4
-rw-r--r--fs/namei.c16
-rw-r--r--fs/namespace.c4
4 files changed, 44 insertions, 16 deletions
diff --git a/fs/attr.c b/fs/attr.c
index 12ffdb6fb63c..d0b4d34878fb 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -18,6 +18,32 @@
#include <linux/evm.h>
#include <linux/ima.h>
+static bool chown_ok(const struct inode *inode, kuid_t uid)
+{
+ if (uid_eq(current_fsuid(), inode->i_uid) &&
+ uid_eq(uid, inode->i_uid))
+ return true;
+ if (capable_wrt_inode_uidgid(inode, CAP_CHOWN))
+ return true;
+ if (uid_eq(inode->i_uid, INVALID_UID) &&
+ ns_capable(inode->i_sb->s_user_ns, CAP_CHOWN))
+ return true;
+ return false;
+}
+
+static bool chgrp_ok(const struct inode *inode, kgid_t gid)
+{
+ if (uid_eq(current_fsuid(), inode->i_uid) &&
+ (in_group_p(gid) || gid_eq(gid, inode->i_gid)))
+ return true;
+ if (capable_wrt_inode_uidgid(inode, CAP_CHOWN))
+ return true;
+ if (gid_eq(inode->i_gid, INVALID_GID) &&
+ ns_capable(inode->i_sb->s_user_ns, CAP_CHOWN))
+ return true;
+ return false;
+}
+
/**
* setattr_prepare - check if attribute changes to a dentry are allowed
* @dentry: dentry to check
@@ -52,17 +78,11 @@ int setattr_prepare(struct dentry *dentry, struct iattr *attr)
goto kill_priv;
/* Make sure a caller can chown. */
- if ((ia_valid & ATTR_UID) &&
- (!uid_eq(current_fsuid(), inode->i_uid) ||
- !uid_eq(attr->ia_uid, inode->i_uid)) &&
- !capable_wrt_inode_uidgid(inode, CAP_CHOWN))
+ if ((ia_valid & ATTR_UID) && !chown_ok(inode, attr->ia_uid))
return -EPERM;
/* Make sure caller can chgrp. */
- if ((ia_valid & ATTR_GID) &&
- (!uid_eq(current_fsuid(), inode->i_uid) ||
- (!in_group_p(attr->ia_gid) && !gid_eq(attr->ia_gid, inode->i_gid))) &&
- !capable_wrt_inode_uidgid(inode, CAP_CHOWN))
+ if ((ia_valid & ATTR_GID) && !chgrp_ok(inode, attr->ia_gid))
return -EPERM;
/* Make sure a caller can chmod. */
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 4823431d1c9d..b445b13fc59b 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -549,7 +549,7 @@ static int ioctl_fsfreeze(struct file *filp)
{
struct super_block *sb = file_inode(filp)->i_sb;
- if (!capable(CAP_SYS_ADMIN))
+ if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
return -EPERM;
/* If filesystem doesn't support freeze feature, return. */
@@ -566,7 +566,7 @@ static int ioctl_fsthaw(struct file *filp)
{
struct super_block *sb = file_inode(filp)->i_sb;
- if (!capable(CAP_SYS_ADMIN))
+ if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
return -EPERM;
/* Thaw */
diff --git a/fs/namei.c b/fs/namei.c
index a59968de1636..6df1f61855d6 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -984,13 +984,15 @@ static bool safe_hardlink_source(struct inode *inode)
*/
static int may_linkat(struct path *link)
{
- struct inode *inode;
+ struct inode *inode = link->dentry->d_inode;
+
+ /* Inode writeback is not safe when the uid or gid are invalid. */
+ if (!uid_valid(inode->i_uid) || !gid_valid(inode->i_gid))
+ return -EOVERFLOW;
if (!sysctl_protected_hardlinks)
return 0;
- inode = link->dentry->d_inode;
-
/* Source inode owner (or CAP_FOWNER) can hardlink all they like,
* otherwise, it must be a safe source.
*/
@@ -2747,6 +2749,11 @@ static int may_delete(struct inode *dir, struct dentry *victim, bool isdir)
BUG_ON(!inode);
BUG_ON(victim->d_parent->d_inode != dir);
+
+ /* Inode writeback is not safe when the uid or gid are invalid. */
+ if (!uid_valid(inode->i_uid) || !gid_valid(inode->i_gid))
+ return -EOVERFLOW;
+
audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
@@ -3675,7 +3682,8 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
if (error)
return error;
- if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD))
+ if ((S_ISCHR(mode) || S_ISBLK(mode)) &&
+ !ns_capable(dentry->d_sb->s_user_ns, CAP_MKNOD))
return -EPERM;
if (!dir->i_op->mknod)
diff --git a/fs/namespace.c b/fs/namespace.c
index 5f75969adff1..8ddd14806799 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1590,7 +1590,7 @@ static int do_umount(struct mount *mnt, int flags)
* Special case for "unmounting" root ...
* we just try to remount it readonly.
*/
- if (!capable(CAP_SYS_ADMIN))
+ if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
return -EPERM;
down_write(&sb->s_umount);
if (!sb_rdonly(sb))
@@ -2333,7 +2333,7 @@ static int do_remount(struct path *path, int ms_flags, int sb_flags,
down_write(&sb->s_umount);
if (ms_flags & MS_BIND)
err = change_mount_flags(path->mnt, ms_flags);
- else if (!capable(CAP_SYS_ADMIN))
+ else if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
err = -EPERM;
else
err = do_remount_sb(sb, sb_flags, data, 0);