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-rw-r--r--fs/namei.c73
1 files changed, 48 insertions, 25 deletions
diff --git a/fs/namei.c b/fs/namei.c
index a7b05bf82d31..78512898d3ba 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -416,6 +416,7 @@ int __inode_permission(struct inode *inode, int mask)
return security_inode_permission(inode, mask);
}
+EXPORT_SYMBOL(__inode_permission);
/**
* sb_permission - Check superblock-level permissions
@@ -1306,7 +1307,8 @@ static struct dentry *lookup_dcache(struct qstr *name, struct dentry *dir,
if (error < 0) {
dput(dentry);
return ERR_PTR(error);
- } else if (!d_invalidate(dentry)) {
+ } else {
+ d_invalidate(dentry);
dput(dentry);
dentry = NULL;
}
@@ -1435,10 +1437,9 @@ unlazy:
dput(dentry);
return status;
}
- if (!d_invalidate(dentry)) {
- dput(dentry);
- goto need_lookup;
- }
+ d_invalidate(dentry);
+ dput(dentry);
+ goto need_lookup;
}
path->mnt = mnt;
@@ -1950,7 +1951,7 @@ static int path_lookupat(int dfd, const char *name,
err = path_init(dfd, name, flags | LOOKUP_PARENT, nd, &base);
if (unlikely(err))
- return err;
+ goto out;
current->total_link_count = 0;
err = link_path_walk(name, nd);
@@ -1982,6 +1983,7 @@ static int path_lookupat(int dfd, const char *name,
}
}
+out:
if (base)
fput(base);
@@ -2301,7 +2303,7 @@ path_mountpoint(int dfd, const char *name, struct path *path, unsigned int flags
err = path_init(dfd, name, flags | LOOKUP_PARENT, &nd, &base);
if (unlikely(err))
- return err;
+ goto out;
current->total_link_count = 0;
err = link_path_walk(name, &nd);
@@ -2382,22 +2384,17 @@ kern_path_mountpoint(int dfd, const char *name, struct path *path,
}
EXPORT_SYMBOL(kern_path_mountpoint);
-/*
- * It's inline, so penalty for filesystems that don't use sticky bit is
- * minimal.
- */
-static inline int check_sticky(struct inode *dir, struct inode *inode)
+int __check_sticky(struct inode *dir, struct inode *inode)
{
kuid_t fsuid = current_fsuid();
- if (!(dir->i_mode & S_ISVTX))
- return 0;
if (uid_eq(inode->i_uid, fsuid))
return 0;
if (uid_eq(dir->i_uid, fsuid))
return 0;
return !capable_wrt_inode_uidgid(inode, CAP_FOWNER);
}
+EXPORT_SYMBOL(__check_sticky);
/*
* Check whether we can remove a link victim from directory dir, check
@@ -3063,9 +3060,12 @@ finish_open_created:
error = may_open(&nd->path, acc_mode, open_flag);
if (error)
goto out;
- file->f_path.mnt = nd->path.mnt;
- error = finish_open(file, nd->path.dentry, NULL, opened);
- if (error) {
+
+ BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */
+ error = vfs_open(&nd->path, file, current_cred());
+ if (!error) {
+ *opened |= FILE_OPENED;
+ } else {
if (error == -EOPENSTALE)
goto stale_open;
goto out;
@@ -3074,7 +3074,7 @@ opened:
error = open_check_o_direct(file);
if (error)
goto exit_fput;
- error = ima_file_check(file, op->acc_mode);
+ error = ima_file_check(file, op->acc_mode, *opened);
if (error)
goto exit_fput;
@@ -3154,7 +3154,8 @@ static int do_tmpfile(int dfd, struct filename *pathname,
if (error)
goto out2;
audit_inode(pathname, nd->path.dentry, 0);
- error = may_open(&nd->path, op->acc_mode, op->open_flag);
+ /* Don't check for other permissions, the inode was just created */
+ error = may_open(&nd->path, MAY_OPEN, op->open_flag);
if (error)
goto out2;
file->f_path.mnt = nd->path.mnt;
@@ -3565,7 +3566,7 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry)
mutex_lock(&dentry->d_inode->i_mutex);
error = -EBUSY;
- if (d_mountpoint(dentry))
+ if (is_local_mountpoint(dentry))
goto out;
error = security_inode_rmdir(dir, dentry);
@@ -3579,6 +3580,7 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry)
dentry->d_inode->i_flags |= S_DEAD;
dont_mount(dentry);
+ detach_mounts(dentry);
out:
mutex_unlock(&dentry->d_inode->i_mutex);
@@ -3681,7 +3683,7 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry, struct inode **delegate
return -EPERM;
mutex_lock(&target->i_mutex);
- if (d_mountpoint(dentry))
+ if (is_local_mountpoint(dentry))
error = -EBUSY;
else {
error = security_inode_unlink(dir, dentry);
@@ -3690,8 +3692,10 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry, struct inode **delegate
if (error)
goto out;
error = dir->i_op->unlink(dir, dentry);
- if (!error)
+ if (!error) {
dont_mount(dentry);
+ detach_mounts(dentry);
+ }
}
}
out:
@@ -4126,7 +4130,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
mutex_lock(&target->i_mutex);
error = -EBUSY;
- if (d_mountpoint(old_dentry) || d_mountpoint(new_dentry))
+ if (is_local_mountpoint(old_dentry) || is_local_mountpoint(new_dentry))
goto out;
if (max_links && new_dir != old_dir) {
@@ -4164,6 +4168,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
if (is_dir)
target->i_flags |= S_DEAD;
dont_mount(new_dentry);
+ detach_mounts(new_dentry);
}
if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) {
if (!(flags & RENAME_EXCHANGE))
@@ -4205,12 +4210,16 @@ SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname,
bool should_retry = false;
int error;
- if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
+ if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
return -EINVAL;
- if ((flags & RENAME_NOREPLACE) && (flags & RENAME_EXCHANGE))
+ if ((flags & (RENAME_NOREPLACE | RENAME_WHITEOUT)) &&
+ (flags & RENAME_EXCHANGE))
return -EINVAL;
+ if ((flags & RENAME_WHITEOUT) && !capable(CAP_MKNOD))
+ return -EPERM;
+
retry:
from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags);
if (IS_ERR(from)) {
@@ -4342,6 +4351,20 @@ SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newna
return sys_renameat2(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
}
+int vfs_whiteout(struct inode *dir, struct dentry *dentry)
+{
+ int error = may_create(dir, dentry);
+ if (error)
+ return error;
+
+ if (!dir->i_op->mknod)
+ return -EPERM;
+
+ return dir->i_op->mknod(dir, dentry,
+ S_IFCHR | WHITEOUT_MODE, WHITEOUT_DEV);
+}
+EXPORT_SYMBOL(vfs_whiteout);
+
int readlink_copy(char __user *buffer, int buflen, const char *link)
{
int len = PTR_ERR(link);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.