Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull misc vfs updates from Al Viro:
 "All kinds of stuff.  That probably should've been 5 or 6 separate
  branches, but by the time I'd realized how large and mixed that bag
  had become it had been too close to -final to play with rebasing.

  Some fs/namei.c cleanups there, memdup_user_nul() introduction and
  switching open-coded instances, burying long-dead code, whack-a-mole
  of various kinds, several new helpers for ->llseek(), assorted
  cleanups and fixes from various people, etc.

  One piece probably deserves special mention - Neil's
  lookup_one_len_unlocked().  Similar to lookup_one_len(), but gets
  called without ->i_mutex and tries to avoid ever taking it.  That, of
  course, means that it's not useful for any directory modifications,
  but things like getting inode attributes in nfds readdirplus are fine
  with that.  I really should've asked for moratorium on lookup-related
  changes this cycle, but since I hadn't done that early enough...  I
  *am* asking for that for the coming cycle, though - I'm going to try
  and get conversion of i_mutex to rwsem with ->lookup() done under lock
  taken shared.

  There will be a patch closer to the end of the window, along the lines
  of the one Linus had posted last May - mechanical conversion of
  ->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/
  inode_is_locked()/inode_lock_nested().  To quote Linus back then:

    -----
    |    This is an automated patch using
    |
    |        sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/'
    |        sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/'
    |        sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[     ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/'
    |        sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/'
    |        sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/'
    |
    |    with a very few manual fixups
    -----

  I'm going to send that once the ->i_mutex-affecting stuff in -next
  gets mostly merged (or when Linus says he's about to stop taking
  merges)"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  nfsd: don't hold i_mutex over userspace upcalls
  fs:affs:Replace time_t with time64_t
  fs/9p: use fscache mutex rather than spinlock
  proc: add a reschedule point in proc_readfd_common()
  logfs: constify logfs_block_ops structures
  fcntl: allow to set O_DIRECT flag on pipe
  fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE
  fs: xattr: Use kvfree()
  [s390] page_to_phys() always returns a multiple of PAGE_SIZE
  nbd: use ->compat_ioctl()
  fs: use block_device name vsprintf helper
  lib/vsprintf: add %*pg format specifier
  fs: use gendisk->disk_name where possible
  poll: plug an unused argument to do_poll
  amdkfd: don't open-code memdup_user()
  cdrom: don't open-code memdup_user()
  rsxx: don't open-code memdup_user()
  mtip32xx: don't open-code memdup_user()
  [um] mconsole: don't open-code memdup_user_nul()
  [um] hostaudio: don't open-code memdup_user()
  ...

1 files changed, 32 insertions, 82 deletions

diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 94bd9e41c9ec..e249a66db533 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -497,14 +497,9 @@ static ssize_t smk_write_rules_list(struct file *file, const char __user *buf,
 		}
 	}
 
-	data = kmalloc(count + 1, GFP_KERNEL);
-	if (data == NULL)
-		return -ENOMEM;
-
-	if (copy_from_user(data, buf, count) != 0) {
-		rc = -EFAULT;
-		goto out;
-	}
+	data = memdup_user_nul(buf, count);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
 
 	/*
 	 * In case of parsing only part of user buf,
@@ -884,16 +879,10 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
 	    (count < SMK_CIPSOMIN || count > SMK_CIPSOMAX))
 		return -EINVAL;
 
-	data = kzalloc(count + 1, GFP_KERNEL);
-	if (data == NULL)
-		return -ENOMEM;
-
-	if (copy_from_user(data, buf, count) != 0) {
-		rc = -EFAULT;
-		goto unlockedout;
-	}
+	data = memdup_user_nul(buf, count);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
 
-	data[count] = '\0';
 	rule = data;
 	/*
 	 * Only allow one writer at a time. Writes should be
@@ -946,7 +935,6 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
 
 out:
 	mutex_unlock(&smack_cipso_lock);
-unlockedout:
 	kfree(data);
 	return rc;
 }
@@ -1187,14 +1175,9 @@ static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
 	if (count < SMK_NETLBLADDRMIN)
 		return -EINVAL;
 
-	data = kzalloc(count + 1, GFP_KERNEL);
-	if (data == NULL)
-		return -ENOMEM;
-
-	if (copy_from_user(data, buf, count) != 0) {
-		rc = -EFAULT;
-		goto free_data_out;
-	}
+	data = memdup_user_nul(buf, count);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
 
 	smack = kzalloc(count + 1, GFP_KERNEL);
 	if (smack == NULL) {
@@ -1202,8 +1185,6 @@ static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
 		goto free_data_out;
 	}
 
-	data[count] = '\0';
-
 	rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd/%u %s",
 		&host[0], &host[1], &host[2], &host[3], &masks, smack);
 	if (rc != 6) {
@@ -1454,14 +1435,9 @@ static ssize_t smk_write_net6addr(struct file *file, const char __user *buf,
 	if (count < SMK_NETLBLADDRMIN)
 		return -EINVAL;
 
-	data = kzalloc(count + 1, GFP_KERNEL);
-	if (data == NULL)
-		return -ENOMEM;
-
-	if (copy_from_user(data, buf, count) != 0) {
-		rc = -EFAULT;
-		goto free_data_out;
-	}
+	data = memdup_user_nul(buf, count);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
 
 	smack = kzalloc(count + 1, GFP_KERNEL);
 	if (smack == NULL) {
@@ -1469,8 +1445,6 @@ static ssize_t smk_write_net6addr(struct file *file, const char __user *buf,
 		goto free_data_out;
 	}
 
-	data[count] = '\0';
-
 	i = sscanf(data, "%x:%x:%x:%x:%x:%x:%x:%x/%u %s",
 			&scanned[0], &scanned[1], &scanned[2], &scanned[3],
 			&scanned[4], &scanned[5], &scanned[6], &scanned[7],
@@ -1865,14 +1839,9 @@ static ssize_t smk_write_ambient(struct file *file, const char __user *buf,
 	if (!smack_privileged(CAP_MAC_ADMIN))
 		return -EPERM;
 
-	data = kzalloc(count + 1, GFP_KERNEL);
-	if (data == NULL)
-		return -ENOMEM;
-
-	if (copy_from_user(data, buf, count) != 0) {
-		rc = -EFAULT;
-		goto out;
-	}
+	data = memdup_user_nul(buf, count);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
 
 	skp = smk_import_entry(data, count);
 	if (IS_ERR(skp)) {
@@ -2041,14 +2010,9 @@ static ssize_t smk_write_onlycap(struct file *file, const char __user *buf,
 	if (!smack_privileged(CAP_MAC_ADMIN))
 		return -EPERM;
 
-	data = kzalloc(count + 1, GFP_KERNEL);
-	if (data == NULL)
-		return -ENOMEM;
-
-	if (copy_from_user(data, buf, count) != 0) {
-		kfree(data);
-		return -EFAULT;
-	}
+	data = memdup_user_nul(buf, count);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
 
 	rc = smk_parse_label_list(data, &list_tmp);
 	kfree(data);
@@ -2133,14 +2097,9 @@ static ssize_t smk_write_unconfined(struct file *file, const char __user *buf,
 	if (!smack_privileged(CAP_MAC_ADMIN))
 		return -EPERM;
 
-	data = kzalloc(count + 1, GFP_KERNEL);
-	if (data == NULL)
-		return -ENOMEM;
-
-	if (copy_from_user(data, buf, count) != 0) {
-		rc = -EFAULT;
-		goto freeout;
-	}
+	data = memdup_user_nul(buf, count);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
 
 	/*
 	 * Clear the smack_unconfined on invalid label errors. This means
@@ -2696,19 +2655,15 @@ static ssize_t smk_write_syslog(struct file *file, const char __user *buf,
 	if (!smack_privileged(CAP_MAC_ADMIN))
 		return -EPERM;
 
-	data = kzalloc(count + 1, GFP_KERNEL);
-	if (data == NULL)
-		return -ENOMEM;
+	data = memdup_user_nul(buf, count);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
 
-	if (copy_from_user(data, buf, count) != 0)
-		rc = -EFAULT;
-	else {
-		skp = smk_import_entry(data, count);
-		if (IS_ERR(skp))
-			rc = PTR_ERR(skp);
-		else
-			smack_syslog_label = skp;
-	}
+	skp = smk_import_entry(data, count);
+	if (IS_ERR(skp))
+		rc = PTR_ERR(skp);
+	else
+		smack_syslog_label = skp;
 
 	kfree(data);
 	return rc;
@@ -2798,14 +2753,9 @@ static ssize_t smk_write_relabel_self(struct file *file, const char __user *buf,
 	if (*ppos != 0)
 		return -EINVAL;
 
-	data = kzalloc(count + 1, GFP_KERNEL);
-	if (data == NULL)
-		return -ENOMEM;
-
-	if (copy_from_user(data, buf, count) != 0) {
-		kfree(data);
-		return -EFAULT;
-	}
+	data = memdup_user_nul(buf, count);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
 
 	rc = smk_parse_label_list(data, &list_tmp);
 	kfree(data);