5.14.1-rc1 review

This is the start of the stable review cycle for the 5.14.1 release. There are 11 patches in this series, all will be posted as a response to this one. If anyone has any issues with these being applied, please let me know.

Responses should be made by Fri, 03 Sep 2021 12:22:41 +0000. Anything received after that time might be too late.

The whole patch series can be found in one patch at:

	https://www.kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.14.1-rc1.gz

or in the git tree and branch at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-5.14.y
and the diffstat can be found below.

thanks,

greg k-h

-------------
Pseudo-Shortlog of commits:

Greg Kroah-Hartman <[email protected]>

    Linux 5.14.1-rc1

Richard Guy Briggs <[email protected]>
audit: move put_tree() to avoid trim_trees refcount underflow and UAF

Peter Collingbourne <[email protected]>
net: don't unconditionally copy_from_user a struct ifreq for socket ioctls

Eric Biggers <[email protected]>
ubifs: report correct st_size for encrypted symlinks

Eric Biggers <[email protected]>
f2fs: report correct st_size for encrypted symlinks

Eric Biggers <[email protected]>
ext4: report correct st_size for encrypted symlinks

Eric Biggers <[email protected]>
fscrypt: add fscrypt_symlink_getattr() for computing st_size

Denis Efremov <[email protected]>
Revert "floppy: reintroduce O_NDELAY fix"

Qu Wenruo <[email protected]>
btrfs: fix NULL pointer dereference when deleting device by invalid id

DENG Qingfang <[email protected]>
net: dsa: mt7530: fix VLAN traffic leaks again

Pauli Virtanen <[email protected]>
Bluetooth: btusb: check conditions before enabling USB ALT 3 for WBS

Linus Torvalds <[email protected]>
vt_kdsetmode: extend console locking

-------------

Diffstat:

 Makefile                  |  4 ++--
 drivers/block/floppy.c    | 30 +++++++++++++++---------------
 drivers/bluetooth/btusb.c | 22 ++++++++++++++--------
 drivers/net/dsa/mt7530.c  |  5 +----
 drivers/tty/vt/vt_ioctl.c | 10 ++++++----
 fs/btrfs/volumes.c        |  2 +-
 fs/crypto/hooks.c         | 44 ++++++++++++++++++++++++++++++++++++++++++++
 fs/ext4/symlink.c         | 12 +++++++++++-
 fs/f2fs/namei.c           | 12 +++++++++++-
 fs/ubifs/file.c           | 13 ++++++++++++-
 include/linux/fscrypt.h   |  7 +++++++
 include/linux/netdevice.h |  4 ++++
 kernel/audit_tree.c       |  2 +-
 net/socket.c              |  6 +++++-
 14 files changed, 134 insertions(+), 39 deletions(-)

From: Linus Torvalds <[email protected]>

commit 2287a51ba822384834dafc1c798453375d1107c7 upstream.

As per the long-suffering comment.

---
 drivers/tty/vt/vt_ioctl.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

@@ -246,6 +246,8 @@ int vt_waitactive(int n)
  *
  * XXX It should at least call into the driver, fbdev's definitely need to
  * restore their engine state. --BenH
+ *
+ * Called with the console lock held.
  */
 static int vt_kdsetmode(struct vc_data *vc, unsigned long mode)
 {

@@ -262,7 +264,6 @@ static int vt_kdsetmode(struct vc_data *
 		return -EINVAL;
 	}
 
-	/* FIXME: this needs the console lock extending */
 	if (vc->vc_mode == mode)
 		return 0;
 

@@ -271,12 +272,10 @@ static int vt_kdsetmode(struct vc_data *
 		return 0;
 
 	/* explicitly blank/unblank the screen if switching modes */
-	console_lock();
 	if (mode == KD_TEXT)
 		do_unblank_screen(1);
 	else
 		do_blank_screen(1);
-	console_unlock();
 
 	return 0;
 }

@@ -378,7 +377,10 @@ static int vt_k_ioctl(struct tty_struct
 		if (!perm)
 			return -EPERM;
 
-		return vt_kdsetmode(vc, arg);
+		console_lock();
+		ret = vt_kdsetmode(vc, arg);
+		console_unlock();
+		return ret;
 
 	case KDGETMODE:
 		return put_user(vc->vc_mode, (int __user *)arg);

From: Pauli Virtanen <[email protected]>

commit 55981d3541812234e687062926ff199c83f79a39 upstream.

Some USB BT adapters don't satisfy the MTU requirement mentioned in commit e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS") and have ALT 3 setting that produces no/garbled audio. Some adapters with larger MTU were also reported to have problems with ALT 3.

Add a flag and check it and MTU before selecting ALT 3, falling back to ALT 1. Enable the flag for Realtek, restoring the previous behavior for non-Realtek devices.

Tested with USB adapters (mtu<72, no/garbled sound with ALT3, ALT1 works) BCM20702A1 0b05:17cb, CSR8510A10 0a12:0001, and (mtu>=72, ALT3 works) RTL8761BU 0bda:8771, Intel AX200 8087:0029 (after disabling ALT6). Also got reports for (mtu>=72, ALT 3 reported to produce bad audio) Intel 8087:0a2b.

---
 drivers/bluetooth/btusb.c |   22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

@@ -525,6 +525,7 @@ static const struct dmi_system_id btusb_
 #define BTUSB_HW_RESET_ACTIVE	12
 #define BTUSB_TX_WAIT_VND_EVT	13
 #define BTUSB_WAKEUP_DISABLE	14
+#define BTUSB_USE_ALT3_FOR_WBS	15
 
 struct btusb_data {
 	struct hci_dev       *hdev;

@@ -1757,16 +1758,20 @@ static void btusb_work(struct work_struc
 			/* Bluetooth USB spec recommends alt 6 (63 bytes), but
 			 * many adapters do not support it.  Alt 1 appears to
 			 * work for all adapters that do not have alt 6, and
-			 * which work with WBS at all.
+			 * which work with WBS at all.  Some devices prefer
+			 * alt 3 (HCI payload >= 60 Bytes let air packet
+			 * data satisfy 60 bytes), requiring
+			 * MTU >= 3 (packets) * 25 (size) - 3 (headers) = 72
+			 * see also Core spec 5, vol 4, B 2.1.1 & Table 2.1.
 			 */
-			new_alts = btusb_find_altsetting(data, 6) ? 6 : 1;
-			/* Because mSBC frames do not need to be aligned to the
-			 * SCO packet boundary. If support the Alt 3, use the
-			 * Alt 3 for HCI payload >= 60 Bytes let air packet
-			 * data satisfy 60 bytes.
-			 */
-			if (new_alts == 1 && btusb_find_altsetting(data, 3))
+			if (btusb_find_altsetting(data, 6))
+				new_alts = 6;
+			else if (btusb_find_altsetting(data, 3) &&
+				 hdev->sco_mtu >= 72 &&
+				 test_bit(BTUSB_USE_ALT3_FOR_WBS, &data->flags))
 				new_alts = 3;
+			else
+				new_alts = 1;
 		}
 
 		if (btusb_switch_alt_setting(hdev, new_alts) < 0)

@@ -4742,6 +4747,7 @@ static int btusb_probe(struct usb_interf
 		 * (DEVICE_REMOTE_WAKEUP)
 		 */
 		set_bit(BTUSB_WAKEUP_DISABLE, &data->flags);
+		set_bit(BTUSB_USE_ALT3_FOR_WBS, &data->flags);
 	}
 
 	if (!reset)

From: DENG Qingfang <[email protected]>

commit 7428022b50d0fbb4846dd0f00639ea09d36dff02 upstream.

When a port leaves a VLAN-aware bridge, the current code does not clear other ports' matrix field bit. If the bridge is later set to VLAN-unaware mode, traffic in the bridge may leak to that port.

Remove the VLAN filtering check in mt7530_port_bridge_leave.

---
 drivers/net/dsa/mt7530.c |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

@@ -1308,11 +1308,8 @@ mt7530_port_bridge_leave(struct dsa_swit
 		/* Remove this port from the port matrix of the other ports
 		 * in the same bridge. If the port is disabled, port matrix
 		 * is kept and not being setup until the port becomes enabled.
-		 * And the other port's port matrix cannot be broken when the
-		 * other port is still a VLAN-aware port.
 		 */
-		if (dsa_is_user_port(ds, i) && i != port &&
-		   !dsa_port_is_vlan_filtering(dsa_to_port(ds, i))) {
+		if (dsa_is_user_port(ds, i) && i != port) {
 			if (dsa_to_port(ds, i)->bridge_dev != bridge)
 				continue;
 			if (priv->ports[i].enable)

From: Qu Wenruo <[email protected]>

commit e4571b8c5e9ffa1e85c0c671995bd4dcc5c75091 upstream.

[BUG]
It's easy to trigger NULL pointer dereference, just by removing a non-existing device id:

 # mkfs.btrfs -f -m single -d single /dev/test/scratch1 \
				     /dev/test/scratch2
 # mount /dev/test/scratch1 /mnt/btrfs
 # btrfs device remove 3 /mnt/btrfs

Then we have the following kernel NULL pointer dereference:

 BUG: kernel NULL pointer dereference, address: 0000000000000000
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] PREEMPT SMP NOPTI
 CPU: 9 PID: 649 Comm: btrfs Not tainted 5.14.0-rc3-custom+ #35
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
 RIP: 0010:btrfs_rm_device+0x4de/0x6b0 [btrfs]
  btrfs_ioctl+0x18bb/0x3190 [btrfs]
  ? lock_is_held_type+0xa5/0x120
  ? find_held_lock.constprop.0+0x2b/0x80
  ? do_user_addr_fault+0x201/0x6a0
  ? lock_release+0xd2/0x2d0
  ? __x64_sys_ioctl+0x83/0xb0
  __x64_sys_ioctl+0x83/0xb0
  do_syscall_64+0x3b/0x90
  entry_SYSCALL_64_after_hwframe+0x44/0xae

[CAUSE]
Commit a27a94c2b0c7 ("btrfs: Make btrfs_find_device_by_devspec return btrfs_device directly") moves the "missing" device path check into btrfs_rm_device().

But btrfs_rm_device() itself can have case where it only receives @devid, with NULL as @device_path.

In that case, calling strcmp() on NULL will trigger the NULL pointer dereference.

Before that commit, we handle the "missing" case inside btrfs_find_device_by_devspec(), which will not check @device_path at all if @devid is provided, thus no way to trigger the bug.

[FIX]
Before calling strcmp(), also make sure @device_path is not NULL.

---
 fs/btrfs/volumes.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -2137,7 +2137,7 @@ int btrfs_rm_device(struct btrfs_fs_info
 
 	if (IS_ERR(device)) {
 		if (PTR_ERR(device) == -ENOENT &&
-		    strcmp(device_path, "missing") == 0)
+		    device_path && strcmp(device_path, "missing") == 0)
 			ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
 		else
 			ret = PTR_ERR(device);

From: Denis Efremov <[email protected]>

commit c7e9d0020361f4308a70cdfd6d5335e273eb8717 upstream.

The patch breaks userspace implementations (e.g. fdutils) and introduces regressions in behaviour. Previously, it was possible to O_NDELAY open a floppy device with no media inserted or with write protected media without an error. Some userspace tools use this particular behavior for probing.

It's not the first time when we revert this patch. Previous revert is in commit f2791e7eadf4 (Revert "floppy: refactor open() flags handling").

This reverts commit 8a0c014cd20516ade9654fc13b51345ec58e7be8.

---
 drivers/block/floppy.c |   30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

@@ -4029,23 +4029,23 @@ static int floppy_open(struct block_devi
 	if (fdc_state[FDC(drive)].rawcmd == 1)
 		fdc_state[FDC(drive)].rawcmd = 2;
 
-	if (mode & (FMODE_READ|FMODE_WRITE)) {
-		drive_state[drive].last_checked = 0;
-		clear_bit(FD_OPEN_SHOULD_FAIL_BIT, &drive_state[drive].flags);
-		if (bdev_check_media_change(bdev))
-			floppy_revalidate(bdev->bd_disk);
-		if (test_bit(FD_DISK_CHANGED_BIT, &drive_state[drive].flags))
-			goto out;
-		if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &drive_state[drive].flags))
+	if (!(mode & FMODE_NDELAY)) {
+		if (mode & (FMODE_READ|FMODE_WRITE)) {
+			drive_state[drive].last_checked = 0;
+			clear_bit(FD_OPEN_SHOULD_FAIL_BIT,
+				  &drive_state[drive].flags);
+			if (bdev_check_media_change(bdev))
+				floppy_revalidate(bdev->bd_disk);
+			if (test_bit(FD_DISK_CHANGED_BIT, &drive_state[drive].flags))
+				goto out;
+			if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &drive_state[drive].flags))
+				goto out;
+		}
+		res = -EROFS;
+		if ((mode & FMODE_WRITE) &&
+		    !test_bit(FD_DISK_WRITABLE_BIT, &drive_state[drive].flags))
 			goto out;
 	}
-
-	res = -EROFS;
-
-	if ((mode & FMODE_WRITE) &&
-			!test_bit(FD_DISK_WRITABLE_BIT, &drive_state[drive].flags))
-		goto out;
-
 	mutex_unlock(&open_lock);
 	mutex_unlock(&floppy_mutex);
 	return 0;

From: Eric Biggers <[email protected]>

commit d18760560593e5af921f51a8c9b64b6109d634c2 upstream.

Add a helper function fscrypt_symlink_getattr() which will be called from the various filesystems' ->getattr() methods to read and decrypt the target of encrypted symlinks in order to report the correct st_size.

Detailed explanation:

As required by POSIX and as documented in various man pages, st_size for a symlink is supposed to be the length of the symlink target. Unfortunately, st_size has always been wrong for encrypted symlinks because st_size is populated from i_size from disk, which intentionally contains the length of the encrypted symlink target. That's slightly greater than the length of the decrypted symlink target (which is the symlink target that userspace usually sees), and usually won't match the length of the no-key encoded symlink target either.

This hadn't been fixed yet because reporting the correct st_size would require reading the symlink target from disk and decrypting or encoding it, which historically has been considered too heavyweight to do in ->getattr(). Also historically, the wrong st_size had only broken a test (LTP lstat03) and there were no known complaints from real users. (This is probably because the st_size of symlinks isn't used too often, and when it is, typically it's for a hint for what buffer size to pass to readlink() -- which a slightly-too-large size still works for.)

However, a couple things have changed now. First, there have recently been complaints about the current behavior from real users:

- Breakage in rpmbuild:
https://github.com/rpm-software-management/rpm/issues/1682
https://github.com/google/fscrypt/issues/305

- Breakage in toybox cpio:
https://www.mail-archive.com/[email protected]/msg07193.html

- Breakage in libgit2: https://issuetracker.google.com/issues/189629152
(on Android public issue tracker, requires login)

Second, we now cache decrypted symlink targets in ->i_link. Therefore, taking the performance hit of reading and decrypting the symlink target in ->getattr() wouldn't be as big a deal as it used to be, since usually it will just save having to do the same thing later.

Also note that eCryptfs ended up having to read and decrypt symlink targets in ->getattr() as well, to fix this same issue; see commit 3a60a1686f0d ("eCryptfs: Decrypt symlink target for stat size").

So, let's just bite the bullet, and read and decrypt the symlink target in ->getattr() in order to report the correct st_size. Add a function fscrypt_symlink_getattr() which the filesystems will call to do this.

(Alternatively, we could store the decrypted size of symlinks on-disk. But there isn't a great place to do so, and encryption is meant to hide the original size to some extent; that property would be lost.)

---
 fs/crypto/hooks.c       |   44 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/fscrypt.h |    7 +++++++
 2 files changed, 51 insertions(+)

@@ -384,3 +384,47 @@ err_kfree:
 	return ERR_PTR(err);
 }
 EXPORT_SYMBOL_GPL(fscrypt_get_symlink);
+
+/**
+ * fscrypt_symlink_getattr() - set the correct st_size for encrypted symlinks
+ * @path: the path for the encrypted symlink being queried
+ * @stat: the struct being filled with the symlink's attributes
+ *
+ * Override st_size of encrypted symlinks to be the length of the decrypted
+ * symlink target (or the no-key encoded symlink target, if the key is
+ * unavailable) rather than the length of the encrypted symlink target.  This is
+ * necessary for st_size to match the symlink target that userspace actually
+ * sees.  POSIX requires this, and some userspace programs depend on it.
+ *
+ * This requires reading the symlink target from disk if needed, setting up the
+ * inode's encryption key if possible, and then decrypting or encoding the
+ * symlink target.  This makes lstat() more heavyweight than is normally the
+ * case.  However, decrypted symlink targets will be cached in ->i_link, so
+ * usually the symlink won't have to be read and decrypted again later if/when
+ * it is actually followed, readlink() is called, or lstat() is called again.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int fscrypt_symlink_getattr(const struct path *path, struct kstat *stat)
+{
+	struct dentry *dentry = path->dentry;
+	struct inode *inode = d_inode(dentry);
+	const char *link;
+	DEFINE_DELAYED_CALL(done);
+
+	/*
+	 * To get the symlink target that userspace will see (whether it's the
+	 * decrypted target or the no-key encoded target), we can just get it in
+	 * the same way the VFS does during path resolution and readlink().
+	 */
+	link = READ_ONCE(inode->i_link);
+	if (!link) {
+		link = inode->i_op->get_link(dentry, inode, &done);
+		if (IS_ERR(link))
+			return PTR_ERR(link);
+	}
+	stat->size = strlen(link);
+	do_delayed_call(&done);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(fscrypt_symlink_getattr);

@@ -253,6 +253,7 @@ int __fscrypt_encrypt_symlink(struct ino
 const char *fscrypt_get_symlink(struct inode *inode, const void *caddr,
 				unsigned int max_size,
 				struct delayed_call *done);
+int fscrypt_symlink_getattr(const struct path *path, struct kstat *stat);
 static inline void fscrypt_set_ops(struct super_block *sb,
 				   const struct fscrypt_operations *s_cop)
 {

@@ -583,6 +584,12 @@ static inline const char *fscrypt_get_sy
 	return ERR_PTR(-EOPNOTSUPP);
 }
 
+static inline int fscrypt_symlink_getattr(const struct path *path,
+					  struct kstat *stat)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline void fscrypt_set_ops(struct super_block *sb,
 				   const struct fscrypt_operations *s_cop)
 {

From: Eric Biggers <[email protected]>

commit 8c4bca10ceafc43b1ca0a9fab5fa27e13cbce99e upstream.

The stat() family of syscalls report the wrong size for encrypted symlinks, which has caused breakage in several userspace programs.

Fix this by calling fscrypt_symlink_getattr() after ext4_getattr() for encrypted symlinks. This function computes the correct size by reading and decrypting the symlink target (if it's not already cached).

For more details, see the commit which added fscrypt_symlink_getattr().

---
 fs/ext4/symlink.c |   12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

@@ -52,10 +52,20 @@ static const char *ext4_encrypted_get_li
 	return paddr;
 }
 
+static int ext4_encrypted_symlink_getattr(struct user_namespace *mnt_userns,
+					  const struct path *path,
+					  struct kstat *stat, u32 request_mask,
+					  unsigned int query_flags)
+{
+	ext4_getattr(mnt_userns, path, stat, request_mask, query_flags);
+
+	return fscrypt_symlink_getattr(path, stat);
+}
+
 const struct inode_operations ext4_encrypted_symlink_inode_operations = {
 	.get_link	= ext4_encrypted_get_link,
 	.setattr	= ext4_setattr,
-	.getattr	= ext4_getattr,
+	.getattr	= ext4_encrypted_symlink_getattr,
 	.listxattr	= ext4_listxattr,
 };
 

From: Eric Biggers <[email protected]>

commit 461b43a8f92e68e96c4424b31e15f2b35f1bbfa9 upstream.

The stat() family of syscalls report the wrong size for encrypted symlinks, which has caused breakage in several userspace programs.

Fix this by calling fscrypt_symlink_getattr() after f2fs_getattr() for encrypted symlinks. This function computes the correct size by reading and decrypting the symlink target (if it's not already cached).

For more details, see the commit which added fscrypt_symlink_getattr().

---
 fs/f2fs/namei.c |   12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

@@ -1323,9 +1323,19 @@ static const char *f2fs_encrypted_get_li
 	return target;
 }
 
+static int f2fs_encrypted_symlink_getattr(struct user_namespace *mnt_userns,
+					  const struct path *path,
+					  struct kstat *stat, u32 request_mask,
+					  unsigned int query_flags)
+{
+	f2fs_getattr(mnt_userns, path, stat, request_mask, query_flags);
+
+	return fscrypt_symlink_getattr(path, stat);
+}
+
 const struct inode_operations f2fs_encrypted_symlink_inode_operations = {
 	.get_link	= f2fs_encrypted_get_link,
-	.getattr	= f2fs_getattr,
+	.getattr	= f2fs_encrypted_symlink_getattr,
 	.setattr	= f2fs_setattr,
 	.listxattr	= f2fs_listxattr,
 };

From: Eric Biggers <[email protected]>

commit 064c734986011390b4d111f1a99372b7f26c3850 upstream.

The stat() family of syscalls report the wrong size for encrypted symlinks, which has caused breakage in several userspace programs.

Fix this by calling fscrypt_symlink_getattr() after ubifs_getattr() for encrypted symlinks. This function computes the correct size by reading and decrypting the symlink target (if it's not already cached).

For more details, see the commit which added fscrypt_symlink_getattr().

---
 fs/ubifs/file.c |   13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

@@ -1630,6 +1630,17 @@ static const char *ubifs_get_link(struct
 	return fscrypt_get_symlink(inode, ui->data, ui->data_len, done);
 }
 
+static int ubifs_symlink_getattr(struct user_namespace *mnt_userns,
+				 const struct path *path, struct kstat *stat,
+				 u32 request_mask, unsigned int query_flags)
+{
+	ubifs_getattr(mnt_userns, path, stat, request_mask, query_flags);
+
+	if (IS_ENCRYPTED(d_inode(path->dentry)))
+		return fscrypt_symlink_getattr(path, stat);
+	return 0;
+}
+
 const struct address_space_operations ubifs_file_address_operations = {
 	.readpage       = ubifs_readpage,
 	.writepage      = ubifs_writepage,

@@ -1655,7 +1666,7 @@ const struct inode_operations ubifs_file
 const struct inode_operations ubifs_symlink_inode_operations = {
 	.get_link    = ubifs_get_link,
 	.setattr     = ubifs_setattr,
-	.getattr     = ubifs_getattr,
+	.getattr     = ubifs_symlink_getattr,
 	.listxattr   = ubifs_listxattr,
 	.update_time = ubifs_update_time,
 };

From: Peter Collingbourne <[email protected]>

commit d0efb16294d145d157432feda83877ae9d7cdf37 upstream.

A common implementation of isatty(3) involves calling a ioctl passing a dummy struct argument and checking whether the syscall failed -- bionic and glibc use TCGETS (passing a struct termios), and musl uses TIOCGWINSZ (passing a struct winsize). If the FD is a socket, we will copy sizeof(struct ifreq) bytes of data from the argument and return -EFAULT if that fails. The result is that the isatty implementations may return a non-POSIX-compliant value in errno in the case where part of the dummy struct argument is inaccessible, as both struct termios and struct winsize are smaller than struct ifreq (at least on arm64).

Although there is usually enough stack space following the argument on the stack that this did not present a practical problem up to now, with MTE stack instrumentation it's more likely for the copy to fail, as the memory following the struct may have a different tag.

Fix the problem by adding an early check for whether the ioctl is a valid socket ioctl, and return -ENOTTY if it isn't.

---
 include/linux/netdevice.h |    4 ++++
 net/socket.c              |    6 +++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

@@ -4012,6 +4012,10 @@ int netdev_rx_handler_register(struct ne
 void netdev_rx_handler_unregister(struct net_device *dev);
 
 bool dev_valid_name(const char *name);
+static inline bool is_socket_ioctl_cmd(unsigned int cmd)
+{
+	return _IOC_TYPE(cmd) == SOCK_IOC_TYPE;
+}
 int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr,
 		bool *need_copyout);
 int dev_ifconf(struct net *net, struct ifconf *, int);

@@ -1109,7 +1109,7 @@ static long sock_do_ioctl(struct net *ne
 		rtnl_unlock();
 		if (!err && copy_to_user(argp, &ifc, sizeof(struct ifconf)))
 			err = -EFAULT;
-	} else {
+	} else if (is_socket_ioctl_cmd(cmd)) {
 		struct ifreq ifr;
 		bool need_copyout;
 		if (copy_from_user(&ifr, argp, sizeof(struct ifreq)))

@@ -1118,6 +1118,8 @@ static long sock_do_ioctl(struct net *ne
 		if (!err && need_copyout)
 			if (copy_to_user(argp, &ifr, sizeof(struct ifreq)))
 				return -EFAULT;
+	} else {
+		err = -ENOTTY;
 	}
 	return err;
 }

@@ -3306,6 +3308,8 @@ static int compat_ifr_data_ioctl(struct
 	struct ifreq ifreq;
 	u32 data32;
 
+	if (!is_socket_ioctl_cmd(cmd))
+		return -ENOTTY;
 	if (copy_from_user(ifreq.ifr_name, u_ifreq32->ifr_name, IFNAMSIZ))
 		return -EFAULT;
 	if (get_user(data32, &u_ifreq32->ifr_data))

From: Richard Guy Briggs <[email protected]>

commit 67d69e9d1a6c889d98951c1d74b19332ce0565af upstream.

AUDIT_TRIM is expected to be idempotent, but multiple executions resulted in a refcount underflow and use-after-free.

git bisect fingered commit fb041bb7c0a9 ("locking/refcount: Consolidate
implementations of refcount_t") but this patch with its more thorough checking that wasn't in the x86 assembly code merely exposed a previously existing tree refcount imbalance in the case of tree trimming code that was refactored with prune_one() to remove a tree introduced in commit 8432c7006297 ("audit: Simplify locking around untag_chunk()")

Move the put_tree() to cover only the prune_one() case.

Passes audit-testsuite and 3 passes of "auditctl -t" with at least one directory watch.

---
 kernel/audit_tree.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -593,7 +593,6 @@ static void prune_tree_chunks(struct aud
 		spin_lock(&hash_lock);
 	}
 	spin_unlock(&hash_lock);
-	put_tree(victim);
 }
 
 /*

@@ -602,6 +601,7 @@ static void prune_tree_chunks(struct aud
 static void prune_one(struct audit_tree *victim)
 {
 	prune_tree_chunks(victim, false);
+	put_tree(victim);
 }
 
 /* trim the uncommitted chunks from tree */

5.14.1-rc1 Successfully Compiled and booted on my Raspberry PI 4b (8g) (bcm2711)

All tests passing for Tegra ...

Test results for stable-v5.14:

    10 builds:	10 pass, 0 fail
    28 boots:	28 pass, 0 fail
    114 tests:	114 pass, 0 fail

Linux version: 5.14.1-rc1-g95dc72bb9c03
Boards tested: tegra124-jetson-tk1, tegra186-p2771-0000,

                tegra194-p2972-0000, tegra194-p3509-0000+p3668-0000,
                tegra20-ventana, tegra210-p2371-2180,
                tegra210-p3450-0000, tegra30-cardhu-a04

Jon

Compiled and booted on my test system. No dmesg regressions.

thanks,
-- Shuah

Results from Linaro’s test farm.
No regressions on arm64, arm, x86_64, and i386.

## Build
* kernel: 5.14.1-rc1
* git: https://gitlab.com/Linaro/lkft/mirrors/stable/linux-stable-rc
* git branch: linux-5.14.y
* git commit: 95dc72bb9c032093e79e628a98c927b3db73a6c3
* git describe: v5.14-rc6-389-g95dc72bb9c03
* test details:
https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-5.14.y/build/v5.14-rc6-389-g95dc72bb9c03

## No regressions (compared to v5.14)

## No fixes (compared to v5.14)

## Test result summary
total: 87243, pass: 73125, fail: 1909, skip: 12209, xfail: 931

## Build Summary
* arc: 10 total, 10 passed, 0 failed
* arm: 258 total, 258 passed, 0 failed
* arm64: 36 total, 36 passed, 0 failed
* dragonboard-410c: 1 total, 1 passed, 0 failed
* hi6220-hikey: 1 total, 1 passed, 0 failed
* i386: 35 total, 35 passed, 0 failed
* juno-r2: 1 total, 1 passed, 0 failed
* mips: 51 total, 51 passed, 0 failed
* parisc: 9 total, 9 passed, 0 failed
* powerpc: 27 total, 27 passed, 0 failed
* riscv: 27 total, 27 passed, 0 failed
* s390: 24 total, 24 passed, 0 failed
* sh: 18 total, 18 passed, 0 failed
* sparc: 9 total, 9 passed, 0 failed
* x15: 1 total, 0 passed, 1 failed
* x86: 1 total, 1 passed, 0 failed
* x86_64: 36 total, 36 passed, 0 failed

## Test suites summary
* fwts
* igt-gpu-tools
* install-android-platform-tools-r2600
* kselftest-android
* kselftest-arm64
* kselftest-arm64/arm64.btitest.bti_c_func
* kselftest-arm64/arm64.btitest.bti_j_func
* kselftest-arm64/arm64.btitest.bti_jc_func
* kselftest-arm64/arm64.btitest.bti_none_func
* kselftest-arm64/arm64.btitest.nohint_func
* kselftest-arm64/arm64.btitest.paciasp_func
* kselftest-arm64/arm64.nobtitest.bti_c_func
* kselftest-arm64/arm64.nobtitest.bti_j_func
* kselftest-arm64/arm64.nobtitest.bti_jc_func
* kselftest-arm64/arm64.nobtitest.bti_none_func
* kselftest-arm64/arm64.nobtitest.nohint_func
* kselftest-arm64/arm64.nobtitest.paciasp_func
* kselftest-bpf
* kselftest-breakpoints
* kselftest-capabilities
* kselftest-cgroup
* kselftest-clone3
* kselftest-core
* kselftest-cpu-hotplug
* kselftest-cpufreq
* kselftest-drivers
* kselftest-efivarfs
* kselftest-filesystems
* kselftest-firmware
* kselftest-fpu
* kselftest-futex
* kselftest-gpio
* kselftest-intel_pstate
* kselftest-ipc
* kselftest-ir
* kselftest-kcmp
* kselftest-kexec
* kselftest-kvm
* kselftest-lib
* kselftest-livepatch
* kselftest-lkdtm
* kselftest-membarrier
* kselftest-memfd
* kselftest-memory-hotplug
* kselftest-mincore
* kselftest-mount
* kselftest-mqueue
* kselftest-net
* kselftest-netfilter
* kselftest-nsfs
* kselftest-openat2
* kselftest-pid_namespace
* kselftest-pidfd
* kselftest-proc
* kselftest-pstore
* kselftest-ptrace
* kselftest-rseq
* kselftest-rtc
* kselftest-seccomp
* kselftest-sigaltstack
* kselftest-size
* kselftest-splice
* kselftest-static_keys
* kselftest-sync
* kselftest-sysctl
* kselftest-tc-testing
* kselftest-timens
* kselftest-timers
* kselftest-tmpfs
* kselftest-tpm2
* kselftest-user
* kselftest-vm
* kselftest-x86
* kselftest-zram
* kunit
* kvm-unit-tests
* libgpiod
* libhugetlbfs
* linux-log-parser
* ltp-cap_bounds-tests
* ltp-commands-tests
* ltp-containers-tests
* ltp-controllers-tests
* ltp-cpuhotplug-tests
* ltp-crypto-tests
* ltp-cve-tests
* ltp-dio-tests
* ltp-fcntl-locktests-tests
* ltp-filecaps-tests
* ltp-fs-tests
* ltp-fs_bind-tests
* ltp-fs_perms_simple-tests
* ltp-fsx-tests
* ltp-hugetlb-tests
* ltp-io-tests
* ltp-ipc-tests
* ltp-math-tests
* ltp-mm-tests
* ltp-nptl-tests
* ltp-open-posix-tests
* ltp-pty-tests
* ltp-sched-tests
* ltp-securebits-tests
* ltp-syscalls-tests
* ltp-tracing-tests
* network-basic-tests
* packetdrill
* perf
* rcutorture
* ssuite
* v4l2-compliance

--
Linaro LKFT
https://lkft.linaro.org

Build results:

	total: 154 pass: 154 fail: 0
Qemu test results:
	total: 479 pass: 479 fail: 0

Guenter

On ARCH_BRCMSTB using 32-bit and 64-bit ARM kernels:

--
Florian