linux-stable.git/fs, branch v6.3.3

ext4: fix invalid free tracking in ext4_xattr_move_to_block()

2023-05-17T12:02:07+00:00

commit b87c7cdf2bed4928b899e1ce91ef0d147017ba45 upstream.

In ext4_xattr_move_to_block(), the value of the extended attribute
which we need to move to an external block may be allocated by
kvmalloc() if the value is stored in an external inode.  So at the end
of the function the code tried to check if this was the case by
testing entry->e_value_inum.

However, at this point, the pointer to the xattr entry is no longer
valid, because it was removed from the original location where it had
been stored.  So we could end up calling kvfree() on a pointer which
was not allocated by kvmalloc(); or we could also potentially leak
memory by not freeing the buffer when it should be freed.  Fix this by
storing whether it should be freed in a separate variable.

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230430160426.581366-1-tytso@mit.edu
Link: https://syzkaller.appspot.com/bug?id=5c2aee8256e30b55ccf57312c16d88417adbd5e1
Link: https://syzkaller.appspot.com/bug?id=41a6b5d4917c0412eb3b3c3c604965bed7d7420b
Reported-by: syzbot+64b645917ce07d89bde5@syzkaller.appspotmail.com
Reported-by: syzbot+0d042627c4f2ad332195@syzkaller.appspotmail.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: remove a BUG_ON in ext4_mb_release_group_pa()

2023-05-17T12:02:07+00:00

commit 463808f237cf73e98a1a45ff7460c2406a150a0b upstream.

If a malicious fuzzer overwrites the ext4 superblock while it is
mounted such that the s_first_data_block is set to a very large
number, the calculation of the block group can underflow, and trigger
a BUG_ON check.  Change this to be an ext4_warning so that we don't
crash the kernel.

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230430154311.579720-3-tytso@mit.edu
Reported-by: syzbot+e2efa3efc15a1c9e95c3@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=69b28112e098b070f639efb356393af3ffec4220
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: fix lockdep warning when enabling MMP

2023-05-17T12:02:07+00:00

commit 949f95ff39bf188e594e7ecd8e29b82eb108f5bf upstream.

When we enable MMP in ext4_multi_mount_protect() during mount or
remount, we end up calling sb_start_write() from write_mmp_block(). This
triggers lockdep warning because freeze protection ranks above s_umount
semaphore we are holding during mount / remount. The problem is harmless
because we are guaranteed the filesystem is not frozen during mount /
remount but still let's fix the warning by not grabbing freeze
protection from ext4_multi_mount_protect().

Cc: stable@kernel.org
Reported-by: syzbot+6b7df7d5506b32467149@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=ab7e5b6f400b7778d46f01841422e5718fb81843
Signed-off-by: Jan Kara 
Reviewed-by: Christian Brauner 
Link: https://lore.kernel.org/r/20230411121019.21940-1-jack@suse.cz
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: bail out of ext4_xattr_ibody_get() fails for any reason

2023-05-17T12:02:07+00:00

commit 2a534e1d0d1591e951f9ece2fb460b2ff92edabd upstream.

In ext4_update_inline_data(), if ext4_xattr_ibody_get() fails for any
reason, it's best if we just fail as opposed to stumbling on,
especially if the failure is EFSCORRUPTED.

Cc: stable@kernel.org
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: add bounds checking in get_max_inline_xattr_value_size()

2023-05-17T12:02:07+00:00

commit 2220eaf90992c11d888fe771055d4de330385f01 upstream.

Normally the extended attributes in the inode body would have been
checked when the inode is first opened, but if someone is writing to
the block device while the file system is mounted, it's possible for
the inode table to get corrupted.  Add bounds checking to avoid
reading beyond the end of allocated memory if this happens.

Reported-by: syzbot+1966db24521e5f6e23f7@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=1966db24521e5f6e23f7
Cc: stable@kernel.org
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: fix deadlock when converting an inline directory in nojournal mode

2023-05-17T12:02:07+00:00

commit f4ce24f54d9cca4f09a395f3eecce20d6bec4663 upstream.

In no journal mode, ext4_finish_convert_inline_dir() can self-deadlock
by calling ext4_handle_dirty_dirblock() when it already has taken the
directory lock.  There is a similar self-deadlock in
ext4_incvert_inline_data_nolock() for data files which we'll fix at
the same time.

A simple reproducer demonstrating the problem:

    mke2fs -Fq -t ext2 -O inline_data -b 4k /dev/vdc 64
    mount -t ext4 -o dirsync /dev/vdc /vdc
    cd /vdc
    mkdir file0
    cd file0
    touch file0
    touch file1
    attr -s BurnSpaceInEA -V abcde .
    touch supercalifragilisticexpialidocious

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230507021608.1290720-1-tytso@mit.edu
Reported-by: syzbot+91dccab7c64e2850a4e5@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=ba84cc80a9491d65416bc7877e1650c87530fe8a
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: improve error handling from ext4_dirhash()

2023-05-17T12:02:06+00:00

commit 4b3cb1d108bfc2aebb0d7c8a52261a53cf7f5786 upstream.

The ext4_dirhash() will *almost* never fail, especially when the hash
tree feature was first introduced.  However, with the addition of
support of encrypted, casefolded file names, that function can most
certainly fail today.

So make sure the callers of ext4_dirhash() properly check for
failures, and reflect the errors back up to their callers.

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230506142419.984260-1-tytso@mit.edu
Reported-by: syzbot+394aa8a792cb99dbc837@syzkaller.appspotmail.com
Reported-by: syzbot+344aaa8697ebd232bfc8@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=db56459ea4ac4a676ae4b4678f633e55da005a9b
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: improve error recovery code paths in __ext4_remount()

2023-05-17T12:02:06+00:00

commit 4c0b4818b1f636bc96359f7817a2d8bab6370162 upstream.

If there are failures while changing the mount options in
__ext4_remount(), we need to restore the old mount options.

This commit fixes two problem.  The first is there is a chance that we
will free the old quota file names before a potential failure leading
to a use-after-free.  The second problem addressed in this commit is
if there is a failed read/write to read-only transition, if the quota
has already been suspended, we need to renable quota handling.

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230506142419.984260-2-tytso@mit.edu
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: check iomap type only if ext4_iomap_begin() does not fail

2023-05-17T12:02:06+00:00

commit fa83c34e3e56b3c672af38059e066242655271b1 upstream.

When ext4_iomap_overwrite_begin() calls ext4_iomap_begin() map blocks may
fail for some reason (e.g. memory allocation failure, bare disk write), and
later because "iomap->type ! = IOMAP_MAPPED" triggers WARN_ON(). When ext4
iomap_begin() returns an error, it is normal that the type of iomap->type
may not match the expectation. Therefore, we only determine if iomap->type
is as expected when ext4_iomap_begin() is executed successfully.

Cc: stable@kernel.org
Reported-by: syzbot+08106c4b7d60702dbc14@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/00000000000015760b05f9b4eee9@google.com
Signed-off-by: Baokun Li 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20230505132429.714648-1-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: avoid deadlock in fs reclaim with page writeback

2023-05-17T12:02:06+00:00

commit 00d873c17e29cc32d90ca852b82685f1673acaa5 upstream.

Ext4 has a filesystem wide lock protecting ext4_writepages() calls to
avoid races with switching of journalled data flag or inode format. This
lock can however cause a deadlock like:

CPU0                            CPU1

ext4_writepages()
  percpu_down_read(sbi->s_writepages_rwsem);
                                ext4_change_inode_journal_flag()
                                  percpu_down_write(sbi->s_writepages_rwsem);
                                    - blocks, all readers block from now on
  ext4_do_writepages()
    ext4_init_io_end()
      kmem_cache_zalloc(io_end_cachep, GFP_KERNEL)
        fs_reclaim frees dentry...
          dentry_unlink_inode()
            iput() - last ref =>
              iput_final() - inode dirty =>
                write_inode_now()...
                  ext4_writepages() tries to acquire sbi->s_writepages_rwsem
                    and blocks forever

Make sure we cannot recurse into filesystem reclaim from writeback code
to avoid the deadlock.

Reported-by: syzbot+6898da502aef574c5f8a@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/0000000000004c66b405fa108e27@google.com
Fixes: c8585c6fcaf2 ("ext4: fix races between changing inode journal mode and ext4_writepages")
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/r/20230504124723.20205-1-jack@suse.cz
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman