Merge tag 'vfs-7.2-rc6.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Merge tag 'vfs-7.2-rc6.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs fixes from Christian Brauner:
 "binfmt_misc:

   - Don't let an 'F' entry pin its own instance.

     An entry registered with 'F' opens its interpreter at registration
     time and holds that file until the entry is freed, so an entry
     nobody removes by hand is only closed once the binfmt_misc
     superblock is shut down.

     If the interpreter lives on a mount that keeps that superblock
     alive the two pin each other and the file is never closed. That's
     reachable by pointing the interpreter at the instance itself or by
     using the instance as an overlayfs lower layer, and once the mount
     namespace is gone there's nothing left to unregister through
     either.

   - Restore write access when removing an entry.

     Registering with the MISC_FMT_OPEN_FILE flag opens the interpreter
     via open_exec() which denies write access for as long as the entry
     exists, but removal only did filp_close() and never restored it.
     The inode's i_writecount stayed permanently negative and opening
     the interpreter for writing kept failing with ETXTBSY long after
     the entry was gone.

   - Use exe_file_deny_write_access() for the interpreter clone so both
     sides base their decision on the same mode.

   - Reject a flag character as the field delimiter. create_entry() pads
     the buffer with the delimiter so the field parsers terminate even
     on a truncated string, but check_special_flags() consumes flag
     characters instead of scanning for the delimiter.

     If the delimiter is itself a flag character the padding stops
     acting as a terminator and the scan keeps reading past the end of
     the allocation. Such a registration was always rejected, just only
     after the out of bounds read has already happened.

   - Don't leak the user namespace when the mount fails.

     bm_get_tree() hands its reference to get_tree_keyed() and sget_fc()
     moves it into sb->s_fs_info, but generic_shutdown_super() only
     calls ->put_super() from inside the if (sb->s_root) branch and
     bm_fill_super() can fail before either s_root or s_op is in place.

     Drop the reference in ->kill_sb() instead, which runs
     unconditionally.

  netfs:

   - Clear PG_private_2 on a copy-to-cache append failure.

   - Handle a rolling buffer allocation failure in single-object
     writeback and drop the extra folio reference
     netfs_write_folio_single() took before the append.

   - Release the previously batched readahead folios when
     rolling_buffer_load_from_ra() fails in
     netfs_prepare_read_iterator()

   - Fix the folio_queue ENOMEM in writeback by adding a mempool and
     passing gfp flags into the rolling buffer helpers.

  iomap:

   - Add a separate bio_set for iomap_split_ioend(). It can split bios
     that already come from iomap_ioend_bioset and deadlock once that
     bioset is exhausted.

  afs:

   - Set call->async for an asynchronous afs_fs_fetch_data() the way
     afs_fs_fetch_data64() already does.

   - Subtract subreq->transferred from subreq->len in
     afs_fs_fetch_data() rather than adding it.

   - Fix a UAF when sending a message"

* tag 'vfs-7.2-rc6.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  iomap: add a separate bio_set for iomap_split_ioend
  binfmt_misc: don't leak the user namespace when the mount fails
  binfmt_misc: reject a flag character as the field delimiter
  binfmt_misc: use exe_file_deny_write_access() for the interpreter clone
  binfmt_misc: restore write access when removing an entry
  binfmt_misc: don't let an 'F' entry pin its own instance
  netfs: Fix folio_queue ENOMEM in writeback by adding a mempool
  netfs: release readahead folios on iterator preparation failure
  netfs: handle single writeback rolling buffer allocation failure
  netfs: clear PG_private_2 on copy-to-cache append failure
  afs: Fix UAF when sending a message
  afs: Fix afs_fs_fetch_data() to subtract transferred from len
  afs: Fix afs_fs_fetch_data() to set call->async