1. 12 Feb, 2019 37 commits
  2. 06 Feb, 2019 3 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.9.155 · 6ebe34c1
      Greg Kroah-Hartman authored
      6ebe34c1
    • Amir Goldstein's avatar
      fanotify: fix handling of events on child sub-directory · 987d8ff3
      Amir Goldstein authored
      commit b469e7e4 upstream.
      
      When an event is reported on a sub-directory and the parent inode has
      a mark mask with FS_EVENT_ON_CHILD|FS_ISDIR, the event will be sent to
      fsnotify() even if the event type is not in the parent mark mask
      (e.g. FS_OPEN).
      
      Further more, if that event happened on a mount or a filesystem with
      a mount/sb mark that does have that event type in their mask, the "on
      child" event will be reported on the mount/sb mark.  That is not
      desired, because user will get a duplicate event for the same action.
      
      Note that the event reported on the victim inode is never merged with
      the event reported on the parent inode, because of the check in
      should_merge(): old_fsn->inode == new_fsn->inode.
      
      Fix this by looking for a match of an actual event type (i.e. not just
      FS_ISDIR) in parent's inode mark mask and by not reporting an "on child"
      event to group if event type is only found on mount/sb marks.
      
      [backport hint: The bug seems to have always been in fanotify, but this
                      patch will only apply cleanly to v4.19.y]
      
      Cc: <stable@vger.kernel.org> # v4.19
      Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
      [amir: backport to v4.9]
      Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      987d8ff3
    • Dave Chinner's avatar
      fs: don't scan the inode cache before SB_BORN is set · d6f62ecb
      Dave Chinner authored
      commit 79f546a6 upstream.
      
      We recently had an oops reported on a 4.14 kernel in
      xfs_reclaim_inodes_count() where sb->s_fs_info pointed to garbage
      and so the m_perag_tree lookup walked into lala land.  It produces
      an oops down this path during the failed mount:
      
        radix_tree_gang_lookup_tag+0xc4/0x130
        xfs_perag_get_tag+0x37/0xf0
        xfs_reclaim_inodes_count+0x32/0x40
        xfs_fs_nr_cached_objects+0x11/0x20
        super_cache_count+0x35/0xc0
        shrink_slab.part.66+0xb1/0x370
        shrink_node+0x7e/0x1a0
        try_to_free_pages+0x199/0x470
        __alloc_pages_slowpath+0x3a1/0xd20
        __alloc_pages_nodemask+0x1c3/0x200
        cache_grow_begin+0x20b/0x2e0
        fallback_alloc+0x160/0x200
        kmem_cache_alloc+0x111/0x4e0
      
      The problem is that the superblock shrinker is running before the
      filesystem structures it depends on have been fully set up. i.e.
      the shrinker is registered in sget(), before ->fill_super() has been
      called, and the shrinker can call into the filesystem before
      fill_super() does it's setup work. Essentially we are exposed to
      both use-after-free and use-before-initialisation bugs here.
      
      To fix this, add a check for the SB_BORN flag in super_cache_count.
      In general, this flag is not set until ->fs_mount() completes
      successfully, so we know that it is set after the filesystem
      setup has completed. This matches the trylock_super() behaviour
      which will not let super_cache_scan() run if SB_BORN is not set, and
      hence will not allow the superblock shrinker from entering the
      filesystem while it is being set up or after it has failed setup
      and is being torn down.
      
      Cc: stable@kernel.org
      Signed-Off-By: default avatarDave Chinner <dchinner@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarAaron Lu <aaron.lu@linux.alibaba.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d6f62ecb