Commit 7a6f93b0 authored by Yasuaki Ishimatsu's avatar Yasuaki Ishimatsu Committed by Linus Torvalds

firmware, memmap: fix firmware_map_entry leak

When hot removing memory, a firmware_map_entry which has memory range of
the memory is released by release_firmware_map_entry().  If the entry is
allocated by bootmem, release_firmware_map_entry() adds the entry to
map_entires_bootmem list when firmware_map_find_entry() finds the entry
from map_entries list.  But firmware_map_find_entry never find the entry
sicne map_entires list does not have the entry.  So the entry just
leaks.

Here are steps of leaking firmware_map_entry:
firmware_map_remove()
-> firmware_map_find_entry()
   Find released entry from map_entries list
-> firmware_map_remove_entry()
   Delete the entry from map_entries list
-> remove_sysfs_fw_map_entry()
   ...
   -> release_firmware_map_entry()
      -> firmware_map_find_entry()
         Find the entry from map_entries list but the entry has been
         deleted from map_entries list. So the entry is not added
         to map_entries_bootmem. Thus the entry leaks

release_firmware_map_entry() should not call firmware_map_find_entry()
since releaed entry has been deleted from map_entries list.  So the
patch delete firmware_map_find_entry() from releae_firmware_map_entry()
Signed-off-by: default avatarYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: default avatarWanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: default avatarTang Chen <tangchen@cn.fujitsu.com>
Acked-by: default avatarToshi Kani <toshi.kani@hp.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 40f4b1ea
......@@ -114,12 +114,9 @@ static void __meminit release_firmware_map_entry(struct kobject *kobj)
* map_entries_bootmem here, and deleted from &map_entries in
* firmware_map_remove_entry().
*/
if (firmware_map_find_entry(entry->start, entry->end,
entry->type)) {
spin_lock(&map_entries_bootmem_lock);
list_add(&entry->list, &map_entries_bootmem);
spin_unlock(&map_entries_bootmem_lock);
}
spin_lock(&map_entries_bootmem_lock);
list_add(&entry->list, &map_entries_bootmem);
spin_unlock(&map_entries_bootmem_lock);
return;
}
......
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