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author | Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> | 2013-04-30 00:08:39 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-04-30 00:54:38 +0200 |
commit | 7a6f93b0a873ad24631088c349e9d1ca3d4cf852 (patch) | |
tree | d824fc12bcd0c59fcee9cfc89f74f218bb51d594 /drivers/firmware | |
parent | mm/vmstat: add note on safety of drain_zonestat (diff) | |
download | linux-7a6f93b0a873ad24631088c349e9d1ca3d4cf852.tar.xz linux-7a6f93b0a873ad24631088c349e9d1ca3d4cf852.zip |
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: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Tang Chen <tangchen@cn.fujitsu.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/firmware')
-rw-r--r-- | drivers/firmware/memmap.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c index 0b5b5f619c75..e2e04b007e15 100644 --- a/drivers/firmware/memmap.c +++ b/drivers/firmware/memmap.c @@ -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; } |