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authorVladimir Davydov <vdavydov@parallels.com>2014-01-23 15:53:01 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-23 16:36:51 -0800
commit96403da244443d9842dbf290c2a02390b78a158e (patch)
treeca3ccfc550f9c3ef0cf2baa634e784a6a66b3f73 /mm/slab_common.c
parent959c8963fc6c8c9b97e80c55ce77105247040e7d (diff)
memcg: fix possible NULL deref while traversing memcg_slab_caches list
All caches of the same memory cgroup are linked in the memcg_slab_caches list via kmem_cache::memcg_params::list. This list is traversed, for example, when we read memory.kmem.slabinfo. Since the list actually consists of memcg_cache_params objects, we have to convert an element of the list to a kmem_cache object using memcg_params_to_cache(), which obtains the pointer to the cache from the memcg_params::memcg_caches array of the corresponding root cache. That said the pointer to a kmem_cache in its parent's memcg_params must be initialized before adding the cache to the list, and cleared only after it has been unlinked. Currently it is vice-versa, which can result in a NULL ptr dereference while traversing the memcg_slab_caches list. This patch restores the correct order. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slab_common.c')
0 files changed, 0 insertions, 0 deletions