slab memory leak (size-32)

[stanojr]

hello,
today i found on some servers with grsec that they missing lots of ram
i use 2.6.24.7-grsec with latest official grsecurity-2.1.11-2.6.24.5-200804211829.patch.gz

there is 16GB of ram an when i run slabtop
OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
194525744 194525692 11% 0.03K 1736837 112 6947348K size-32
1093792 920457 84% 0.50K 156256 7 625024K xfs_inode
1090159 920428 84% 0.56K 155737 7 622948K xfs_vnode

so size-32 eat 7gb of ram (uptime 134 days)

i have another server (different hw) with 2.6.24.3-grsec and older grsecurity-2.1.11-2.6.24.3-200803031942.patch
7gb of ram uptime 207 days and slabtop:
OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
74144896 74144836 42% 0.03K 662008 112 2648032K size-32

(i have one more machine with different hw(opteron) with 7 days uptime and size-32 eats 151MB)

can this be grsec/pax bug ?

[PaX Team]

so size-32 eat 7gb of ram (uptime 134 days)

that's not good... i wonder if you could determine what kind of data is leaked into those small allocations, maybe by dumping /dev/mem you could see a pattern. also, would be nice if you could test a somewhat newer kernel, grsec is at .26 already and spender's almost finished .27 as well.