From: Herbert Xu When we are not the real parent of the dst (e.g., when we're xfrm_dst and the child is an rtentry), it may already be on the GC list. In fact the current code is buggy to, we need to check dst->flags before the dec as dst may no longer be valid afterwards. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller Signed-off-by: Andrew Morton --- 25-akpm/net/core/dst.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff -puN net/core/dst.c~fix-dst_destroy-race net/core/dst.c --- 25/net/core/dst.c~fix-dst_destroy-race 2005-04-06 01:39:29.000000000 -0700 +++ 25-akpm/net/core/dst.c 2005-04-06 01:39:29.000000000 -0700 @@ -198,13 +198,15 @@ again: dst = child; if (dst) { + int nohash = dst->flags & DST_NOHASH; + if (atomic_dec_and_test(&dst->__refcnt)) { /* We were real parent of this dst, so kill child. */ - if (dst->flags&DST_NOHASH) + if (nohash) goto again; } else { /* Child is still referenced, return it for freeing. */ - if (dst->flags&DST_NOHASH) + if (nohash) return dst; /* Child is still in his hash table */ } _