From ebed9203b68a4f333ce5d17e874b26c3afcfeff1 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 2 Mar 2010 13:06:22 -0500 Subject: [PATCH] NFS: Fix an allocation-under-spinlock bug sunrpc_cache_update() will always call detail->update() from inside the detail->hash_lock, so it cannot allocate memory. Signed-off-by: Trond Myklebust Cc: stable@kernel.org --- fs/nfs/dns_resolve.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/fs/nfs/dns_resolve.c b/fs/nfs/dns_resolve.c index 95e1ca765d4..3f0cd4dfdda 100644 --- a/fs/nfs/dns_resolve.c +++ b/fs/nfs/dns_resolve.c @@ -36,6 +36,19 @@ struct nfs_dns_ent { }; +static void nfs_dns_ent_update(struct cache_head *cnew, + struct cache_head *ckey) +{ + struct nfs_dns_ent *new; + struct nfs_dns_ent *key; + + new = container_of(cnew, struct nfs_dns_ent, h); + key = container_of(ckey, struct nfs_dns_ent, h); + + memcpy(&new->addr, &key->addr, key->addrlen); + new->addrlen = key->addrlen; +} + static void nfs_dns_ent_init(struct cache_head *cnew, struct cache_head *ckey) { @@ -49,8 +62,7 @@ static void nfs_dns_ent_init(struct cache_head *cnew, new->hostname = kstrndup(key->hostname, key->namelen, GFP_KERNEL); if (new->hostname) { new->namelen = key->namelen; - memcpy(&new->addr, &key->addr, key->addrlen); - new->addrlen = key->addrlen; + nfs_dns_ent_update(cnew, ckey); } else { new->namelen = 0; new->addrlen = 0; @@ -234,7 +246,7 @@ static struct cache_detail nfs_dns_resolve = { .cache_show = nfs_dns_show, .match = nfs_dns_match, .init = nfs_dns_ent_init, - .update = nfs_dns_ent_init, + .update = nfs_dns_ent_update, .alloc = nfs_dns_ent_alloc, }; -- 2.11.4.GIT