diff options
| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2010-09-12 19:55:25 -0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2010-09-12 19:55:25 -0400 |
| commit | 5a67657a2e90c9e4a48518f95d4ba7777aa20fbb (patch) | |
| tree | bd98ad7f5261afc7ae9ba804937d9ce2fb9e8764 /net/sunrpc/auth_gss | |
| parent | f2d47d02fd84343a3c5452daca6ed12c75618aff (diff) | |
SUNRPC: Fix race corrupting rpc upcall
If rpc_queue_upcall() adds a new upcall to the rpci->pipe list just
after rpc_pipe_release calls rpc_purge_list(), but before it calls
gss_pipe_release (as rpci->ops->release_pipe(inode)), then the latter
will free a message without deleting it from the rpci->pipe list.
We will be left with a freed object on the rpc->pipe list. Most
frequent symptoms are kernel crashes in rpc.gssd system calls on the
pipe in question.
Reported-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
Diffstat (limited to 'net/sunrpc/auth_gss')
| -rw-r--r-- | net/sunrpc/auth_gss/auth_gss.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c index dcfc66bab2b..12c48598281 100644 --- a/net/sunrpc/auth_gss/auth_gss.c +++ b/net/sunrpc/auth_gss/auth_gss.c @@ -745,17 +745,18 @@ gss_pipe_release(struct inode *inode) struct rpc_inode *rpci = RPC_I(inode); struct gss_upcall_msg *gss_msg; +restart: spin_lock(&inode->i_lock); - while (!list_empty(&rpci->in_downcall)) { + list_for_each_entry(gss_msg, &rpci->in_downcall, list) { - gss_msg = list_entry(rpci->in_downcall.next, - struct gss_upcall_msg, list); + if (!list_empty(&gss_msg->msg.list)) + continue; gss_msg->msg.errno = -EPIPE; atomic_inc(&gss_msg->count); __gss_unhash_msg(gss_msg); spin_unlock(&inode->i_lock); gss_release_msg(gss_msg); - spin_lock(&inode->i_lock); + goto restart; } spin_unlock(&inode->i_lock); |