From 9efcc4a129363187c9bf15338692f107c5c9b6f0 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 26 Mar 2020 15:24:07 +0000 Subject: afs: Fix unpinned address list during probing When it's probing all of a fileserver's interfaces to find which one is best to use, afs_do_probe_fileserver() takes a lock on the server record and notes the pointer to the address list. It doesn't, however, pin the address list, so as soon as it drops the lock, there's nothing to stop the address list from being freed under us. Fix this by taking a ref on the address list inside the locked section and dropping it at the end of the function. Fixes: 3bf0fb6f33dd ("afs: Probe multiple fileservers simultaneously") Signed-off-by: David Howells Reviewed-by: Marc Dionne Signed-off-by: Linus Torvalds --- fs/afs/fs_probe.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/afs/fs_probe.c b/fs/afs/fs_probe.c index cfe62b154f68..e1b9ed679045 100644 --- a/fs/afs/fs_probe.c +++ b/fs/afs/fs_probe.c @@ -145,6 +145,7 @@ static int afs_do_probe_fileserver(struct afs_net *net, read_lock(&server->fs_lock); ac.alist = rcu_dereference_protected(server->addresses, lockdep_is_held(&server->fs_lock)); + afs_get_addrlist(ac.alist); read_unlock(&server->fs_lock); atomic_set(&server->probe_outstanding, ac.alist->nr_addrs); @@ -163,6 +164,7 @@ static int afs_do_probe_fileserver(struct afs_net *net, if (!in_progress) afs_fs_probe_done(server); + afs_put_addrlist(ac.alist); return in_progress; } -- cgit