[PATCH 4.16 254/279] afs: Fix afs_find_server search loop

From: Greg Kroah-Hartman
Date: Mon Jun 18 2018 - 05:22:55 EST


4.16-stable review patch. If anyone has any objections, please let me know.

------------------

From: Marc Dionne <marc.dionne@xxxxxxxxxxxx>

[ Upstream commit f9c1bba3d392843f046d2ee27b4dfcec989d8a4b ]

The code that looks up servers by addresses makes the assumption
that the list of addresses for a server is sorted. It exits the
loop if it finds that the target address is larger than the
current candidate. As the list is not currently sorted, this
can lead to a failure to find a matching server, which can cause
callbacks from that server to be ignored.

Remove the early exit case so that the complete list is searched.

Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/afs/server.c | 13 -------------
1 file changed, 13 deletions(-)

--- a/fs/afs/server.c
+++ b/fs/afs/server.c
@@ -66,12 +66,6 @@ struct afs_server *afs_find_server(struc
sizeof(struct in6_addr));
if (diff == 0)
goto found;
- if (diff < 0) {
- // TODO: Sort the list
- //if (i == alist->nr_ipv4)
- // goto not_found;
- break;
- }
}
}
} else {
@@ -85,17 +79,10 @@ struct afs_server *afs_find_server(struc
(u32)b->sin6_addr.s6_addr32[3]);
if (diff == 0)
goto found;
- if (diff < 0) {
- // TODO: Sort the list
- //if (i == 0)
- // goto not_found;
- break;
- }
}
}
}

- //not_found:
server = NULL;
found:
if (server && !atomic_inc_not_zero(&server->usage))