[PATCH 4.7 143/143] SUNRPC: Fix infinite looping in rpc_clnt_iterate_for_each_xprt
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2016-09-05 16:58:15
Also in:
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4.7-stable review patch. If anyone has any objections, please let me know.
------------------
From: Trond Myklebust <redacted>
commit bdc54d8e3cb4a41dddcabfd86d9eb3aa5f622b75 upstream.
If there were less than 2 entries in the multipath list, then
xprt_iter_next_entry_multiple() would never advance beyond the
first entry, which is correct for round robin behaviour, but not
for the list iteration.
The end result would be infinite looping in rpc_clnt_iterate_for_each_xprt()
as we would never see the xprt == NULL condition fulfilled.
Reported-by: Oleg Drokin <redacted>
Fixes: 80b14d5e61ca ("SUNRPC: Add a structure to track multiple transports")
Signed-off-by: Trond Myklebust <redacted>
Cc: Jason L Tibbitts III <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/sunrpc/xprtmultipath.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
--- a/net/sunrpc/xprtmultipath.c
+++ b/net/sunrpc/xprtmultipath.c@@ -271,14 +271,12 @@ struct rpc_xprt *xprt_iter_next_entry_mu xprt_switch_find_xprt_t find_next) { struct rpc_xprt_switch *xps = rcu_dereference(xpi->xpi_xpswitch); - struct list_head *head; if (xps == NULL) return NULL; - head = &xps->xps_xprt_list; - if (xps->xps_nxprts < 2) - return xprt_switch_find_first_entry(head); - return xprt_switch_set_next_cursor(head, &xpi->xpi_cursor, find_next); + return xprt_switch_set_next_cursor(&xps->xps_xprt_list, + &xpi->xpi_cursor, + find_next); } static