[PATCH 2/2] SUNRPC: Fix infinite looping in rpc_clnt_iterate_for_each_xprt
From: Xiaohui Zhang <hidden>
Date: 2022-06-04 03:28:51
Also in:
linux-nfs, lkml
Subsystem:
kernel nfsd, sunrpc, and lockd servers, networking [general], nfs, sunrpc, and lockd clients, the rest · Maintainers:
Chuck Lever, Jeff Layton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Trond Myklebust, Anna Schumaker, Linus Torvalds
From: hifoolno <redacted> If there were less than 2 entries in the multipath list, then xprt_iter_current_entry() 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. Signed-off-by: hifoolno <redacted> --- net/sunrpc/xprtmultipath.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/net/sunrpc/xprtmultipath.c b/net/sunrpc/xprtmultipath.c
index 1693f81aae37..23c3aae1bb5b 100644
--- a/net/sunrpc/xprtmultipath.c
+++ b/net/sunrpc/xprtmultipath.c@@ -278,14 +278,12 @@ static struct rpc_xprt *xprt_iter_current_entry(struct rpc_xprt_iter *xpi) { 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 (xpi->xpi_cursor == NULL || xps->xps_nxprts < 2) - return xprt_switch_find_first_entry(head); - return xprt_switch_find_current_entry(head, xpi->xpi_cursor); + return xprt_switch_set_next_cursor(&xps->xps_xprt_list, + &xpi->xpi_cursor, + find_next); } bool rpc_xprt_switch_has_addr(struct rpc_xprt_switch *xps,
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2.17.1