[PATCH] rpc: fix garbage in printk in svc_tcp_accept()

From: J. Bruce Fields
Date: Thu Sep 20 2007 - 15:52:00 EST


we upgraded the kernel of a nfs-server from 2.6.17.11 to 2.6.22.6. Since
then we get the message

lockd: too many open TCP sockets, consider increasing the number of nfsd threads
lockd: last TCP connect from ^\\236^\Ã^D

These random characters in the second line are caused by a bug in
svc_tcp_accept.

(Note: there are two previous __svc_print_addr(sin, buf, sizeof(buf))
calls in this function, either of which would initialize buf correctly;
but both are inside "if"'s and are not necessarily executed. This is
less obvious in the second case, which is inside a dprintk(), which is a
macro which expands to an if statement.)

Signed-off-by: Wolfgang Walter <wolfgang.walter@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxxxxxx>
---
net/sunrpc/svcsock.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

We're printk'ing random uninitialized memory here, which I assume makes
it appropriate for both 2.6.23 and 2.6.22.x.--b.

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 1a89992..036ab52 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1110,7 +1110,8 @@ svc_tcp_accept(struct svc_sock *svsk)
serv->sv_name);
printk(KERN_NOTICE
"%s: last TCP connect from %s\n",
- serv->sv_name, buf);
+ serv->sv_name, __svc_print_addr(sin,
+ buf, sizeof(buf)));
}
/*
* Always select the oldest socket. It's not fair,
--
1.5.3.1.139.g9346b

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