| Date | Sun, 09 Sep 2012 23:42:56 +0100 | From | Ben Hutchings <> | Subject | [ 66/95] svcrpc: fix BUG() in svc_tcp_clear_pages |
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3.2-stable review patch. If anyone has any objections, please let me know.
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From: "J. Bruce Fields" <bfields@redhat.com>
commit be1e44441a560c43c136a562d49a1c9623c91197 upstream.
Examination of svc_tcp_clear_pages shows that it assumes sk_tcplen is consistent with sk_pages[] (in particular, sk_pages[n] can't be NULL if sk_tcplen would lead us to expect n pages of data).
svc_tcp_restore_pages zeroes out sk_pages[] while leaving sk_tcplen. This is OK, since both functions are serialized by XPT_BUSY. However, that means the inconsistency must be repaired before dropping XPT_BUSY.
Therefore we should be ensuring that svc_tcp_save_pages repairs the problem before exiting svc_tcp_recv_record on error.
Symptoms were a BUG() in svc_tcp_clear_pages.
Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- net/sunrpc/svcsock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 18bc130..998aa8c 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -1129,9 +1129,9 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp) if (len >= 0) svsk->sk_tcplen += len; if (len != want) { + svc_tcp_save_pages(svsk, rqstp); if (len < 0 && len != -EAGAIN) goto err_other; - svc_tcp_save_pages(svsk, rqstp); dprintk("svc: incomplete TCP record (%d of %d)\n", svsk->sk_tcplen, svsk->sk_reclen); goto err_noclose;
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