git: 862d2d514cb7 - stable/13 - sockets: re-check socket state after call to pr_rcvd()

The branch stable/13 has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=862d2d514cb782353bce1af99d670db08b1e6c3c

commit 862d2d514cb782353bce1af99d670db08b1e6c3c
Author:     Greg Becker <becker.greg@att.net>
AuthorDate: 2023-09-09 23:38:24 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2023-09-27 12:33:08 +0000

    sockets: re-check socket state after call to pr_rcvd()
    
    Socket state may have changed after dropping the receive
    buffer lock in order to call pr_rcvd().  If the buffer is
    empty, re-check the state after reaquiring the lock and
    skip calling sbwait() if the socket is in error or the
    peer has closed.
    
    PR:             212716
    Reviewed by:    markj, glebius
    MFC after:      1 week
    Differential Revision:  https://reviews.freebsd.org/D41783
    
    (cherry picked from commit f44102411e1b16363e91a074c9c403069c550e4d)
---
 sys/kern/uipc_socket.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
index a4623329e686..e5997e439964 100644
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -2326,6 +2326,10 @@ dontblock:
 				VNET_SO_ASSERT(so);
 				(*pr->pr_usrreqs->pru_rcvd)(so, flags);
 				SOCKBUF_LOCK(&so->so_rcv);
+				if (__predict_false(so->so_rcv.sb_mb == NULL &&
+				    (so->so_error || so->so_rerror ||
+				    so->so_rcv.sb_state & SBS_CANTRCVMORE)))
+					break;
 			}
 			SBLASTRECORDCHK(&so->so_rcv);
 			SBLASTMBUFCHK(&so->so_rcv);