ns2_fr: Fix heap-use-after-free in error recovery path
<0026> gprs_ns2_fr.c:515 BIND(hdlcnet1) Can not create AF_PACKET socket. Are you root or have CAP_NET_RAW?
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==3872359==ERROR: AddressSanitizer: heap-use-after-free on address 0x6130000030c0 at pc 0x7fef120aa92e bp 0x7ffebf6b5c20 sp 0x7ffebf6b5c18
READ of size 8 at 0x6130000030c0 thread T0
#0 0x7fef120aa92d in osmo_fr_link_free (/usr/local/lib/libosmogb.so.11+0x16992d)
#1 0x7fef1205105a in free_bind (/usr/local/lib/libosmogb.so.11+0x11005a)
Change-Id: I23c0f1697edd5734085fa18b0a2f253c0f206c53
diff --git a/src/gb/gprs_ns2_fr.c b/src/gb/gprs_ns2_fr.c
index 2df5986..7e6db2a 100644
--- a/src/gb/gprs_ns2_fr.c
+++ b/src/gb/gprs_ns2_fr.c
@@ -863,6 +863,7 @@
close(priv->backlog.ofd.fd);
err_fr:
osmo_fr_link_free(fr_link);
+ priv->link = NULL;
err_bind:
gprs_ns2_free_bind(bind);