From: Linus Lüssing linus.luessing@c0d3.blue
Bitwise OR/AND assignments in C aren't guaranteed to be atomic. One OGM handler might undo the set/clear of a specific bit from another handler run in between.
Fix this by using the atomic set_bit()/clear_bit()/test_bit() functions.
Fixes: 17cf0ea455f1 ("batman-adv: tvlv - add distributed arp table container") Signed-off-by: Linus Lüssing linus.luessing@c0d3.blue Signed-off-by: Marek Lindner mareklindner@neomailbox.ch Signed-off-by: Antonio Quartulli antonio@meshcoding.com --- net/batman-adv/distributed-arp-table.c | 7 ++++--- net/batman-adv/types.h | 4 ++-- 2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index fb54e6a..244dcf6 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -19,6 +19,7 @@ #include "main.h"
#include <linux/atomic.h> +#include <linux/bitops.h> #include <linux/byteorder/generic.h> #include <linux/errno.h> #include <linux/etherdevice.h> @@ -453,7 +454,7 @@ static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res, int j;
/* check if orig node candidate is running DAT */ - if (!(candidate->capabilities & BATADV_ORIG_CAPA_HAS_DAT)) + if (!(test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities))) goto out;
/* Check if this node has already been selected... */ @@ -713,9 +714,9 @@ static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, uint16_t tvlv_value_len) { if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) - orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_DAT; + clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities); else - orig->capabilities |= BATADV_ORIG_CAPA_HAS_DAT; + set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities); }
/** diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 67d6348..29fd625 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -273,7 +273,7 @@ struct batadv_orig_node { struct hlist_node mcast_want_all_ipv4_node; struct hlist_node mcast_want_all_ipv6_node; #endif - uint8_t capabilities; + unsigned long capabilities; uint8_t capa_initialized; atomic_t last_ttvn; unsigned char *tt_buff; @@ -313,7 +313,7 @@ struct batadv_orig_node { * (= orig node announces a tvlv of type BATADV_TVLV_MCAST) */ enum batadv_orig_capabilities { - BATADV_ORIG_CAPA_HAS_DAT = BIT(0), + BATADV_ORIG_CAPA_HAS_DAT, BATADV_ORIG_CAPA_HAS_NC = BIT(1), BATADV_ORIG_CAPA_HAS_TT = BIT(2), BATADV_ORIG_CAPA_HAS_MCAST = BIT(3),