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: 3f4841ffb336 ("batman-adv: tvlv - add network coding 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/network-coding.c | 7 ++++--- net/batman-adv/types.h | 2 +- 2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c index f0a50f3..cfdc80d 100644 --- a/net/batman-adv/network-coding.c +++ b/net/batman-adv/network-coding.c @@ -19,6 +19,7 @@ #include "main.h"
#include <linux/atomic.h> +#include <linux/bitops.h> #include <linux/byteorder/generic.h> #include <linux/compiler.h> #include <linux/debugfs.h> @@ -134,9 +135,9 @@ static void batadv_nc_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_NC; + clear_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities); else - orig->capabilities |= BATADV_ORIG_CAPA_HAS_NC; + set_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities); }
/** @@ -894,7 +895,7 @@ void batadv_nc_update_nc_node(struct batadv_priv *bat_priv, goto out;
/* check if orig node is network coding enabled */ - if (!(orig_node->capabilities & BATADV_ORIG_CAPA_HAS_NC)) + if (!(test_bit(BATADV_ORIG_CAPA_HAS_NC, &orig_node->capabilities))) goto out;
/* accept ogms from 'good' neighbors and single hop neighbors */ diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 29fd625..ed4aec5 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -314,7 +314,7 @@ struct batadv_orig_node { */ enum batadv_orig_capabilities { BATADV_ORIG_CAPA_HAS_DAT, - BATADV_ORIG_CAPA_HAS_NC = BIT(1), + BATADV_ORIG_CAPA_HAS_NC, BATADV_ORIG_CAPA_HAS_TT = BIT(2), BATADV_ORIG_CAPA_HAS_MCAST = BIT(3), };