From: Arnd Bergmann Date: Thu, 11 Jun 2026 13:00:54 +0000 (+0200) Subject: wifi: mac80211: allocate backup ieee80211_nan_sched_cfg off stack X-Git-Tag: v7.2-rc4~17^2~16^2~44 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=44494b0d1d16e76ae805817579eacc801b10ed37;p=thirdparty%2Fkernel%2Flinux.git wifi: mac80211: allocate backup ieee80211_nan_sched_cfg off stack The ieee80211_nan_sched_cfg structure is too large to keep on the per thread stack: net/mac80211/nan.c:251:5: error: stack frame size (1560) exceeds limit (1536) in 'ieee80211_nan_set_local_sched' [-Werror,-Wframe-larger-than] 251 | int ieee80211_nan_set_local_sched(struct ieee80211_sub_if_data *sdata, Allocate this dynamically using kmalloc_obj() to reduce the stack usage of this function to a manageable 344 bytes for the same configuration. Fixes: 589c06e8fdee ("wifi: mac80211: add NAN local schedule support") Signed-off-by: Arnd Bergmann Link: https://patch.msgid.link/20260611130100.3387714-1-arnd@kernel.org Signed-off-by: Johannes Berg --- diff --git a/net/mac80211/nan.c b/net/mac80211/nan.c index 1800bb96dd29..19e08661be43 100644 --- a/net/mac80211/nan.c +++ b/net/mac80211/nan.c @@ -253,9 +253,12 @@ int ieee80211_nan_set_local_sched(struct ieee80211_sub_if_data *sdata, { struct ieee80211_nan_channel *sched_idx_to_chan[IEEE80211_NAN_MAX_CHANNELS] = {}; struct ieee80211_nan_sched_cfg *sched_cfg = &sdata->vif.cfg.nan_sched; - struct ieee80211_nan_sched_cfg backup_sched; + struct ieee80211_nan_sched_cfg *backup_sched __free(kfree) = kmalloc_obj(*backup_sched); int ret; + if (!backup_sched) + return -ENOMEM; + if (sched->n_channels > IEEE80211_NAN_MAX_CHANNELS) return -EOPNOTSUPP; @@ -275,13 +278,13 @@ int ieee80211_nan_set_local_sched(struct ieee80211_sub_if_data *sdata, bitmap_zero(sdata->u.nan.removed_channels, IEEE80211_NAN_MAX_CHANNELS); - memcpy(backup_sched.schedule, sched_cfg->schedule, - sizeof(backup_sched.schedule)); - memcpy(backup_sched.channels, sched_cfg->channels, - sizeof(backup_sched.channels)); - memcpy(backup_sched.avail_blob, sched_cfg->avail_blob, - sizeof(backup_sched.avail_blob)); - backup_sched.avail_blob_len = sched_cfg->avail_blob_len; + memcpy(backup_sched->schedule, sched_cfg->schedule, + sizeof(backup_sched->schedule)); + memcpy(backup_sched->channels, sched_cfg->channels, + sizeof(backup_sched->channels)); + memcpy(backup_sched->avail_blob, sched_cfg->avail_blob, + sizeof(backup_sched->avail_blob)); + backup_sched->avail_blob_len = sched_cfg->avail_blob_len; memcpy(sched_cfg->avail_blob, sched->nan_avail_blob, sched->nan_avail_blob_len); @@ -380,17 +383,17 @@ err: if (!chan_def->chan) continue; - if (!cfg80211_chandef_identical(&backup_sched.channels[i].chanreq.oper, + if (!cfg80211_chandef_identical(&backup_sched->channels[i].chanreq.oper, chan_def)) ieee80211_nan_remove_channel(sdata, &sched_cfg->channels[i]); } /* Re-add all backed up channels */ - for (int i = 0; i < ARRAY_SIZE(backup_sched.channels); i++) { + for (int i = 0; i < ARRAY_SIZE(backup_sched->channels); i++) { struct ieee80211_nan_channel *chan = &sched_cfg->channels[i]; - *chan = backup_sched.channels[i]; + *chan = backup_sched->channels[i]; /* * For deferred update, no channels were removed and the channel @@ -421,11 +424,11 @@ err: } } - memcpy(sched_cfg->schedule, backup_sched.schedule, - sizeof(backup_sched.schedule)); - memcpy(sched_cfg->avail_blob, backup_sched.avail_blob, - sizeof(backup_sched.avail_blob)); - sched_cfg->avail_blob_len = backup_sched.avail_blob_len; + memcpy(sched_cfg->schedule, backup_sched->schedule, + sizeof(backup_sched->schedule)); + memcpy(sched_cfg->avail_blob, backup_sched->avail_blob, + sizeof(backup_sched->avail_blob)); + sched_cfg->avail_blob_len = backup_sched->avail_blob_len; sched_cfg->deferred = false; bitmap_zero(sdata->u.nan.removed_channels, IEEE80211_NAN_MAX_CHANNELS);