brcmu_pkt_buf_free_skb emits WARNING when attempting to free a sk_buff which is part of any queue. After USB disconnect this may have happened when brcmf_fws_hanger_cleanup() is called as per-interface psq was never cleaned when removing the interface. Change brcmf_fws_macdesc_cleanup() in a way that it removes the corresponding packets from hanger table (to avoid double-free when brcmf_fws_hanger_cleanup() is called) and add a call to clean-up the interface specific packet queue. Below is a WARNING during USB disconnect with Raspberry Pi WiFi dongle running in AP mode. This was reproducible when the interface was transmitting during the disconnect and is fixed with this commit. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1171 at drivers/net/wireless/broadcom/brcm80211/brcmutil/utils.c:49 brcmu_pkt_buf_free_skb+0x3c/0x40 Modules linked in: nf_log_ipv4 nf_log_common xt_LOG xt_limit iptable_mangle xt_connmark xt_tcpudp xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter ip_tables x_tables usb_f_mass_storage usb_f_rndis u_ether cdc_acm smsc95xx usbnet ci_hdrc_imx ci_hdrc ulpi usbmisc_imx 8250_exar 8250_pci 8250 8250_base libcomposite configfs udc_core CPU: 0 PID: 1171 Comm: kworker/0:0 Not tainted 4.19.23-00075-gde33ed8 #99 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Workqueue: usb_hub_wq hub_event [<8010ff84>] (unwind_backtrace) from [<8010bb64>] (show_stack+0x10/0x14) [<8010bb64>] (show_stack) from [<80840278>] (dump_stack+0x88/0x9c) [<80840278>] (dump_stack) from [<8011f5ec>] (__warn+0xfc/0x114) [<8011f5ec>] (__warn) from [<8011f71c>] (warn_slowpath_null+0x40/0x48) [<8011f71c>] (warn_slowpath_null) from [<805a476c>] (brcmu_pkt_buf_free_skb+0x3c/0x40) [<805a476c>] (brcmu_pkt_buf_free_skb) from [<805bb6c4>] (brcmf_fws_cleanup+0x1e4/0x22c) [<805bb6c4>] (brcmf_fws_cleanup) from [<805bc854>] (brcmf_fws_del_interface+0x58/0x68) [<805bc854>] (brcmf_fws_del_interface) from [<805b66ac>] (brcmf_remove_interface+0x40/0x150) [<805b66ac>] (brcmf_remove_interface) from [<805b6870>] (brcmf_detach+0x6c/0xb0) [<805b6870>] (brcmf_detach) from [<805bdbb8>] (brcmf_usb_disconnect+0x30/0x4c) [<805bdbb8>] (brcmf_usb_disconnect) from [<805e5d64>] (usb_unbind_interface+0x5c/0x1e0) [<805e5d64>] (usb_unbind_interface) from [<804aab10>] (device_release_driver_internal+0x154/0x1ec) [<804aab10>] (device_release_driver_internal) from [<804a97f4>] (bus_remove_device+0xcc/0xf8) [<804a97f4>] (bus_remove_device) from [<804a6fc0>] (device_del+0x118/0x308) [<804a6fc0>] (device_del) from [<805e488c>] (usb_disable_device+0xa0/0x1c8) [<805e488c>] (usb_disable_device) from [<805dcf98>] (usb_disconnect+0x70/0x1d8) [<805dcf98>] (usb_disconnect) from [<805ddd84>] (hub_event+0x464/0xf50) [<805ddd84>] (hub_event) from [<80135a70>] (process_one_work+0x138/0x3f8) [<80135a70>] (process_one_work) from [<80135d5c>] (worker_thread+0x2c/0x554) [<80135d5c>] (worker_thread) from [<8013b1a0>] (kthread+0x124/0x154) [<8013b1a0>] (kthread) from [<801010e8>] (ret_from_fork+0x14/0x2c) Exception stack(0xecf8dfb0 to 0xecf8dff8) dfa0: 00000000 00000000 00000000 00000000 dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 ---[ end trace 38d234018e9e2a90 ]--- ------------[ cut here ]------------ Signed-off-by: Piotr Figiel <p.figiel@xxxxxxxxxxxxxxxxxxxxxx> --- .../broadcom/brcm80211/brcmfmac/fwsignal.c | 42 ++++++++++++---------- 1 file changed, 24 insertions(+), 18 deletions(-) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c index abeb305..d48b8b2 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c @@ -580,24 +580,6 @@ static bool brcmf_fws_ifidx_match(struct sk_buff *skb, void *arg) return ifidx == *(int *)arg; } -static void brcmf_fws_psq_flush(struct brcmf_fws_info *fws, struct pktq *q, - int ifidx) -{ - bool (*matchfn)(struct sk_buff *, void *) = NULL; - struct sk_buff *skb; - int prec; - - if (ifidx != -1) - matchfn = brcmf_fws_ifidx_match; - for (prec = 0; prec < q->num_prec; prec++) { - skb = brcmu_pktq_pdeq_match(q, prec, matchfn, &ifidx); - while (skb) { - brcmu_pkt_buf_free_skb(skb); - skb = brcmu_pktq_pdeq_match(q, prec, matchfn, &ifidx); - } - } -} - static void brcmf_fws_hanger_init(struct brcmf_fws_hanger *hanger) { int i; @@ -669,6 +651,28 @@ static inline int brcmf_fws_hanger_poppkt(struct brcmf_fws_hanger *h, return 0; } +static void brcmf_fws_psq_flush(struct brcmf_fws_info *fws, struct pktq *q, + int ifidx) +{ + bool (*matchfn)(struct sk_buff *, void *) = NULL; + struct sk_buff *skb; + int prec; + u32 hslot; + + if (ifidx != -1) + matchfn = brcmf_fws_ifidx_match; + for (prec = 0; prec < q->num_prec; prec++) { + skb = brcmu_pktq_pdeq_match(q, prec, matchfn, &ifidx); + while (skb) { + hslot = brcmf_skb_htod_tag_get_field(skb, HSLOT); + brcmf_fws_hanger_poppkt(&fws->hanger, hslot, &skb, + true); + brcmu_pkt_buf_free_skb(skb); + skb = brcmu_pktq_pdeq_match(q, prec, matchfn, &ifidx); + } + } +} + static int brcmf_fws_hanger_mark_suppressed(struct brcmf_fws_hanger *h, u32 slot_id) { @@ -2200,6 +2204,8 @@ void brcmf_fws_del_interface(struct brcmf_if *ifp) brcmf_fws_lock(fws); ifp->fws_desc = NULL; brcmf_dbg(TRACE, "deleting %s\n", entry->name); + brcmf_fws_macdesc_cleanup(fws, &fws->desc.iface[ifp->ifidx], + ifp->ifidx); brcmf_fws_macdesc_deinit(entry); brcmf_fws_cleanup(fws, ifp->ifidx); brcmf_fws_unlock(fws); -- 2.7.4