Hi,
we have got an UBSAN report from opensuse's user who booten
UBSAN-enabled kernel by mistake:
UBSAN: Undefined behaviour in
drivers/net/wireless/intel/iwlwifi/mvm/utils.c:667:49
shift exponent 255 is too large for 64-bit type 'long unsigned int'
CPU: 2 PID: 1590 Comm: wpa_supplicant Not tainted 4.11.2-1-syzkaller #1
Hardware name: Dell Inc. Precision 5510/0N8J4R, BIOS 01.02.00 04/07/2016
Call Trace:
...
iwl_mvm_enable_txq+0xc6d/0x1080 [iwlmvm]
iwl_mvm_send_add_bcast_sta+0x275/0x850 [iwlmvm]
iwl_mvm_add_bcast_sta+0x11b/0x280 [iwlmvm]
iwl_mvm_mac_add_interface+0x51f/0x8b0 [iwlmvm]
drv_add_interface+0x1a7/0x8c0 [mac80211]
ieee80211_do_open+0xdff/0x2790 [mac80211]
ieee80211_start_p2p_device+0xac/0xf0 [mac80211]
nl80211_start_p2p_device+0x25d/0xab0 [cfg80211]
genl_family_rcv_msg+0x835/0xf10
genl_rcv_msg+0xd0/0x1c0
netlink_rcv_skb+0x226/0x310
genl_rcv+0x2d/0x40
netlink_unicast+0x631/0x9d0
netlink_sendmsg+0xa2e/0xf60
sock_sendmsg+0xf7/0x180
___sys_sendmsg+0x777/0xa60
__sys_sendmsg+0xd6/0x170
SyS_sendmsg+0x32/0x50
entry_SYSCALL_64_fastpath+0x23/0xc6
mac80211_queue is 255 which is IEEE80211_INVAL_HW_QUEUE, so it should
not be worked with at all.
The invalid queue is hopefully handled in ieee80211_check_queues after
drv_add_interface in ieee80211_do_open:
res = drv_add_interface(local, sdata);
if (res)
goto err_stop;
res = ieee80211_check_queues(sdata,
ieee80211_vif_type_p2p(&sdata->vif));
But the mvm driver still should not blindly shift 1 by 255 in
iwl_mvm_enable_txq. Should the check for the invalid queue be before
adding the interface in mac80211? Or should drivers check it in their
add_interface?
thanks,
--
js
suse labs
