CVE-2024-42114: Improper Locking

In the Linux kernel, the following vulnerability has been resolved:

wifi: cfg80211: restrict NL80211_ATTR_TXQ_QUANTUM values

syzbot is able to trigger softlockups, setting NL80211_ATTR_TXQ_QUANTUM to 2^31.

We had a similar issue in sch_fq, fixed with commit d9e15a273306 ("pkt_sched: fq: do not accept silly TCA_FQ_QUANTUM")

watchdog: BUG: soft lockup - CPU#1 stuck for 26s! [kworker/1:0:24] Modules linked in: irq event stamp: 131135 hardirqs last enabled at (131134): [<ffff80008ae8778c>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:85 [inline] hardirqs last enabled at (131134): [<ffff80008ae8778c>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:95 hardirqs last disabled at (131135): [<ffff80008ae85378>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline] hardirqs last disabled at (131135): [<ffff80008ae85378>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551 softirqs last enabled at (125892): [<ffff80008907e82c>] neigh_hh_init net/core/neighbour.c:1538 [inline] softirqs last enabled at (125892): [<ffff80008907e82c>] neigh_resolve_output+0x268/0x658 net/core/neighbour.c:1553 softirqs last disabled at (125896): [<ffff80008904166c>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19 CPU: 1 PID: 24 Comm: kworker/1:0 Not tainted 6.9.0-rc7-syzkaller-gfda5695d692c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: mld mld_ifc_work pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __list_del include/linux/list.h:195 [inline] pc : __list_del_entry include/linux/list.h:218 [inline] pc : list_move_tail include/linux/list.h:310 [inline] pc : fq_tin_dequeue include/net/fq_impl.h:112 [inline] pc : ieee80211_tx_dequeue+0x6b8/0x3b4c net/mac80211/tx.c:3854 lr : __list_del_entry include/linux/list.h:218 [inline] lr : list_move_tail include/linux/list.h:310 [inline] lr : fq_tin_dequeue include/net/fq_impl.h:112 [inline] lr : ieee80211_tx_dequeue+0x67c/0x3b4c net/mac80211/tx.c:3854 sp : ffff800093d36700 x29: ffff800093d36a60 x28: ffff800093d36960 x27: dfff800000000000 x26: ffff0000d800ad50 x25: ffff0000d800abe0 x24: ffff0000d800abf0 x23: ffff0000e0032468 x22: ffff0000e00324d4 x21: ffff0000d800abf0 x20: ffff0000d800abf8 x19: ffff0000d800abf0 x18: ffff800093d363c0 x17: 000000000000d476 x16: ffff8000805519dc x15: ffff7000127a6cc8 x14: 1ffff000127a6cc8 x13: 0000000000000004 x12: ffffffffffffffff x11: ffff7000127a6cc8 x10: 0000000000ff0100 x9 : 0000000000000000 x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000 x5 : ffff80009287aa08 x4 : 0000000000000008 x3 : ffff80008034c7fc x2 : ffff0000e0032468 x1 : 00000000da0e46b8 x0 : ffff0000e0032470 Call trace: __list_del include/linux/list.h:195 [inline] __list_del_entry include/linux/list.h:218 [inline] list_move_tail include/linux/list.h:310 [inline] fq_tin_dequeue include/net/fq_impl.h:112 [inline] ieee80211_tx_dequeue+0x6b8/0x3b4c net/mac80211/tx.c:3854 wake_tx_push_queue net/mac80211/util.c:294 [inline] ieee80211_handle_wake_tx_queue+0x118/0x274 net/mac80211/util.c:315 drv_wake_tx_queue net/mac80211/driver-ops.h:1350 [inline] schedule_and_wake_txq net/mac80211/driver-ops.h:1357 [inline] ieee80211_queue_skb+0x18e8/0x2244 net/mac80211/tx.c:1664 ieee80211_tx+0x260/0x400 net/mac80211/tx.c:1966 ieee80211_xmit+0x278/0x354 net/mac80211/tx.c:2062 __ieee80211_subif_start_xmit+0xab8/0x122c net/mac80211/tx.c:4338 ieee80211_subif_start_xmit+0xe0/0x438 net/mac80211/tx.c:4532 __netdev_start_xmit include/linux/netdevice.h:4903 [inline] netdev_start_xmit include/linux/netdevice.h:4917 [inline] xmit_one net/core/dev.c:3531 [inline] dev_hard_start_xmit+0x27c/0x938 net/core/dev.c:3547 __dev_queue_xmit+0x1678/0x33fc net/core/dev.c:4341 dev_queue_xmit include/linux/netdevice.h:3091 [inline] neigh_resolve_output+0x558/0x658 net/core/neighbour.c:1563 neigh_output include/net/neighbour.h:542 [inline] ip6_fini ---truncated---