In the Linux kernel, the following vulnerability has been resolved: audit: improve robustness of the audit queue handling If the audit daemon were ever to get stuck in a stopped state the kernel's kauditd_thread() could get blocked attempting to send audit records to the userspace audit daemon. With the kernel thread blocked it is possible that the audit queue could grow unbounded as certain audit record generating events must be exempt from the queue limits else the system enter a deadlock state. This patch resolves this problem by lowering the kernel thread's socket sending timeout from MAX_SCHEDULE_TIMEOUT to HZ/10 and tweaks the kauditd_send_queue() function to better manage the various audit queues when connection problems occur between the kernel and the audit daemon. With this patch, the backlog may temporarily grow beyond the defined limits when the audit daemon is stopped and the system is under heavy audit pressure, but kauditd_thread() will continue to make progress and drain the queues as it would for other connection problems. For example, with the audit daemon put into a stopped state and the system configured to audit every syscall it was still possible to shutdown the system without a kernel panic, deadlock, etc.; granted, the system was slow to shutdown but that is to be expected given the extreme pressure of recording every syscall. The timeout value of HZ/10 was chosen primarily through experimentation and this developer's "gut feeling". There is likely no one perfect value, but as this scenario is limited in scope (root privileges would be needed to send SIGSTOP to the audit daemon), it is likely not worth exposing this as a tunable at present. This can always be done at a later date if it proves necessary.

A deadlock flaw was found in the Linux kernel’s BPF subsystem. This flaw allows a local user to potentially crash the system.

In the Linux kernel, the following vulnerability has been resolved: ext4: fix i_data_sem unlock order in ext4_ind_migrate() Fuzzing reports a possible deadlock in jbd2_log_wait_commit. This issue is triggered when an EXT4_IOC_MIGRATE ioctl is set to require synchronous updates because the file descriptor is opened with O_SYNC. This can lead to the jbd2_journal_stop() function calling jbd2_might_wait_for_commit(), potentially causing a deadlock if the EXT4_IOC_MIGRATE call races with a write(2) system call. This problem only arises when CONFIG_PROVE_LOCKING is enabled. In this case, the jbd2_might_wait_for_commit macro locks jbd2_handle in the jbd2_journal_stop function while i_data_sem is locked. This triggers lockdep because the jbd2_journal_start function might also lock the same jbd2_handle simultaneously. Found by Linux Verification Center (linuxtesting.org) with syzkaller. Rule: add

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---