Improper Locking

In the Linux kernel, the following vulnerability has been resolved: cfg80211: fix management registrations locking The management registrations locking was broken, the list was locked for each wdev, but cfg80211_mgmt_registrations_update() iterated it without holding all the correct spinlocks, causing list corruption. Rather than trying to fix it with fine-grained locking, just move the lock to the wiphy/rdev (still need the list on each wdev), we already need to hold the wdev lock to change it, so there's no contention on the lock in any case. This trivially fixes the bug since we hold one wdev's lock already, and now will hold the lock that protects all lists.Show less

In the Linux kernel, the following vulnerability has been resolved: isdn: mISDN: Fix sleeping function called from invalid context The driver can call card->isac.release() function from an atomic context. Fix this by calling this function after releasing the lock. The following log reveals it: [ 44.168226 ] BUG: sleeping function called from invalid context at kernel/workqueue.c:3018 [ 44.168941 ] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 5475, name: modprobe [ 44.169574 ] INFO: lockdep is turned off. [ 44.169899 ] irq event stamp: 0 [ 44.170160 ] hardirqs last enabled at (0): [<0000000000000000>] 0x0 [ 44.170627 ] hardirqs last disabled at (0): [<ffffffff814209ed>] copy_process+0x132d/0x3e00 [ 44.171240 ] softirqs last enabled at (0): [<ffffffff81420a1a>] copy_process+0x135a/0x3e00 [ 44.171852 ] softirqs last disabled at (0): [<0000000000000000>] 0x0 [ 44.172318 ] Preemption disabled at: [ 44.172320 ] [<ffffffffa009b0a9>] nj_release+0x69/0x500 [netjet] [ 44.174441 ] Call Trace: [ 44.174630 ] dump_stack_lvl+0xa8/0xd1 [ 44.174912 ] dump_stack+0x15/0x17 [ 44.175166 ] ___might_sleep+0x3a2/0x510 [ 44.175459 ] ? nj_release+0x69/0x500 [netjet] [ 44.175791 ] __might_sleep+0x82/0xe0 [ 44.176063 ] ? start_flush_work+0x20/0x7b0 [ 44.176375 ] start_flush_work+0x33/0x7b0 [ 44.176672 ] ? trace_irq_enable_rcuidle+0x85/0x170 [ 44.177034 ] ? kasan_quarantine_put+0xaa/0x1f0 [ 44.177372 ] ? kasan_quarantine_put+0xaa/0x1f0 [ 44.177711 ] __flush_work+0x11a/0x1a0 [ 44.177991 ] ? flush_work+0x20/0x20 [ 44.178257 ] ? lock_release+0x13c/0x8f0 [ 44.178550 ] ? __kasan_check_write+0x14/0x20 [ 44.178872 ] ? do_raw_spin_lock+0x148/0x360 [ 44.179187 ] ? read_lock_is_recursive+0x20/0x20 [ 44.179530 ] ? __kasan_check_read+0x11/0x20 [ 44.179846 ] ? do_raw_spin_unlock+0x55/0x900 [ 44.180168 ] ? ____kasan_slab_free+0x116/0x140 [ 44.180505 ] ? _raw_spin_unlock_irqrestore+0x41/0x60 [ 44.180878 ] ? skb_queue_purge+0x1a3/0x1c0 [ 44.181189 ] ? kfree+0x13e/0x290 [ 44.181438 ] flush_work+0x17/0x20 [ 44.181695 ] mISDN_freedchannel+0xe8/0x100 [ 44.182006 ] isac_release+0x210/0x260 [mISDNipac] [ 44.182366 ] nj_release+0xf6/0x500 [netjet] [ 44.182685 ] nj_remove+0x48/0x70 [netjet] [ 44.182989 ] pci_device_remove+0xa9/0x250Show less

In the Linux kernel, the following vulnerability has been resolved: iio: adis16475: fix deadlock on frequency set With commit 39c024b51b560 ("iio: adis16475: improve sync scale mode handling"), two deadlocks were introduced: 1) The call to 'adis_write_reg_16()' was not changed to it's unlocked version. 2) The lock was not being released on the success path of the function. This change fixes both these issues.Show less

In the Linux kernel, the following vulnerability has been resolved: ext4: fix racy may inline data check in dio write syzbot reports that the following warning from ext4_iomap_begin() triggers as of the commit referenced below: if (WARN_ON_ONCE(ext4_has_inline_data(inode))) return -ERANGE; This occurs during a dio write, which is never expected to encounter an inode with inline data. To enforce this behavior, ext4_dio_write_iter() checks the current inline state of the inode and clears the MAY_INLINE_DATA state flag to either fall back to buffered writes, or enforce that any other writers in progress on the inode are not allowed to create inline data. The problem is that the check for existing inline data and the state flag can span a lock cycle. For example, if the ilock is originally locked shared and subsequently upgraded to exclusive, another writer may have reacquired the lock and created inline data before the dio write task acquires the lock and proceeds. The commit referenced below loosens the lock requirements to allow some forms of unaligned dio writes to occur under shared lock, but AFAICT the inline data check was technically already racy for any dio write that would have involved a lock cycle. Regardless, lift clearing of the state bit to the same lock critical section that checks for preexisting inline data on the inode to close the race.Show less

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential deadlock when releasing mids All release_mid() callers seem to hold a reference of @mid so there is no need to call kref_put(&mid->refcount, __release_mid) under @server->mid_lock spinlock. If they don't, then an use-after-free bug would have occurred anyways. By getting rid of such spinlock also fixes a potential deadlock as shown below CPU 0 CPU 1 ------------------------------------------------------------------ cifs_demultiplex_thread() cifs_debug_data_proc_show() release_mid() spin_lock(&server->mid_lock); spin_lock(&cifs_tcp_ses_lock) spin_lock(&server->mid_lock) __release_mid() smb2_find_smb_tcon() spin_lock(&cifs_tcp_ses_lock) *deadlock*Show less

In the Linux kernel, the following vulnerability has been resolved: btrfs: lock the inode in shared mode before starting fiemap Currently fiemap does not take the inode's lock (VFS lock), it only locks a file range in the inode's io tree. This however can lead to a deadlock if we have a concurrent fsync on the file and fiemap code triggers a fault when accessing the user space buffer with fiemap_fill_next_extent(). The deadlock happens on the inode's i_mmap_lock semaphore, which is taken both by fsync and btrfs_page_mkwrite(). This deadlock was recently reported by syzbot and triggers a trace like the following: task:syz-executor361 state:D stack:20264 pid:5668 ppid:5119 flags:0x00004004 Call Trace: <TASK> context_switch kernel/sched/core.c:5293 [inline] __schedule+0x995/0xe20 kernel/sched/core.c:6606 schedule+0xcb/0x190 kernel/sched/core.c:6682 wait_on_state fs/btrfs/extent-io-tree.c:707 [inline] wait_extent_bit+0x577/0x6f0 fs/btrfs/extent-io-tree.c:751 lock_extent+0x1c2/0x280 fs/btrfs/extent-io-tree.c:1742 find_lock_delalloc_range+0x4e6/0x9c0 fs/btrfs/extent_io.c:488 writepage_delalloc+0x1ef/0x540 fs/btrfs/extent_io.c:1863 __extent_writepage+0x736/0x14e0 fs/btrfs/extent_io.c:2174 extent_write_cache_pages+0x983/0x1220 fs/btrfs/extent_io.c:3091 extent_writepages+0x219/0x540 fs/btrfs/extent_io.c:3211 do_writepages+0x3c3/0x680 mm/page-writeback.c:2581 filemap_fdatawrite_wbc+0x11e/0x170 mm/filemap.c:388 __filemap_fdatawrite_range mm/filemap.c:421 [inline] filemap_fdatawrite_range+0x175/0x200 mm/filemap.c:439 btrfs_fdatawrite_range fs/btrfs/file.c:3850 [inline] start_ordered_ops fs/btrfs/file.c:1737 [inline] btrfs_sync_file+0x4ff/0x1190 fs/btrfs/file.c:1839 generic_write_sync include/linux/fs.h:2885 [inline] btrfs_do_write_iter+0xcd3/0x1280 fs/btrfs/file.c:1684 call_write_iter include/linux/fs.h:2189 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7dc/0xc50 fs/read_write.c:584 ksys_write+0x177/0x2a0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7d4054e9b9 RSP: 002b:00007f7d404fa2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f7d405d87a0 RCX: 00007f7d4054e9b9 RDX: 0000000000000090 RSI: 0000000020000000 RDI: 0000000000000006 RBP: 00007f7d405a51d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 61635f65646f6e69 R13: 65646f7475616f6e R14: 7261637369646f6e R15: 00007f7d405d87a8 </TASK> INFO: task syz-executor361:5697 blocked for more than 145 seconds. Not tainted 6.2.0-rc3-syzkaller-00376-g7c6984405241 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor361 state:D stack:21216 pid:5697 ppid:5119 flags:0x00004004 Call Trace: <TASK> context_switch kernel/sched/core.c:5293 [inline] __schedule+0x995/0xe20 kernel/sched/core.c:6606 schedule+0xcb/0x190 kernel/sched/core.c:6682 rwsem_down_read_slowpath+0x5f9/0x930 kernel/locking/rwsem.c:1095 __down_read_common+0x54/0x2a0 kernel/locking/rwsem.c:1260 btrfs_page_mkwrite+0x417/0xc80 fs/btrfs/inode.c:8526 do_page_mkwrite+0x19e/0x5e0 mm/memory.c:2947 wp_page_shared+0x15e/0x380 mm/memory.c:3295 handle_pte_fault mm/memory.c:4949 [inline] __handle_mm_fault mm/memory.c:5073 [inline] handle_mm_fault+0x1b79/0x26b0 mm/memory.c:5219 do_user_addr_fault+0x69b/0xcb0 arch/x86/mm/fault.c:1428 handle_page_fault arch/x86/mm/fault.c:1519 [inline] exc_page_fault+0x7a/0x110 arch/x86/mm/fault.c:1575 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0010:copy_user_short_string+0xd/0x40 arch/x86/lib/copy_user_64.S:233 Code: 74 0a 89 (...) RSP: 0018:ffffc9000570f330 EFLAGS: 000502 ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: handle the case of pci_channel_io_frozen only in amdgpu_pci_resume In current code, when a PCI error state pci_channel_io_normal is detectd, it will report PCI_ERS_RESULT_CAN_RECOVER status to PCI driver, and PCI driver will continue the execution of PCI resume callback report_resume by pci_walk_bridge, and the callback will go into amdgpu_pci_resume finally, where write lock is releasd unconditionally without acquiring such lock first. In this case, a deadlock will happen when other threads start to acquire the read lock. To fix this, add a member in amdgpu_device strucutre to cache pci_channel_state, and only continue the execution in amdgpu_pci_resume when it's pci_channel_io_frozen.Show less

In the Linux kernel, the following vulnerability has been resolved: s390/qeth: fix deadlock during failing recovery Commit 0b9902c1fcc5 ("s390/qeth: fix deadlock during recovery") removed taking discipline_mutex inside qeth_do_reset(), fixing potential deadlocks. An error path was missed though, that still takes discipline_mutex and thus has the original deadlock potential. Intermittent deadlocks were seen when a qeth channel path is configured offline, causing a race between qeth_do_reset and ccwgroup_remove. Call qeth_set_offline() directly in the qeth_do_reset() error case and then a new variant of ccwgroup_set_offline(), without taking discipline_mutex.Show less

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix soft lockup during fsstress Below traces are observed during fsstress and system got hung. [ 130.698396] watchdog: BUG: soft lockup - CPU#6 stuck for 26s!Show less

In the Linux kernel, the following vulnerability has been resolved: powerpc/mm: Fix lockup on kernel exec fault The powerpc kernel is not prepared to handle exec faults from kernel. Especially, the function is_exec_fault() will return 'false' when an exec fault is taken by kernel, because the check is based on reading current->thread.regs->trap which contains the trap from user. For instance, when provoking a LKDTM EXEC_USERSPACE test, current->thread.regs->trap is set to SYSCALL trap (0xc00), and the fault taken by the kernel is not seen as an exec fault by set_access_flags_filter(). Commit d7df2443cd5f ("powerpc/mm: Fix spurious segfaults on radix with autonuma") made it clear and handled it properly. But later on commit d3ca587404b3 ("powerpc/mm: Fix reporting of kernel execute faults") removed that handling, introducing test based on error_code. And here is the problem, because on the 603 all upper bits of SRR1 get cleared when the TLB instruction miss handler bails out to ISI. Until commit cbd7e6ca0210 ("powerpc/fault: Avoid heavy search_exception_tables() verification"), an exec fault from kernel at a userspace address was indirectly caught by the lack of entry for that address in the exception tables. But after that commit the kernel mainly relies on KUAP or on core mm handling to catch wrong user accesses. Here the access is not wrong, so mm handles it. It is a minor fault because PAGE_EXEC is not set, set_access_flags_filter() should set PAGE_EXEC and voila. But as is_exec_fault() returns false as explained in the beginning, set_access_flags_filter() bails out without setting PAGE_EXEC flag, which leads to a forever minor exec fault. As the kernel is not prepared to handle such exec faults, the thing to do is to fire in bad_kernel_fault() for any exec fault taken by the kernel, as it was prior to commit d3ca587404b3.Show less

In the Linux kernel, the following vulnerability has been resolved: mwifiex: bring down link before deleting interface We can deadlock when rmmod'ing the driver or going through firmware reset, because the cfg80211_unregister_wdev() has to bring down the link for us, ... which then grab the same wiphy lock. nl80211_del_interface() already handles a very similar case, with a nice description: /* * We hold RTNL, so this is safe, without RTNL opencount cannot * reach 0, and thus the rdev cannot be deleted. * * We need to do it for the dev_close(), since that will call * the netdev notifiers, and we need to acquire the mutex there * but don't know if we get there from here or from some other * place (e.g. "ip link set ... down"). */ mutex_unlock(&rdev->wiphy.mtx); ... Do similarly for mwifiex teardown, by ensuring we bring the link down first. Sample deadlock trace: [ 247.103516] INFO: task rmmod:2119 blocked for more than 123 seconds. [ 247.110630] Not tainted 5.12.4 #5 [ 247.115796] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 247.124557] task:rmmod state:D stack: 0 pid: 2119 ppid: 2114 flags:0x00400208 [ 247.133905] Call trace: [ 247.136644] __switch_to+0x130/0x170 [ 247.140643] __schedule+0x714/0xa0c [ 247.144548] schedule_preempt_disabled+0x88/0xf4 [ 247.149714] __mutex_lock_common+0x43c/0x750 [ 247.154496] mutex_lock_nested+0x5c/0x68 [ 247.158884] cfg80211_netdev_notifier_call+0x280/0x4e0 [cfg80211] [ 247.165769] raw_notifier_call_chain+0x4c/0x78 [ 247.170742] call_netdevice_notifiers_info+0x68/0xa4 [ 247.176305] __dev_close_many+0x7c/0x138 [ 247.180693] dev_close_many+0x7c/0x10c [ 247.184893] unregister_netdevice_many+0xfc/0x654 [ 247.190158] unregister_netdevice_queue+0xb4/0xe0 [ 247.195424] _cfg80211_unregister_wdev+0xa4/0x204 [cfg80211] [ 247.201816] cfg80211_unregister_wdev+0x20/0x2c [cfg80211] [ 247.208016] mwifiex_del_virtual_intf+0xc8/0x188 [mwifiex] [ 247.214174] mwifiex_uninit_sw+0x158/0x1b0 [mwifiex] [ 247.219747] mwifiex_remove_card+0x38/0xa0 [mwifiex] [ 247.225316] mwifiex_pcie_remove+0xd0/0xe0 [mwifiex_pcie] [ 247.231451] pci_device_remove+0x50/0xe0 [ 247.235849] device_release_driver_internal+0x110/0x1b0 [ 247.241701] driver_detach+0x5c/0x9c [ 247.245704] bus_remove_driver+0x84/0xb8 [ 247.250095] driver_unregister+0x3c/0x60 [ 247.254486] pci_unregister_driver+0x2c/0x90 [ 247.259267] cleanup_module+0x18/0xcdc [mwifiex_pcie]Show less

In the Linux kernel, the following vulnerability has been resolved: powerpc/bpf: Fix detecting BPF atomic instructions Commit 91c960b0056672 ("bpf: Rename BPF_XADD and prepare to encode other atomics in .imm") converted BPF_XADD to BPF_ATOMIC and added a way to distinguish instructions based on the immediate field. Existing JIT implementations were updated to check for the immediate field and to reject programs utilizing anything more than BPF_ADD (such as BPF_FETCH) in the immediate field. However, the check added to powerpc64 JIT did not look at the correct BPF instruction. Due to this, such programs would be accepted and incorrectly JIT'ed resulting in soft lockups, as seen with the atomic bounds test. Fix this by looking at the correct immediate value.Show less

In the Linux kernel, the following vulnerability has been resolved: usb: cdnsp: Fix deadlock issue in cdnsp_thread_irq_handler Patch fixes the following critical issue caused by deadlock which has been detected during testing NCM class: smp: csd: Detected non-responsive CSD lock (#1) on CPU#0 smp: csd: CSD lock (#1) unresponsive. .... RIP: 0010:native_queued_spin_lock_slowpath+0x61/0x1d0 RSP: 0018:ffffbc494011cde0 EFLAGS: 00000002 RAX: 0000000000000101 RBX: ffff9ee8116b4a68 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9ee8116b4658 RBP: ffffbc494011cde0 R08: 0000000000000001 R09: 0000000000000000 R10: ffff9ee8116b4670 R11: 0000000000000000 R12: ffff9ee8116b4658 R13: ffff9ee8116b4670 R14: 0000000000000246 R15: ffff9ee8116b4658 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7bcc41a830 CR3: 000000007a612003 CR4: 00000000001706e0 Call Trace: <IRQ> do_raw_spin_lock+0xc0/0xd0 _raw_spin_lock_irqsave+0x95/0xa0 cdnsp_gadget_ep_queue.cold+0x88/0x107 [cdnsp_udc_pci] usb_ep_queue+0x35/0x110 eth_start_xmit+0x220/0x3d0 [u_ether] ncm_tx_timeout+0x34/0x40 [usb_f_ncm] ? ncm_free_inst+0x50/0x50 [usb_f_ncm] __hrtimer_run_queues+0xac/0x440 hrtimer_run_softirq+0x8c/0xb0 __do_softirq+0xcf/0x428 asm_call_irq_on_stack+0x12/0x20 </IRQ> do_softirq_own_stack+0x61/0x70 irq_exit_rcu+0xc1/0xd0 sysvec_apic_timer_interrupt+0x52/0xb0 asm_sysvec_apic_timer_interrupt+0x12/0x20 RIP: 0010:do_raw_spin_trylock+0x18/0x40 RSP: 0018:ffffbc494138bda8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff9ee8116b4658 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff9ee8116b4658 RBP: ffffbc494138bda8 R08: 0000000000000001 R09: 0000000000000000 R10: ffff9ee8116b4670 R11: 0000000000000000 R12: ffff9ee8116b4658 R13: ffff9ee8116b4670 R14: ffff9ee7b5c73d80 R15: ffff9ee8116b4000 _raw_spin_lock+0x3d/0x70 ? cdnsp_thread_irq_handler.cold+0x32/0x112c [cdnsp_udc_pci] cdnsp_thread_irq_handler.cold+0x32/0x112c [cdnsp_udc_pci] ? cdnsp_remove_request+0x1f0/0x1f0 [cdnsp_udc_pci] ? cdnsp_thread_irq_handler+0x5/0xa0 [cdnsp_udc_pci] ? irq_thread+0xa0/0x1c0 irq_thread_fn+0x28/0x60 irq_thread+0x105/0x1c0 ? __kthread_parkme+0x42/0x90 ? irq_forced_thread_fn+0x90/0x90 ? wake_threads_waitq+0x30/0x30 ? irq_thread_check_affinity+0xe0/0xe0 kthread+0x12a/0x160 ? kthread_park+0x90/0x90 ret_from_fork+0x22/0x30 The root cause of issue is spin_lock/spin_unlock instruction instead spin_lock_irqsave/spin_lock_irqrestore in cdnsp_thread_irq_handler function.Show less

In the Linux kernel, the following vulnerability has been resolved: mptcp: fix soft lookup in subflow_error_report() Maxim reported a soft lookup in subflow_error_report(): watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:0] RIP: 0010:native_queued_spin_lock_slowpath RSP: 0018:ffffa859c0003bc0 EFLAGS: 00000202 RAX: 0000000000000101 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff9195c2772d88 RSI: 0000000000000000 RDI: ffff9195c2772d88 RBP: ffff9195c2772d00 R08: 00000000000067b0 R09: c6e31da9eb1e44f4 R10: ffff9195ef379700 R11: ffff9195edb50710 R12: ffff9195c2772d88 R13: ffff9195f500e3d0 R14: ffff9195ef379700 R15: ffff9195ef379700 FS: 0000000000000000(0000) GS:ffff91961f400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c000407000 CR3: 0000000002988000 CR4: 00000000000006f0 Call Trace: <IRQ> _raw_spin_lock_bh subflow_error_report mptcp_subflow_data_available __mptcp_move_skbs_from_subflow mptcp_data_ready tcp_data_queue tcp_rcv_established tcp_v4_do_rcv tcp_v4_rcv ip_protocol_deliver_rcu ip_local_deliver_finish __netif_receive_skb_one_core netif_receive_skb rtl8139_poll 8139too __napi_poll net_rx_action __do_softirq __irq_exit_rcu common_interrupt </IRQ> The calling function - mptcp_subflow_data_available() - can be invoked from different contexts: - plain ssk socket lock - ssk socket lock + mptcp_data_lock - ssk socket lock + mptcp_data_lock + msk socket lock. Since subflow_error_report() tries to acquire the mptcp_data_lock, the latter two call chains will cause soft lookup. This change addresses the issue moving the error reporting call to outer functions, where the held locks list is known and the we can acquire only the needed one.Show less

In the Linux kernel, the following vulnerability has been resolved: mac80211: fix deadlock in AP/VLAN handling Syzbot reports that when you have AP_VLAN interfaces that are up and close the AP interface they belong to, we get a deadlock. No surprise - since we dev_close() them with the wiphy mutex held, which goes back into the netdev notifier in cfg80211 and tries to acquire the wiphy mutex there. To fix this, we need to do two things: 1) prevent changing iftype while AP_VLANs are up, we can't easily fix this case since cfg80211 already calls us with the wiphy mutex held, but change_interface() is relatively rare in drivers anyway, so changing iftype isn't used much (and userspace has to fall back to down/change/up anyway) 2) pull the dev_close() loop over VLANs out of the wiphy mutex section in the normal stop caseShow less

In the Linux kernel, the following vulnerability has been resolved: ice: fix LAG and VF lock dependency in ice_reset_vf() 9f74a3dfcf83 ("ice: Fix VF Reset paths when interface in a failed over aggregate"), the ice driver has acquired the LAG mutex in ice_reset_vf(). The commit placed this lock acquisition just prior to the acquisition of the VF configuration lock. If ice_reset_vf() acquires the configuration lock via the ICE_VF_RESET_LOCK flag, this could deadlock with ice_vc_cfg_qs_msg() because it always acquires the locks in the order of the VF configuration lock and then the LAG mutex. Lockdep reports this violation almost immediately on creating and then removing 2 VF: ====================================================== WARNING: possible circular locking dependency detected 6.8.0-rc6 #54 Tainted: G W O ------------------------------------------------------ kworker/60:3/6771 is trying to acquire lock: ff40d43e099380a0 (&vf->cfg_lock){+.+.}-{3:3}, at: ice_reset_vf+0x22f/0x4d0 [ice] but task is already holding lock: ff40d43ea1961210 (&pf->lag_mutex){+.+.}-{3:3}, at: ice_reset_vf+0xb7/0x4d0 [ice] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&pf->lag_mutex){+.+.}-{3:3}: __lock_acquire+0x4f8/0xb40 lock_acquire+0xd4/0x2d0 __mutex_lock+0x9b/0xbf0 ice_vc_cfg_qs_msg+0x45/0x690 [ice] ice_vc_process_vf_msg+0x4f5/0x870 [ice] __ice_clean_ctrlq+0x2b5/0x600 [ice] ice_service_task+0x2c9/0x480 [ice] process_one_work+0x1e9/0x4d0 worker_thread+0x1e1/0x3d0 kthread+0x104/0x140 ret_from_fork+0x31/0x50 ret_from_fork_asm+0x1b/0x30 -> #0 (&vf->cfg_lock){+.+.}-{3:3}: check_prev_add+0xe2/0xc50 validate_chain+0x558/0x800 __lock_acquire+0x4f8/0xb40 lock_acquire+0xd4/0x2d0 __mutex_lock+0x9b/0xbf0 ice_reset_vf+0x22f/0x4d0 [ice] ice_process_vflr_event+0x98/0xd0 [ice] ice_service_task+0x1cc/0x480 [ice] process_one_work+0x1e9/0x4d0 worker_thread+0x1e1/0x3d0 kthread+0x104/0x140 ret_from_fork+0x31/0x50 ret_from_fork_asm+0x1b/0x30 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pf->lag_mutex); lock(&vf->cfg_lock); lock(&pf->lag_mutex); lock(&vf->cfg_lock); *** DEADLOCK *** 4 locks held by kworker/60:3/6771: #0: ff40d43e05428b38 ((wq_completion)ice){+.+.}-{0:0}, at: process_one_work+0x176/0x4d0 #1: ff50d06e05197e58 ((work_completion)(&pf->serv_task)){+.+.}-{0:0}, at: process_one_work+0x176/0x4d0 #2: ff40d43ea1960e50 (&pf->vfs.table_lock){+.+.}-{3:3}, at: ice_process_vflr_event+0x48/0xd0 [ice] #3: ff40d43ea1961210 (&pf->lag_mutex){+.+.}-{3:3}, at: ice_reset_vf+0xb7/0x4d0 [ice] stack backtrace: CPU: 60 PID: 6771 Comm: kworker/60:3 Tainted: G W O 6.8.0-rc6 #54 Hardware name: Workqueue: ice ice_service_task [ice] Call Trace: <TASK> dump_stack_lvl+0x4a/0x80 check_noncircular+0x12d/0x150 check_prev_add+0xe2/0xc50 ? save_trace+0x59/0x230 ? add_chain_cache+0x109/0x450 validate_chain+0x558/0x800 __lock_acquire+0x4f8/0xb40 ? lockdep_hardirqs_on+0x7d/0x100 lock_acquire+0xd4/0x2d0 ? ice_reset_vf+0x22f/0x4d0 [ice] ? lock_is_held_type+0xc7/0x120 __mutex_lock+0x9b/0xbf0 ? ice_reset_vf+0x22f/0x4d0 [ice] ? ice_reset_vf+0x22f/0x4d0 [ice] ? rcu_is_watching+0x11/0x50 ? ice_reset_vf+0x22f/0x4d0 [ice] ice_reset_vf+0x22f/0x4d0 [ice] ? process_one_work+0x176/0x4d0 ice_process_vflr_event+0x98/0xd0 [ice] ice_service_task+0x1cc/0x480 [ice] process_one_work+0x1e9/0x4d0 worker_thread+0x1e1/0x3d0 ? __pfx_worker_thread+0x10/0x10 kthread+0x104/0x140 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK> To avoid deadlock, we must acquire the LAG ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: smb3: missing lock when picking channel Coverity spotted a place where we should have been holding the channel lock when accessing the ses channel index. Addresses-Coverity: 1582039 ("Data race condition (MISSING_LOCK)")Show less

In the Linux kernel, the following vulnerability has been resolved: smb3: fix lock ordering potential deadlock in cifs_sync_mid_result Coverity spotted that the cifs_sync_mid_result function could deadlock "Thread deadlock (ORDER_REVERSAL) lock_order: Calling spin_lock acquires lock TCP_Server_Info.srv_lock while holding lock TCP_Server_Info.mid_lock" Addresses-Coverity: 1590401 ("Thread deadlock (ORDER_REVERSAL)")Show less

In the Linux kernel, the following vulnerability has been resolved: HID: i2c-hid: remove I2C_HID_READ_PENDING flag to prevent lock-up The flag I2C_HID_READ_PENDING is used to serialize I2C operations. However, this is not necessary, because I2C core already has its own locking for that. More importantly, this flag can cause a lock-up: if the flag is set in i2c_hid_xfer() and an interrupt happens, the interrupt handler (i2c_hid_irq) will check this flag and return immediately without doing anything, then the interrupt handler will be invoked again in an infinite loop. Since interrupt handler is an RT task, it takes over the CPU and the flag-clearing task never gets scheduled, thus we have a lock-up. Delete this unnecessary flag.Show less

In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: Convert spinlock to mutex to lock evl workqueue drain_workqueue() cannot be called safely in a spinlocked context due to possible task rescheduling. In the multi-task scenario, calling queue_work() while drain_workqueue() will lead to a Call Trace as pushing a work on a draining workqueue is not permitted in spinlocked context. Call Trace: <TASK> ? __warn+0x7d/0x140 ? __queue_work+0x2b2/0x440 ? report_bug+0x1f8/0x200 ? handle_bug+0x3c/0x70 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? __queue_work+0x2b2/0x440 queue_work_on+0x28/0x30 idxd_misc_thread+0x303/0x5a0 [idxd] ? __schedule+0x369/0xb40 ? __pfx_irq_thread_fn+0x10/0x10 ? irq_thread+0xbc/0x1b0 irq_thread_fn+0x21/0x70 irq_thread+0x102/0x1b0 ? preempt_count_add+0x74/0xa0 ? __pfx_irq_thread_dtor+0x10/0x10 ? __pfx_irq_thread+0x10/0x10 kthread+0x103/0x140 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK> The current implementation uses a spinlock to protect event log workqueue and will lead to the Call Trace due to potential task rescheduling. To address the locking issue, convert the spinlock to mutex, allowing the drain_workqueue() to be called in a safe mutex-locked context. This change ensures proper synchronization when accessing the event log workqueue, preventing potential Call Trace and improving the overall robustness of the code.Show less