In the Linux kernel, the following vulnerability has been resolved: padata: Fix possible divide-by-0 panic in padata_mt_helper() We are hit with a not easily reproducible divide-by-0 panic in padata.c at bootup time. [ 10.017908] Oops: divide error: 0000 1 PREEMPT SMP NOPTI [ 10.017908] CPU: 26 PID: 2627 Comm: kworker/u1666:1 Not tainted 6.10.0-15.el10.x86_64 #1 [ 10.017908] Hardware name: Lenovo ThinkSystem SR950 [7X12CTO1WW]/[7X12CTO1WW], BIOS [PSE140J-2.30] 07/20/2021 [ 10.017908] Workqueue: events_unbound padata_mt_helper [ 10.017908] RIP: 0010:padata_mt_helper+0x39/0xb0 : [ 10.017963] Call Trace: [ 10.017968] <TASK> [ 10.018004] ? padata_mt_helper+0x39/0xb0 [ 10.018084] process_one_work+0x174/0x330 [ 10.018093] worker_thread+0x266/0x3a0 [ 10.018111] kthread+0xcf/0x100 [ 10.018124] ret_from_fork+0x31/0x50 [ 10.018138] ret_from_fork_asm+0x1a/0x30 [ 10.018147] </TASK> Looking at the padata_mt_helper() function, the only way a divide-by-0 panic can happen is when ps->chunk_size is 0. The way that chunk_size is initialized in padata_do_multithreaded(), chunk_size can be 0 when the min_chunk in the passed-in padata_mt_job structure is 0. Fix this divide-by-0 panic by making sure that chunk_size will be at least 1 no matter what the input parameters are.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null check in resource_log_pipe_topology_update [WHY] When switching from "Extend" to "Second Display Only" we sometimes call resource_get_otg_master_for_stream on a stream for the eDP, which is disconnected. This leads to a null pointer dereference. [HOW] Added a null check in dc_resource.c/resource_log_pipe_topology_update.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: Add error handling to pair_device() hci_conn_params_add() never checks for a NULL value and could lead to a NULL pointer dereference causing a crash. Fixed by adding error handling in the function.

In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: make apf token non-zero to fix bug In current async pagefault logic, when a page is ready, KVM relies on kvm_arch_can_dequeue_async_page_present() to determine whether to deliver a READY event to the Guest. This function test token value of struct kvm_vcpu_pv_apf_data, which must be reset to zero by Guest kernel when a READY event is finished by Guest. If value is zero meaning that a READY event is done, so the KVM can deliver another. But the kvm_arch_setup_async_pf() may produce a valid token with zero value, which is confused with previous mention and may lead the loss of this READY event. This bug may cause task blocked forever in Guest: INFO: task stress:7532 blocked for more than 1254 seconds. Not tainted 5.10.0 #16 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:stress state:D stack: 0 pid: 7532 ppid: 1409 flags:0x00000080 Call Trace: __schedule+0x1e7/0x650 schedule+0x46/0xb0 kvm_async_pf_task_wait_schedule+0xad/0xe0 ? exit_to_user_mode_prepare+0x60/0x70 __kvm_handle_async_pf+0x4f/0xb0 ? asm_exc_page_fault+0x8/0x30 exc_page_fault+0x6f/0x110 ? asm_exc_page_fault+0x8/0x30 asm_exc_page_fault+0x1e/0x30 RIP: 0033:0x402d00 RSP: 002b:00007ffd31912500 EFLAGS: 00010206 RAX: 0000000000071000 RBX: ffffffffffffffff RCX: 00000000021a32b0 RDX: 000000000007d011 RSI: 000000000007d000 RDI: 00000000021262b0 RBP: 00000000021262b0 R08: 0000000000000003 R09: 0000000000000086 R10: 00000000000000eb R11: 00007fefbdf2baa0 R12: 0000000000000000 R13: 0000000000000002 R14: 000000000007d000 R15: 0000000000001000

In the Linux kernel, the following vulnerability has been resolved: hwmon: Handle failure to register sensor with thermal zone correctly If an attempt is made to a sensor with a thermal zone and it fails, the call to devm_thermal_zone_of_sensor_register() may return -ENODEV. This may result in crashes similar to the following. Unable to handle kernel NULL pointer dereference at virtual address 00000000000003cd ... Internal error: Oops: 96000021 [#1] PREEMPT SMP ... pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : mutex_lock+0x18/0x60 lr : thermal_zone_device_update+0x40/0x2e0 sp : ffff800014c4fc60 x29: ffff800014c4fc60 x28: ffff365ee3f6e000 x27: ffffdde218426790 x26: ffff365ee3f6e000 x25: 0000000000000000 x24: ffff365ee3f6e000 x23: ffffdde218426870 x22: ffff365ee3f6e000 x21: 00000000000003cd x20: ffff365ee8bf3308 x19: ffffffffffffffed x18: 0000000000000000 x17: ffffdde21842689c x16: ffffdde1cb7a0b7c x15: 0000000000000040 x14: ffffdde21a4889a0 x13: 0000000000000228 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 x8 : 0000000001120000 x7 : 0000000000000001 x6 : 0000000000000000 x5 : 0068000878e20f07 x4 : 0000000000000000 x3 : 00000000000003cd x2 : ffff365ee3f6e000 x1 : 0000000000000000 x0 : 00000000000003cd Call trace: mutex_lock+0x18/0x60 hwmon_notify_event+0xfc/0x110 0xffffdde1cb7a0a90 0xffffdde1cb7a0b7c irq_thread_fn+0x2c/0xa0 irq_thread+0x134/0x240 kthread+0x178/0x190 ret_from_fork+0x10/0x20 Code: d503201f d503201f d2800001 aa0103e4 (c8e47c02) Jon Hunter reports that the exact call sequence is: hwmon_notify_event() --> hwmon_thermal_notify() --> thermal_zone_device_update() --> update_temperature() --> mutex_lock() The hwmon core needs to handle all errors returned from calls to devm_thermal_zone_of_sensor_register(). If the call fails with -ENODEV, report that the sensor was not attached to a thermal zone but continue to register the hwmon device.

In the Linux kernel, the following vulnerability has been resolved: ice: fix concurrent reset and removal of VFs Commit c503e63200c6 ("ice: Stop processing VF messages during teardown") introduced a driver state flag, ICE_VF_DEINIT_IN_PROGRESS, which is intended to prevent some issues with concurrently handling messages from VFs while tearing down the VFs. This change was motivated by crashes caused while tearing down and bringing up VFs in rapid succession. It turns out that the fix actually introduces issues with the VF driver caused because the PF no longer responds to any messages sent by the VF during its .remove routine. This results in the VF potentially removing its DMA memory before the PF has shut down the device queues. Additionally, the fix doesn't actually resolve concurrency issues within the ice driver. It is possible for a VF to initiate a reset just prior to the ice driver removing VFs. This can result in the remove task concurrently operating while the VF is being reset. This results in similar memory corruption and panics purportedly fixed by that commit. Fix this concurrency at its root by protecting both the reset and removal flows using the existing VF cfg_lock. This ensures that we cannot remove the VF while any outstanding critical tasks such as a virtchnl message or a reset are occurring. This locking change also fixes the root cause originally fixed by commit c503e63200c6 ("ice: Stop processing VF messages during teardown"), so we can simply revert it. Note that I kept these two changes together because simply reverting the original commit alone would leave the driver vulnerable to worse race conditions.

In the Linux kernel, the following vulnerability has been resolved: bpf: Add schedule points in batch ops syzbot reported various soft lockups caused by bpf batch operations. INFO: task kworker/1:1:27 blocked for more than 140 seconds. INFO: task hung in rcu_barrier Nothing prevents batch ops to process huge amount of data, we need to add schedule points in them. Note that maybe_wait_bpf_programs(map) calls from generic_map_delete_batch() can be factorized by moving the call after the loop. This will be done later in -next tree once we get this fix merged, unless there is strong opinion doing this optimization sooner.

In the Linux kernel, the following vulnerability has been resolved: CDC-NCM: avoid overflow in sanity checking A broken device may give an extreme offset like 0xFFF0 and a reasonable length for a fragment. In the sanity check as formulated now, this will create an integer overflow, defeating the sanity check. Both offset and offset + len need to be checked in such a manner that no overflow can occur. And those quantities should be unsigned.

In the Linux kernel, the following vulnerability has been resolved: io_uring: add a schedule point in io_add_buffers() Looping ~65535 times doing kmalloc() calls can trigger soft lockups, especially with DEBUG features (like KASAN). [ 253.536212] watchdog: BUG: soft lockup - CPU#64 stuck for 26s! [b219417889:12575] [ 253.544433] Modules linked in: vfat fat i2c_mux_pca954x i2c_mux spidev cdc_acm xhci_pci xhci_hcd sha3_generic gq(O) [ 253.544451] CPU: 64 PID: 12575 Comm: b219417889 Tainted: G S O 5.17.0-smp-DEV #801 [ 253.544457] RIP: 0010:kernel_text_address (./include/asm-generic/sections.h:192 ./include/linux/kallsyms.h:29 kernel/extable.c:67 kernel/extable.c:98) [ 253.544464] Code: 0f 93 c0 48 c7 c1 e0 63 d7 a4 48 39 cb 0f 92 c1 20 c1 0f b6 c1 5b 5d c3 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 53 48 89 fb <48> c7 c0 00 00 80 a0 41 be 01 00 00 00 48 39 c7 72 0c 48 c7 c0 40 [ 253.544468] RSP: 0018:ffff8882d8baf4c0 EFLAGS: 00000246 [ 253.544471] RAX: 1ffff1105b175e00 RBX: ffffffffa13ef09a RCX: 00000000a13ef001 [ 253.544474] RDX: ffffffffa13ef09a RSI: ffff8882d8baf558 RDI: ffffffffa13ef09a [ 253.544476] RBP: ffff8882d8baf4d8 R08: ffff8882d8baf5e0 R09: 0000000000000004 [ 253.544479] R10: ffff8882d8baf5e8 R11: ffffffffa0d59a50 R12: ffff8882eab20380 [ 253.544481] R13: ffffffffa0d59a50 R14: dffffc0000000000 R15: 1ffff1105b175eb0 [ 253.544483] FS: 00000000016d3380(0000) GS:ffff88af48c00000(0000) knlGS:0000000000000000 [ 253.544486] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 253.544488] CR2: 00000000004af0f0 CR3: 00000002eabfa004 CR4: 00000000003706e0 [ 253.544491] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 253.544492] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 253.544494] Call Trace: [ 253.544496] <TASK> [ 253.544498] ? io_queue_sqe (fs/io_uring.c:7143) [ 253.544505] __kernel_text_address (kernel/extable.c:78) [ 253.544508] unwind_get_return_address (arch/x86/kernel/unwind_frame.c:19) [ 253.544514] arch_stack_walk (arch/x86/kernel/stacktrace.c:27) [ 253.544517] ? io_queue_sqe (fs/io_uring.c:7143) [ 253.544521] stack_trace_save (kernel/stacktrace.c:123) [ 253.544527] ____kasan_kmalloc (mm/kasan/common.c:39 mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:515) [ 253.544531] ? ____kasan_kmalloc (mm/kasan/common.c:39 mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:515) [ 253.544533] ? __kasan_kmalloc (mm/kasan/common.c:524) [ 253.544535] ? kmem_cache_alloc_trace (./include/linux/kasan.h:270 mm/slab.c:3567) [ 253.544541] ? io_issue_sqe (fs/io_uring.c:4556 fs/io_uring.c:4589 fs/io_uring.c:6828) [ 253.544544] ? __io_queue_sqe (fs/io_uring.c:?) [ 253.544551] __kasan_kmalloc (mm/kasan/common.c:524) [ 253.544553] kmem_cache_alloc_trace (./include/linux/kasan.h:270 mm/slab.c:3567) [ 253.544556] ? io_issue_sqe (fs/io_uring.c:4556 fs/io_uring.c:4589 fs/io_uring.c:6828) [ 253.544560] io_issue_sqe (fs/io_uring.c:4556 fs/io_uring.c:4589 fs/io_uring.c:6828) [ 253.544564] ? __kasan_slab_alloc (mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469) [ 253.544567] ? __kasan_slab_alloc (mm/kasan/common.c:39 mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469) [ 253.544569] ? kmem_cache_alloc_bulk (mm/slab.h:732 mm/slab.c:3546) [ 253.544573] ? __io_alloc_req_refill (fs/io_uring.c:2078) [ 253.544578] ? io_submit_sqes (fs/io_uring.c:7441) [ 253.544581] ? __se_sys_io_uring_enter (fs/io_uring.c:10154 fs/io_uring.c:10096) [ 253.544584] ? __x64_sys_io_uring_enter (fs/io_uring.c:10096) [ 253.544587] ? do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) [ 253.544590] ? entry_SYSCALL_64_after_hwframe (??:?) [ 253.544596] __io_queue_sqe (fs/io_uring.c:?) [ 253.544600] io_queue_sqe (fs/io_uring.c:7143) [ 253.544603] io_submit_sqe (fs/io_uring.c:?) [ 253.544608] io_submit_sqes (fs/io_uring.c:?) [ 253.544612] __se_sys_io_uring_enter (fs/io_uring.c:10154 fs/io_uri ---truncated---

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: unregister flowtable hooks on netns exit Unregister flowtable hooks before they are releases via nf_tables_flowtable_destroy() otherwise hook core reports UAF. BUG: KASAN: use-after-free in nf_hook_entries_grow+0x5a7/0x700 net/netfilter/core.c:142 net/netfilter/core.c:142 Read of size 4 at addr ffff8880736f7438 by task syz-executor579/3666 CPU: 0 PID: 3666 Comm: syz-executor579 Not tainted 5.16.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] __dump_stack lib/dump_stack.c:88 [inline] lib/dump_stack.c:106 dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106 lib/dump_stack.c:106 print_address_description+0x65/0x380 mm/kasan/report.c:247 mm/kasan/report.c:247 __kasan_report mm/kasan/report.c:433 [inline] __kasan_report mm/kasan/report.c:433 [inline] mm/kasan/report.c:450 kasan_report+0x19a/0x1f0 mm/kasan/report.c:450 mm/kasan/report.c:450 nf_hook_entries_grow+0x5a7/0x700 net/netfilter/core.c:142 net/netfilter/core.c:142 __nf_register_net_hook+0x27e/0x8d0 net/netfilter/core.c:429 net/netfilter/core.c:429 nf_register_net_hook+0xaa/0x180 net/netfilter/core.c:571 net/netfilter/core.c:571 nft_register_flowtable_net_hooks+0x3c5/0x730 net/netfilter/nf_tables_api.c:7232 net/netfilter/nf_tables_api.c:7232 nf_tables_newflowtable+0x2022/0x2cf0 net/netfilter/nf_tables_api.c:7430 net/netfilter/nf_tables_api.c:7430 nfnetlink_rcv_batch net/netfilter/nfnetlink.c:513 [inline] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] nfnetlink_rcv_batch net/netfilter/nfnetlink.c:513 [inline] net/netfilter/nfnetlink.c:652 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] net/netfilter/nfnetlink.c:652 nfnetlink_rcv+0x10e6/0x2550 net/netfilter/nfnetlink.c:652 net/netfilter/nfnetlink.c:652 __nft_release_hook() calls nft_unregister_flowtable_net_hooks() which only unregisters the hooks, then after RCU grace period, it is guaranteed that no packets add new entries to the flowtable (no flow offload rules and flowtable hooks are reachable from packet path), so it is safe to call nf_flow_table_free() which cleans up the remaining entries from the flowtable (both software and hardware) and it unbinds the flow_block.

In the Linux kernel, the following vulnerability has been resolved: nfp: flower: Fix a potential leak in nfp_tunnel_add_shared_mac() ida_simple_get() returns an id between min (0) and max (NFP_MAX_MAC_INDEX) inclusive. So NFP_MAX_MAC_INDEX (0xff) is a valid id. In order for the error handling path to work correctly, the 'invalid' value for 'ida_idx' should not be in the 0..NFP_MAX_MAC_INDEX range, inclusive. So set it to -1.

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: fix memory leak during stateful obj update stateful objects can be updated from the control plane. The transaction logic allocates a temporary object for this purpose. The ->init function was called for this object, so plain kfree() leaks resources. We must call ->destroy function of the object. nft_obj_destroy does this, but it also decrements the module refcount, but the update path doesn't increment it. To avoid special-casing the update object release, do module_get for the update case too and release it via nft_obj_destroy().

In the Linux kernel, the following vulnerability has been resolved: configfs: fix a race in configfs_{,un}register_subsystem() When configfs_register_subsystem() or configfs_unregister_subsystem() is executing link_group() or unlink_group(), it is possible that two processes add or delete list concurrently. Some unfortunate interleavings of them can cause kernel panic. One of cases is: A --> B --> C --> D A <-- B <-- C <-- D delete list_head *B | delete list_head *C --------------------------------|----------------------------------- configfs_unregister_subsystem | configfs_unregister_subsystem unlink_group | unlink_group unlink_obj | unlink_obj list_del_init | list_del_init __list_del_entry | __list_del_entry __list_del | __list_del // next == C | next->prev = prev | | next->prev = prev prev->next = next | | // prev == B | prev->next = next Fix this by adding mutex when calling link_group() or unlink_group(), but parent configfs_subsystem is NULL when config_item is root. So I create a mutex configfs_subsystem_mutex.

In the Linux kernel, the following vulnerability has been resolved: RDMA/ib_srp: Fix a deadlock Remove the flush_workqueue(system_long_wq) call since flushing system_long_wq is deadlock-prone and since that call is redundant with a preceding cancel_work_sync()

In the Linux kernel, the following vulnerability has been resolved: iio: adc: men_z188_adc: Fix a resource leak in an error handling path If iio_device_register() fails, a previous ioremap() is left unbalanced. Update the error handling path and add the missing iounmap() call, as already done in the remove function.

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: rndis: add spinlock for rndis response list There's no lock for rndis response list. It could cause list corruption if there're two different list_add at the same time like below. It's better to add in rndis_add_response / rndis_free_response / rndis_get_next_response to prevent any race condition on response list. [ 361.894299] [1: irq/191-dwc3:16979] list_add corruption. next->prev should be prev (ffffff80651764d0), but was ffffff883dc36f80. (next=ffffff80651764d0). [ 361.904380] [1: irq/191-dwc3:16979] Call trace: [ 361.904391] [1: irq/191-dwc3:16979] __list_add_valid+0x74/0x90 [ 361.904401] [1: irq/191-dwc3:16979] rndis_msg_parser+0x168/0x8c0 [ 361.904409] [1: irq/191-dwc3:16979] rndis_command_complete+0x24/0x84 [ 361.904417] [1: irq/191-dwc3:16979] usb_gadget_giveback_request+0x20/0xe4 [ 361.904426] [1: irq/191-dwc3:16979] dwc3_gadget_giveback+0x44/0x60 [ 361.904434] [1: irq/191-dwc3:16979] dwc3_ep0_complete_data+0x1e8/0x3a0 [ 361.904442] [1: irq/191-dwc3:16979] dwc3_ep0_interrupt+0x29c/0x3dc [ 361.904450] [1: irq/191-dwc3:16979] dwc3_process_event_entry+0x78/0x6cc [ 361.904457] [1: irq/191-dwc3:16979] dwc3_process_event_buf+0xa0/0x1ec [ 361.904465] [1: irq/191-dwc3:16979] dwc3_thread_interrupt+0x34/0x5c

In the Linux kernel, the following vulnerability has been resolved: thermal: int340x: fix memory leak in int3400_notify() It is easy to hit the below memory leaks in my TigerLake platform: unreferenced object 0xffff927c8b91dbc0 (size 32): comm "kworker/0:2", pid 112, jiffies 4294893323 (age 83.604s) hex dump (first 32 bytes): 4e 41 4d 45 3d 49 4e 54 33 34 30 30 20 54 68 65 NAME=INT3400 The 72 6d 61 6c 00 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 rmal.kkkkkkkkkk. backtrace: [<ffffffff9c502c3e>] __kmalloc_track_caller+0x2fe/0x4a0 [<ffffffff9c7b7c15>] kvasprintf+0x65/0xd0 [<ffffffff9c7b7d6e>] kasprintf+0x4e/0x70 [<ffffffffc04cb662>] int3400_notify+0x82/0x120 [int3400_thermal] [<ffffffff9c8b7358>] acpi_ev_notify_dispatch+0x54/0x71 [<ffffffff9c88f1a7>] acpi_os_execute_deferred+0x17/0x30 [<ffffffff9c2c2c0a>] process_one_work+0x21a/0x3f0 [<ffffffff9c2c2e2a>] worker_thread+0x4a/0x3b0 [<ffffffff9c2cb4dd>] kthread+0xfd/0x130 [<ffffffff9c201c1f>] ret_from_fork+0x1f/0x30 Fix it by calling kfree() accordingly.

In the Linux kernel, the following vulnerability has been resolved: btrfs: prevent copying too big compressed lzo segment Compressed length can be corrupted to be a lot larger than memory we have allocated for buffer. This will cause memcpy in copy_compressed_segment to write outside of allocated memory. This mostly results in stuck read syscall but sometimes when using btrfs send can get #GP kernel: general protection fault, probably for non-canonical address 0x841551d5c1000: 0000 [#1] PREEMPT SMP NOPTI kernel: CPU: 17 PID: 264 Comm: kworker/u256:7 Tainted: P OE 5.17.0-rc2-1 #12 kernel: Workqueue: btrfs-endio btrfs_work_helper [btrfs] kernel: RIP: 0010:lzo_decompress_bio (./include/linux/fortify-string.h:225 fs/btrfs/lzo.c:322 fs/btrfs/lzo.c:394) btrfs Code starting with the faulting instruction =========================================== 0:* 48 8b 06 mov (%rsi),%rax <-- trapping instruction 3: 48 8d 79 08 lea 0x8(%rcx),%rdi 7: 48 83 e7 f8 and $0xfffffffffffffff8,%rdi b: 48 89 01 mov %rax,(%rcx) e: 44 89 f0 mov %r14d,%eax 11: 48 8b 54 06 f8 mov -0x8(%rsi,%rax,1),%rdx kernel: RSP: 0018:ffffb110812efd50 EFLAGS: 00010212 kernel: RAX: 0000000000001000 RBX: 000000009ca264c8 RCX: ffff98996e6d8ff8 kernel: RDX: 0000000000000064 RSI: 000841551d5c1000 RDI: ffffffff9500435d kernel: RBP: ffff989a3be856c0 R08: 0000000000000000 R09: 0000000000000000 kernel: R10: 0000000000000000 R11: 0000000000001000 R12: ffff98996e6d8000 kernel: R13: 0000000000000008 R14: 0000000000001000 R15: 000841551d5c1000 kernel: FS: 0000000000000000(0000) GS:ffff98a09d640000(0000) knlGS:0000000000000000 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kernel: CR2: 00001e9f984d9ea8 CR3: 000000014971a000 CR4: 00000000003506e0 kernel: Call Trace: kernel: <TASK> kernel: end_compressed_bio_read (fs/btrfs/compression.c:104 fs/btrfs/compression.c:1363 fs/btrfs/compression.c:323) btrfs kernel: end_workqueue_fn (fs/btrfs/disk-io.c:1923) btrfs kernel: btrfs_work_helper (fs/btrfs/async-thread.c:326) btrfs kernel: process_one_work (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:212 ./include/trace/events/workqueue.h:108 kernel/workqueue.c:2312) kernel: worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2455) kernel: ? process_one_work (kernel/workqueue.c:2397) kernel: kthread (kernel/kthread.c:377) kernel: ? kthread_complete_and_exit (kernel/kthread.c:332) kernel: ret_from_fork (arch/x86/entry/entry_64.S:301) kernel: </TASK>

In the Linux kernel, the following vulnerability has been resolved: riscv: fix oops caused by irqsoff latency tracer The trace_hardirqs_{on,off}() require the caller to setup frame pointer properly. This because these two functions use macro 'CALLER_ADDR1' (aka. __builtin_return_address(1)) to acquire caller info. If the $fp is used for other purpose, the code generated this macro (as below) could trigger memory access fault. 0xffffffff8011510e <+80>: ld a1,-16(s0) 0xffffffff80115112 <+84>: ld s2,-8(a1) # <-- paging fault here The oops message during booting if compiled with 'irqoff' tracer enabled: [ 0.039615][ T0] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000f8 [ 0.041925][ T0] Oops [#1] [ 0.042063][ T0] Modules linked in: [ 0.042864][ T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.17.0-rc1-00233-g9a20c48d1ed2 #29 [ 0.043568][ T0] Hardware name: riscv-virtio,qemu (DT) [ 0.044343][ T0] epc : trace_hardirqs_on+0x56/0xe2 [ 0.044601][ T0] ra : restore_all+0x12/0x6e [ 0.044721][ T0] epc : ffffffff80126a5c ra : ffffffff80003b94 sp : ffffffff81403db0 [ 0.044801][ T0] gp : ffffffff8163acd8 tp : ffffffff81414880 t0 : 0000000000000020 [ 0.044882][ T0] t1 : 0098968000000000 t2 : 0000000000000000 s0 : ffffffff81403de0 [ 0.044967][ T0] s1 : 0000000000000000 a0 : 0000000000000001 a1 : 0000000000000100 [ 0.045046][ T0] a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000 [ 0.045124][ T0] a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000054494d45 [ 0.045210][ T0] s2 : ffffffff80003b94 s3 : ffffffff81a8f1b0 s4 : ffffffff80e27b50 [ 0.045289][ T0] s5 : ffffffff81414880 s6 : ffffffff8160fa00 s7 : 00000000800120e8 [ 0.045389][ T0] s8 : 0000000080013100 s9 : 000000000000007f s10: 0000000000000000 [ 0.045474][ T0] s11: 0000000000000000 t3 : 7fffffffffffffff t4 : 0000000000000000 [ 0.045548][ T0] t5 : 0000000000000000 t6 : ffffffff814aa368 [ 0.045620][ T0] status: 0000000200000100 badaddr: 00000000000000f8 cause: 000000000000000d [ 0.046402][ T0] [<ffffffff80003b94>] restore_all+0x12/0x6e This because the $fp(aka. $s0) register is not used as frame pointer in the assembly entry code. resume_kernel: REG_L s0, TASK_TI_PREEMPT_COUNT(tp) bnez s0, restore_all REG_L s0, TASK_TI_FLAGS(tp) andi s0, s0, _TIF_NEED_RESCHED beqz s0, restore_all call preempt_schedule_irq j restore_all To fix above issue, here we add one extra level wrapper for function trace_hardirqs_{on,off}() so they can be safely called by low level entry code.

In the Linux kernel, the following vulnerability has been resolved: btrfs: get rid of warning on transaction commit when using flushoncommit When using the flushoncommit mount option, during almost every transaction commit we trigger a warning from __writeback_inodes_sb_nr(): $ cat fs/fs-writeback.c: (...) static void __writeback_inodes_sb_nr(struct super_block *sb, ... { (...) WARN_ON(!rwsem_is_locked(&sb->s_umount)); (...) } (...) The trace produced in dmesg looks like the following: [947.473890] WARNING: CPU: 5 PID: 930 at fs/fs-writeback.c:2610 __writeback_inodes_sb_nr+0x7e/0xb3 [947.481623] Modules linked in: nfsd nls_cp437 cifs asn1_decoder cifs_arc4 fscache cifs_md4 ipmi_ssif [947.489571] CPU: 5 PID: 930 Comm: btrfs-transacti Not tainted 95.16.3-srb-asrock-00001-g36437ad63879 #186 [947.497969] RIP: 0010:__writeback_inodes_sb_nr+0x7e/0xb3 [947.502097] Code: 24 10 4c 89 44 24 18 c6 (...) [947.519760] RSP: 0018:ffffc90000777e10 EFLAGS: 00010246 [947.523818] RAX: 0000000000000000 RBX: 0000000000963300 RCX: 0000000000000000 [947.529765] RDX: 0000000000000000 RSI: 000000000000fa51 RDI: ffffc90000777e50 [947.535740] RBP: ffff888101628a90 R08: ffff888100955800 R09: ffff888100956000 [947.541701] R10: 0000000000000002 R11: 0000000000000001 R12: ffff888100963488 [947.547645] R13: ffff888100963000 R14: ffff888112fb7200 R15: ffff888100963460 [947.553621] FS: 0000000000000000(0000) GS:ffff88841fd40000(0000) knlGS:0000000000000000 [947.560537] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [947.565122] CR2: 0000000008be50c4 CR3: 000000000220c000 CR4: 00000000001006e0 [947.571072] Call Trace: [947.572354] <TASK> [947.573266] btrfs_commit_transaction+0x1f1/0x998 [947.576785] ? start_transaction+0x3ab/0x44e [947.579867] ? schedule_timeout+0x8a/0xdd [947.582716] transaction_kthread+0xe9/0x156 [947.585721] ? btrfs_cleanup_transaction.isra.0+0x407/0x407 [947.590104] kthread+0x131/0x139 [947.592168] ? set_kthread_struct+0x32/0x32 [947.595174] ret_from_fork+0x22/0x30 [947.597561] </TASK> [947.598553] ---[ end trace 644721052755541c ]--- This is because we started using writeback_inodes_sb() to flush delalloc when committing a transaction (when using -o flushoncommit), in order to avoid deadlocks with filesystem freeze operations. This change was made by commit ce8ea7cc6eb313 ("btrfs: don't call btrfs_start_delalloc_roots in flushoncommit"). After that change we started producing that warning, and every now and then a user reports this since the warning happens too often, it spams dmesg/syslog, and a user is unsure if this reflects any problem that might compromise the filesystem's reliability. We can not just lock the sb->s_umount semaphore before calling writeback_inodes_sb(), because that would at least deadlock with filesystem freezing, since at fs/super.c:freeze_super() sync_filesystem() is called while we are holding that semaphore in write mode, and that can trigger a transaction commit, resulting in a deadlock. It would also trigger the same type of deadlock in the unmount path. Possibly, it could also introduce some other locking dependencies that lockdep would report. To fix this call try_to_writeback_inodes_sb() instead of writeback_inodes_sb(), because that will try to read lock sb->s_umount and then will only call writeback_inodes_sb() if it was able to lock it. This is fine because the cases where it can't read lock sb->s_umount are during a filesystem unmount or during a filesystem freeze - in those cases sb->s_umount is write locked and sync_filesystem() is called, which calls writeback_inodes_sb(). In other words, in all cases where we can't take a read lock on sb->s_umount, writeback is already being triggered elsewhere. An alternative would be to call btrfs_start_delalloc_roots() with a number of pages different from LONG_MAX, for example matching the number of delalloc bytes we currently have, in ---truncated---