Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: ax25: fix incorrect dev_tracker usage While investigating a separate rose issue [1], and enabling CONFIG_NET_DEV_REFCNT_TRACKER=y, Bernard reported an orthogonal ax25 issue [2] An ax25_dev can be used by one (or many) struct ax25_cb. We thus need different dev_tracker, one per struct ax25_cb. After this patch is applied, we are able to focus on rose. [1] https://lore.kernel.org/netdev/fb7544a1-f42e-9254-18cc-c9b071f4ca70@free.fr/ [2] [ 205.798723] reference already released. [ 205.798732] allocated in: [ 205.798734] ax25_bind+0x1a2/0x230 [ax25] [ 205.798747] __sys_bind+0xea/0x110 [ 205.798753] __x64_sys_bind+0x18/0x20 [ 205.798758] do_syscall_64+0x5c/0x80 [ 205.798763] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 205.798768] freed in: [ 205.798770] ax25_release+0x115/0x370 [ax25] [ 205.798778] __sock_release+0x42/0xb0 [ 205.798782] sock_close+0x15/0x20 [ 205.798785] __fput+0x9f/0x260 [ 205.798789] ____fput+0xe/0x10 [ 205.798792] task_work_run+0x64/0xa0 [ 205.798798] exit_to_user_mode_prepare+0x18b/0x190 [ 205.798804] syscall_exit_to_user_mode+0x26/0x40 [ 205.798808] do_syscall_64+0x69/0x80 [ 205.798812] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 205.798827] ------------[ cut here ]------------ [ 205.798829] WARNING: CPU: 2 PID: 2605 at lib/ref_tracker.c:136 ref_tracker_free.cold+0x60/0x81 [ 205.798837] Modules linked in: rose netrom mkiss ax25 rfcomm cmac algif_hash algif_skcipher af_alg bnep snd_hda_codec_hdmi nls_iso8859_1 i915 rtw88_8821ce rtw88_8821c x86_pkg_temp_thermal rtw88_pci intel_powerclamp rtw88_core snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio coretemp snd_hda_intel kvm_intel snd_intel_dspcfg mac80211 snd_hda_codec kvm i2c_algo_bit drm_buddy drm_dp_helper btusb drm_kms_helper snd_hwdep btrtl snd_hda_core btbcm joydev crct10dif_pclmul btintel crc32_pclmul ghash_clmulni_intel mei_hdcp btmtk intel_rapl_msr aesni_intel bluetooth input_leds snd_pcm crypto_simd syscopyarea processor_thermal_device_pci_legacy sysfillrect cryptd intel_soc_dts_iosf snd_seq sysimgblt ecdh_generic fb_sys_fops rapl libarc4 processor_thermal_device intel_cstate processor_thermal_rfim cec snd_timer ecc snd_seq_device cfg80211 processor_thermal_mbox mei_me processor_thermal_rapl mei rc_core at24 snd intel_pch_thermal intel_rapl_common ttm soundcore int340x_thermal_zone video [ 205.798948] mac_hid acpi_pad sch_fq_codel ipmi_devintf ipmi_msghandler drm msr parport_pc ppdev lp parport ramoops pstore_blk reed_solomon pstore_zone efi_pstore ip_tables x_tables autofs4 hid_generic usbhid hid i2c_i801 i2c_smbus r8169 xhci_pci ahci libahci realtek lpc_ich xhci_pci_renesas [last unloaded: ax25] [ 205.798992] CPU: 2 PID: 2605 Comm: ax25ipd Not tainted 5.18.11-F6BVP #3 [ 205.798996] Hardware name: To be filled by O.E.M. To be filled by O.E.M./CK3, BIOS 5.011 09/16/2020 [ 205.798999] RIP: 0010:ref_tracker_free.cold+0x60/0x81 [ 205.799005] Code: e8 d2 01 9b ff 83 7b 18 00 74 14 48 c7 c7 2f d7 ff 98 e8 10 6e fc ff 8b 7b 18 e8 b8 01 9b ff 4c 89 ee 4c 89 e7 e8 5d fd 07 00 <0f> 0b b8 ea ff ff ff e9 30 05 9b ff 41 0f b6 f7 48 c7 c7 a0 fa 4e [ 205.799008] RSP: 0018:ffffaf5281073958 EFLAGS: 00010286 [ 205.799011] RAX: 0000000080000000 RBX: ffff9a0bd687ebe0 RCX: 0000000000000000 [ 205.799014] RDX: 0000000000000001 RSI: 0000000000000282 RDI: 00000000ffffffff [ 205.799016] RBP: ffffaf5281073a10 R08: 0000000000000003 R09: fffffffffffd5618 [ 205.799019] R10: 0000000000ffff10 R11: 000000000000000f R12: ffff9a0bc53384d0 [ 205.799022] R13: 0000000000000282 R14: 00000000ae000001 R15: 0000000000000001 [ 205.799024] FS: 0000000000000000(0000) GS:ffff9a0d0f300000(0000) knlGS:0000000000000000 [ 205.799028] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 205.799031] CR2: 00007ff6b8311554 CR3: 000000001ac10004 CR4: 00000000001706e0 [ 205.799033] Call Trace: [ 205.799035] <TASK> [ 205.799038] ? ax25_dev_device_down+0xd9/ ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: wifi: libertas: Fix possible refcount leak in if_usb_probe() usb_get_dev will be called before lbs_get_firmware_async which means that usb_put_dev need to be called when lbs_get_firmware_async fails.Show less

In the Linux kernel, the following vulnerability has been resolved: mtd: maps: Fix refcount leak in of_flash_probe_versatile of_find_matching_node_and_match() returns a node pointer with refcount incremented, we should use of_node_put() on it when not need anymore. Add missing of_node_put() to avoid refcount leak.Show less

In the Linux kernel, the following vulnerability has been resolved: mtd: maps: Fix refcount leak in ap_flash_init of_find_matching_node() returns a node pointer with refcount incremented, we should use of_node_put() on it when not need anymore. Add missing of_node_put() to avoid refcount leak.Show less

In the Linux kernel, the following vulnerability has been resolved: of: check previous kernel's ima-kexec-buffer against memory bounds Presently ima_get_kexec_buffer() doesn't check if the previous kernel's ima-kexec-buffer lies outside the addressable memory range. This can result in a kernel panic if the new kernel is booted with 'mem=X' arg and the ima-kexec-buffer was allocated beyond that range by the previous kernel. The panic is usually of the form below: $ sudo kexec --initrd initrd vmlinux --append='mem=16G' <snip> BUG: Unable to handle kernel data access on read at 0xc000c01fff7f0000 Faulting instruction address: 0xc000000000837974 Oops: Kernel access of bad area, sig: 11 [#1] <snip> NIP [c000000000837974] ima_restore_measurement_list+0x94/0x6c0 LR [c00000000083b55c] ima_load_kexec_buffer+0xac/0x160 Call Trace: [c00000000371fa80] [c00000000083b55c] ima_load_kexec_buffer+0xac/0x160 [c00000000371fb00] [c0000000020512c4] ima_init+0x80/0x108 [c00000000371fb70] [c0000000020514dc] init_ima+0x4c/0x120 [c00000000371fbf0] [c000000000012240] do_one_initcall+0x60/0x2c0 [c00000000371fcc0] [c000000002004ad0] kernel_init_freeable+0x344/0x3ec [c00000000371fda0] [c0000000000128a4] kernel_init+0x34/0x1b0 [c00000000371fe10] [c00000000000ce64] ret_from_kernel_thread+0x5c/0x64 Instruction dump: f92100b8 f92100c0 90e10090 910100a0 4182050c 282a0017 3bc00000 40810330 7c0802a6 fb610198 7c9b2378 f80101d0 <a1240000> 2c090001 40820614 e9240010 ---[ end trace 0000000000000000 ]--- Fix this issue by checking returned PFN range of previous kernel's ima-kexec-buffer with page_is_ram() to ensure correct memory bounds.Show less

In the Linux kernel, the following vulnerability has been resolved: mtd: partitions: Fix refcount leak in parse_redboot_of of_get_child_by_name() returns a node pointer with refcount incremented, we should use of_node_put() on it when not need anymore. Add missing of_node_put() to avoid refcount leak.Show less

In the Linux kernel, the following vulnerability has been resolved: PCI: microchip: Fix refcount leak in mc_pcie_init_irq_domains() of_get_next_child() returns a node pointer with refcount incremented, so we should use of_node_put() on it when we don't need it anymore. mc_pcie_init_irq_domains() only calls of_node_put() in the normal path, missing it in some error paths. Add missing of_node_put() to avoid refcount leak.Show less

In the Linux kernel, the following vulnerability has been resolved: HID: cp2112: prevent a buffer overflow in cp2112_xfer() Smatch warnings: drivers/hid/hid-cp2112.c:793 cp2112_xfer() error: __memcpy() 'data->block[1]' too small (33 vs 255) drivers/hid/hid-cp2112.c:793 cp2112_xfer() error: __memcpy() 'buf' too small (64 vs 255) The 'read_length' variable is provided by 'data->block[0]' which comes from user and it(read_length) can take a value between 0-255. Add an upper bound to 'read_length' variable to prevent a buffer overflow in memcpy().Show less

In the Linux kernel, the following vulnerability has been resolved: mtd: parsers: ofpart: Fix refcount leak in bcm4908_partitions_fw_offset of_find_node_by_path() returns a node pointer with refcount incremented, we should use of_node_put() on it when not need anymore. Add missing of_node_put() to avoid refcount leak.Show less

In the Linux kernel, the following vulnerability has been resolved: PCI: mediatek-gen3: Fix refcount leak in mtk_pcie_init_irq_domains() of_get_child_by_name() returns a node pointer with refcount incremented, so we should use of_node_put() on it when we don't need it anymore. Add missing of_node_put() to avoid refcount leak.Show less

In the Linux kernel, the following vulnerability has been resolved: usb: host: Fix refcount leak in ehci_hcd_ppc_of_probe of_find_compatible_node() returns a node pointer with refcount incremented, we should use of_node_put() on it when done. Add missing of_node_put() to avoid refcount leak.Show less

In the Linux kernel, the following vulnerability has been resolved: usb: ohci-nxp: Fix refcount leak in ohci_hcd_nxp_probe of_parse_phandle() returns a node pointer with refcount incremented, we should use of_node_put() on it when not need anymore. Add missing of_node_put() to avoid refcount leak.Show less

In the Linux kernel, the following vulnerability has been resolved: usb: cdns3: fix random warning message when driver load Warning log: [ 4.141392] Unexpected gfp: 0x4 (GFP_DMA32). Fixing up to gfp: 0xa20 (GFP_ATOMIC). Fix your code! [ 4.150340] CPU: 1 PID: 175 Comm: 1-0050 Not tainted 5.15.5-00039-g2fd9ae1b568c #20 [ 4.158010] Hardware name: Freescale i.MX8QXP MEK (DT) [ 4.163155] Call trace: [ 4.165600] dump_backtrace+0x0/0x1b0 [ 4.169286] show_stack+0x18/0x68 [ 4.172611] dump_stack_lvl+0x68/0x84 [ 4.176286] dump_stack+0x18/0x34 [ 4.179613] kmalloc_fix_flags+0x60/0x88 [ 4.183550] new_slab+0x334/0x370 [ 4.186878] ___slab_alloc.part.108+0x4d4/0x748 [ 4.191419] __slab_alloc.isra.109+0x30/0x78 [ 4.195702] kmem_cache_alloc+0x40c/0x420 [ 4.199725] dma_pool_alloc+0xac/0x1f8 [ 4.203486] cdns3_allocate_trb_pool+0xb4/0xd0 pool_alloc_page(struct dma_pool *pool, gfp_t mem_flags) { ... page = kmalloc(sizeof(*page), mem_flags); page->vaddr = dma_alloc_coherent(pool->dev, pool->allocation, &page->dma, mem_flags); ... } kmalloc was called with mem_flags, which is passed down in cdns3_allocate_trb_pool() and have GFP_DMA32 flags. kmall_fix_flags() report warning. GFP_DMA32 is not useful at all. dma_alloc_coherent() will handle DMA memory region correctly by pool->dev. GFP_DMA32 can be removed safely.Show less

In the Linux kernel, the following vulnerability has been resolved: driver core: fix potential deadlock in __driver_attach In __driver_attach function, There are also AA deadlock problem, like the commit b232b02bf3c2 ("driver core: fix deadlock in __device_attach"). stack like commit b232b02bf3c2 ("driver core: fix deadlock in __device_attach"). list below: In __driver_attach function, The lock holding logic is as follows: ... __driver_attach if (driver_allows_async_probing(drv)) device_lock(dev) // get lock dev async_schedule_dev(__driver_attach_async_helper, dev); // func async_schedule_node async_schedule_node_domain(func) entry = kzalloc(sizeof(struct async_entry), GFP_ATOMIC); /* when fail or work limit, sync to execute func, but __driver_attach_async_helper will get lock dev as will, which will lead to A-A deadlock. */ if (!entry || atomic_read(&entry_count) > MAX_WORK) { func; else queue_work_node(node, system_unbound_wq, &entry->work) device_unlock(dev) As above show, when it is allowed to do async probes, because of out of memory or work limit, async work is not be allowed, to do sync execute instead. it will lead to A-A deadlock because of __driver_attach_async_helper getting lock dev. Reproduce: and it can be reproduce by make the condition (if (!entry || atomic_read(&entry_count) > MAX_WORK)) untenable, like below: [ 370.785650] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 370.787154] task:swapper/0 state:D stack: 0 pid: 1 ppid: 0 flags:0x00004000 [ 370.788865] Call Trace: [ 370.789374] <TASK> [ 370.789841] __schedule+0x482/0x1050 [ 370.790613] schedule+0x92/0x1a0 [ 370.791290] schedule_preempt_disabled+0x2c/0x50 [ 370.792256] __mutex_lock.isra.0+0x757/0xec0 [ 370.793158] __mutex_lock_slowpath+0x1f/0x30 [ 370.794079] mutex_lock+0x50/0x60 [ 370.794795] __device_driver_lock+0x2f/0x70 [ 370.795677] ? driver_probe_device+0xd0/0xd0 [ 370.796576] __driver_attach_async_helper+0x1d/0xd0 [ 370.797318] ? driver_probe_device+0xd0/0xd0 [ 370.797957] async_schedule_node_domain+0xa5/0xc0 [ 370.798652] async_schedule_node+0x19/0x30 [ 370.799243] __driver_attach+0x246/0x290 [ 370.799828] ? driver_allows_async_probing+0xa0/0xa0 [ 370.800548] bus_for_each_dev+0x9d/0x130 [ 370.801132] driver_attach+0x22/0x30 [ 370.801666] bus_add_driver+0x290/0x340 [ 370.802246] driver_register+0x88/0x140 [ 370.802817] ? virtio_scsi_init+0x116/0x116 [ 370.803425] scsi_register_driver+0x1a/0x30 [ 370.804057] init_sd+0x184/0x226 [ 370.804533] do_one_initcall+0x71/0x3a0 [ 370.805107] kernel_init_freeable+0x39a/0x43a [ 370.805759] ? rest_init+0x150/0x150 [ 370.806283] kernel_init+0x26/0x230 [ 370.806799] ret_from_fork+0x1f/0x30 To fix the deadlock, move the async_schedule_dev outside device_lock, as we can see, in async_schedule_node_domain, the parameter of queue_work_node is system_unbound_wq, so it can accept concurrent operations. which will also not change the code logic, and will not lead to deadlock.Show less

In the Linux kernel, the following vulnerability has been resolved: kernfs: fix potential NULL dereference in __kernfs_remove When lockdep is enabled, lockdep_assert_held_write would cause potential NULL pointer dereference. Fix the following smatch warnings: fs/kernfs/dir.c:1353 __kernfs_remove() warn: variable dereferenced before check 'kn' (see line 1346)Show less

In the Linux kernel, the following vulnerability has been resolved: PCI: dwc: Deallocate EPC memory on dw_pcie_ep_init() errors If dw_pcie_ep_init() fails to perform any action after the EPC memory is initialized and the MSI memory region is allocated, the latter parts won't be undone thus causing a memory leak. Add a cleanup-on-error path to fix these leaks. [bhelgaas: commit log]Show less

In the Linux kernel, the following vulnerability has been resolved: dmaengine: sf-pdma: Add multithread support for a DMA channel When we get a DMA channel and try to use it in multiple threads it will cause oops and hanging the system. % echo 64 > /sys/module/dmatest/parameters/threads_per_chan % echo 10000 > /sys/module/dmatest/parameters/iterations % echo 1 > /sys/module/dmatest/parameters/run [ 89.480664] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a0 [ 89.488725] Oops [#1] [ 89.494708] CPU: 2 PID: 1008 Comm: dma0chan0-copy0 Not tainted 5.17.0-rc5 [ 89.509385] epc : vchan_find_desc+0x32/0x46 [ 89.513553] ra : sf_pdma_tx_status+0xca/0xd6 This happens because of data race. Each thread rewrite channels's descriptor as soon as device_prep_dma_memcpy() is called. It leads to the situation when the driver thinks that it uses right descriptor that actually is freed or substituted for other one. With current fixes a descriptor changes its value only when it has been used. A new descriptor is acquired from vc->desc_issued queue that is already filled with descriptors that are ready to be sent. Threads have no direct access to DMA channel descriptor. Now it is just possible to queue a descriptor for further processing.Show less

In the Linux kernel, the following vulnerability has been resolved: soundwire: revisit driver bind/unbind and callbacks In the SoundWire probe, we store a pointer from the driver ops into the 'slave' structure. This can lead to kernel oopses when unbinding codec drivers, e.g. with the following sequence to remove machine driver and codec driver. /sbin/modprobe -r snd_soc_sof_sdw /sbin/modprobe -r snd_soc_rt711 The full details can be found in the BugLink below, for reference the two following examples show different cases of driver ops/callbacks being invoked after the driver .remove(). kernel: BUG: kernel NULL pointer dereference, address: 0000000000000150 kernel: Workqueue: events cdns_update_slave_status_work [soundwire_cadence] kernel: RIP: 0010:mutex_lock+0x19/0x30 kernel: Call Trace: kernel: ? sdw_handle_slave_status+0x426/0xe00 [soundwire_bus 94ff184bf398570c3f8ff7efe9e32529f532e4ae] kernel: ? newidle_balance+0x26a/0x400 kernel: ? cdns_update_slave_status_work+0x1e9/0x200 [soundwire_cadence 1bcf98eebe5ba9833cd433323769ac923c9c6f82] kernel: BUG: unable to handle page fault for address: ffffffffc07654c8 kernel: Workqueue: pm pm_runtime_work kernel: RIP: 0010:sdw_bus_prep_clk_stop+0x6f/0x160 [soundwire_bus] kernel: Call Trace: kernel: <TASK> kernel: sdw_cdns_clock_stop+0xb5/0x1b0 [soundwire_cadence 1bcf98eebe5ba9833cd433323769ac923c9c6f82] kernel: intel_suspend_runtime+0x5f/0x120 [soundwire_intel aca858f7c87048d3152a4a41bb68abb9b663a1dd] kernel: ? dpm_sysfs_remove+0x60/0x60 This was not detected earlier in Intel tests since the tests first remove the parent PCI device and shut down the bus. The sequence above is a corner case which keeps the bus operational but without a driver bound. While trying to solve this kernel oopses, it became clear that the existing SoundWire bus does not deal well with the unbind case. Commit 528be501b7d4a ("soundwire: sdw_slave: add probe_complete structure and new fields") added a 'probed' status variable and a 'probe_complete' struct completion. This status is however not reset on remove and likewise the 'probe complete' is not re-initialized, so the bind/unbind/bind test cases would fail. The timeout used before the 'update_status' callback was also a bad idea in hindsight, there should really be no timing assumption as to if and when a driver is bound to a device. An initial draft was based on device_lock() and device_unlock() was tested. This proved too complicated, with deadlocks created during the suspend-resume sequences, which also use the same device_lock/unlock() as the bind/unbind sequences. On a CometLake device, a bad DSDT/BIOS caused spurious resumes and the use of device_lock() caused hangs during suspend. After multiple weeks or testing and painful reverse-engineering of deadlocks on different devices, we looked for alternatives that did not interfere with the device core. A bus notifier was used successfully to keep track of DRIVER_BOUND and DRIVER_UNBIND events. This solved the bind-unbind-bind case in tests, but it can still be defeated with a theoretical corner case where the memory is freed by a .remove while the callback is in use. The notifier only helps make sure the driver callbacks are valid, but not that the memory allocated in probe remains valid while the callbacks are invoked. This patch suggests the introduction of a new 'sdw_dev_lock' mutex protecting probe/remove and all driver callbacks. Since this mutex is 'local' to SoundWire only, it does not interfere with existing locks and does not create deadlocks. In addition, this patch removes the 'probe_complete' completion, instead we directly invoke the 'update_status' from the probe routine. That removes any sort of timing dependency and a much better support for the device/driver model, the driver could be bound before the bus started, or eons after the bus started and the hardware would be properly initialized in all cases. BugLink: https://github.com/thesofproject/linux/is ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: intel_th: Fix a resource leak in an error handling path If an error occurs after calling 'pci_alloc_irq_vectors()', 'pci_free_irq_vectors()' must be called as already done in the remove function.Show less