In the Linux kernel, the following vulnerability has been resolved:
dmaengine: Fix double increment of client_count in dma_chan_get()
The first time dma_chan_get() is called for a channel the channel client_count is incorrectly incremented twice for public channels, first in balance_ref_count(), and again prior to returning. This results in an incorrect client count which will lead to the channel resources not being freed when they should be. A simple test of repeated module load and unload of async_tx on a Dell Power Edge R7425 also shows this resulting in a kref underflow warning.
[ 124.329662] async_tx: api initialized (async) [ 129.000627] async_tx: api initialized (async) [ 130.047839] ------------[ cut here ]------------ [ 130.052472] refcount_t: underflow; use-after-free. [ 130.057279] WARNING: CPU: 3 PID: 19364 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x110 [ 130.065811] Modules linked in: async_tx(-) rfkill intel_rapl_msr intel_rapl_common amd64_edac edac_mce_amd ipmi_ssif kvm_amd dcdbas kvm mgag200 drm_shmem_helper acpi_ipmi irqbypass drm_kms_helper ipmi_si syscopyarea sysfillrect rapl pcspkr ipmi_devintf sysimgblt fb_sys_fops k10temp i2c_piix4 ipmi_msghandler acpi_power_meter acpi_cpufreq vfat fat drm fuse xfs libcrc32c sd_mod t10_pi sg ahci crct10dif_pclmul libahci crc32_pclmul crc32c_intel ghash_clmulni_intel igb megaraid_sas i40e libata i2c_algo_bit ccp sp5100_tco dca dm_mirror dm_region_hash dm_log dm_mod [last unloaded: async_tx] [ 130.11…
In the Linux kernel, the following vulnerability has been resolved:
dmaengine: Fix double increment of client_count in dma_chan_get()
The first time dma_chan_get() is called for a channel the channel client_count is incorrectly incremented twice for public channels, first in balance_ref_count(), and again prior to returning. This results in an incorrect client count which will lead to the channel resources not being freed when they should be. A simple test of repeated module load and unload of async_tx on a Dell Power Edge R7425 also shows this resulting in a kref underflow warning.
[ 124.329662] async_tx: api initialized (async) [ 129.000627] async_tx: api initialized (async) [ 130.047839] ------------[ cut here ]------------ [ 130.052472] refcount_t: underflow; use-after-free. [ 130.057279] WARNING: CPU: 3 PID: 19364 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x110 [ 130.065811] Modules linked in: async_tx(-) rfkill intel_rapl_msr intel_rapl_common amd64_edac edac_mce_amd ipmi_ssif kvm_amd dcdbas kvm mgag200 drm_shmem_helper acpi_ipmi irqbypass drm_kms_helper ipmi_si syscopyarea sysfillrect rapl pcspkr ipmi_devintf sysimgblt fb_sys_fops k10temp i2c_piix4 ipmi_msghandler acpi_power_meter acpi_cpufreq vfat fat drm fuse xfs libcrc32c sd_mod t10_pi sg ahci crct10dif_pclmul libahci crc32_pclmul crc32c_intel ghash_clmulni_intel igb megaraid_sas i40e libata i2c_algo_bit ccp sp5100_tco dca dm_mirror dm_region_hash dm_log dm_mod [last unloaded: async_tx] [ 130.11…
Affected: openEuler:20.03-LTS-SP4: kernel
The Linux Kernel, the operating system core itself. Security Fix(es):
In the Linux kernel, the following vulnerability has been resolved:
nfc: nci: add flush_workqueue to prevent uaf
Our detector found a concurrent use-after-free bug when detaching an NCI device. The main reason for this bug is the unexpected scheduling between the used delayed mechanism (timer and workqueue).
The race can be demonstrated below:
Thread-1 Thread-2 | nci_dev_up() | nci_open_device() | __nci_request(nci_reset_req) | nci_send_cmd | queue_work(cmd_work) nci_unregister_device() | nci_close_device() | ... del_timer_sync(cmd_timer)[1] | ... | Worker nci_free_device() | nci_cmd_work() kfree(ndev)[3] | mod_timer(cmd_timer)[2]
In short, the cleanup routine thought that the cmd_timer has already been detached by [1] but the mod_timer can re-attach the timer [2], even it is already released [3], resulting in UAF.
This UAF is easy to trigger, crash trace by POC is like below
[ 66.703713] ================================================================== [ 66.703974] BUG: KASAN: use-after-free in enqueue_timer+0x448/0x490 [ 66.703974] Write of size 8 at addr ffff888009fb7058 by task kworker/u4…
hw: cpu: AMD CPUs may transiently execute beyond unconditional direct branch kernel: ext4: kernel bug in ext4_write_inline_data_end() kernel: malicious data for FBIOPUT_VSCREENINFO ioctl may cause OOB write memory kernel: hwmon: (mlxreg-fan) Return non-zero value when fan current state is enforced from sysfs kernel: mlxsw: thermal: Fix out-of-bounds memory accesses kernel: mlxsw: spectrum: Protect driver from buggy firmware kernel: net: stmmac: fix tc flower deletion for VLAN priority Rx steering kernel: can: etas_es58x: es58x_rx_err_msg(): fix memory leak in error path kernel: possible race condition in drivers/tty/tty_buffers.c kernel: KVM: NULL pointer dereference in kvm_mmu_invpcid_gva kernel: use-after-free in free_pipe_info() could lead to privilege escalation kernel: KVM: nVMX: missing IBPB when exiting from nested guest can lead to Spectre v2 attacks kernel: netfilter: nf_conntrack_irc message handling issue kernel: race condition in xfrm_probe_algs can lead to OOB read/write kernel: out-of-bounds read in fib_nh_match of the file net/ipv4/fib_semantics.c kernel: race condition in hugetlb_no_page() in mm/hugetlb.c kernel: memory leak in ipv6_renew_options() kernel: data races around icsk->icsk_af_ops in do_ipv6_setsockopt kernel: data races around sk->sk_prot kernel: memory leak in l2cap_recv_acldata of the file net/bluetooth/l2cap_core.c kernel: denial of service in follow_page_pte in mm/gup.c due to poisoned pte entry kernel: use-after-free after failed devlink relo…
Security update for the Linux Kernel
Affected: Ubuntu:Pro:14.04:LTS: linux-azure, Ubuntu:Pro:14.04:LTS: linux-aws, Ubuntu:Pro:14.04:LTS: linux-lts-xenial, Ubuntu:Pro:16.04:LTS: linux-aws-hwe, Ubuntu:Pro:16.04:LTS: linux-azure, Ubuntu:Pro:16.04:LTS: linux-gcp, Ubuntu:Pro:16.04:LTS: linux-hwe, Ubuntu:Pro:16.04:LTS: linux-oracle, Ubuntu:Pro:16.04:LTS: linux, Ubuntu:Pro:16.04:LTS: linux-aws and 147 more
In the Linux kernel, the following vulnerability has been resolved: dmaengine: Fix double increment of client_count in dma_chan_get() The first time dma_chan_get() is called for a channel the channel client_count is incorrectly incremented twice for public channels, first in balance_ref_count(), and again prior to returning. This results in an incorrect client count which will lead to the channel resources not being freed when they should be. A simple test of repeated module load and unload of async_tx on a Dell Power Edge R7425 also shows this resulting in a kref underflow warning. [ 124.329662] async_tx: api initialized (async) [ 129.000627] async_tx: api initialized (async) [ 130.047839] ------------[ cut here ]------------ [ 130.052472] refcount_t: underflow; use-after-free. [ 130.057279] WARNING: CPU: 3 PID: 19364 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x110 [ 130.065811] Modules linked in: async_tx(-) rfkill intel_rapl_msr intel_rapl_common amd64_edac edac_mce_amd ipmi_ssif kvm_amd dcdbas kvm mgag200 drm_shmem_helper acpi_ipmi irqbypass drm_kms_helper ipmi_si syscopyarea sysfillrect rapl pcspkr ipmi_devintf sysimgblt fb_sys_fops k10temp i2c_piix4 ipmi_msghandler acpi_power_meter acpi_cpufreq vfat fat drm fuse xfs libcrc32c sd_mod t10_pi sg ahci crct10dif_pclmul libahci crc32_pclmul crc32c_intel ghash_clmulni_intel igb megaraid_sas i40e libata i2c_algo_bit ccp sp5100_tco dca dm_mirror dm_region_hash dm_log dm_mod [last unloaded: async_tx] [ 130.11736…
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen oder nicht spezifizierte Effekte zu erzielen.