OESA-2021-1176

The Linux Kernel, the operating system core itself.

Security Fix(es):

An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c performs undesirable out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-f232326f6966. This affects pointer types that do not define a ptr_limit.(CVE-2020-27170)

An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c has an off-by-one error (with a resultant integer underflow) affecting out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory, aka CID-10d2bb2e6b1d.(CVE-2020-27171)

rtwwxsetscan in drivers/staging/rtl8188eu/osdep/ioctl_linux.c in the Linux kernel through 5.11.6 allows writing beyond the end of the ->ssid[] array. NOTE: from the perspective of kernel.org releases, CVE IDs are not normally used for drivers/staging/* (unfinished work); however, system integrators may have situations in which a drivers/staging issue is relevant to their own customer base.(CVE-2021-28660)

A race condition was discovered in getoldroot in fs/btrfs/ctree.c in the Linux kernel through 5.11.8. It allows attackers to cause a denial of service (BUG) because of a lack of locking on an extent buffer before a cloning operation, aka CID-dbcc7d57bffc.(CVE-2021-28964)

In drivers/pci/hotplug/rpadlparsysfs.c in the Linux kernel through 5.11.8, the RPA PCI Hotplug driver has a user-tolerable buffer overflow when writing a new device name to the driver from userspace, allowing userspace to write data to the kernel stack frame directly. This occurs because addslotstore and removeslotstore mishandle drcname '\0' termination, aka CID-cc7a0bb058b8.(CVE-2021-28972)

In intelpmudrainpebsnhm in arch/x86/events/intel/ds.c in the Linux kernel through 5.11.8 on some Haswell CPUs, userspace applications (such as perf-fuzzer) can cause a system crash because the PEBS status in a PEBS record is mishandled, aka CID-d88d05a9e0b6.(CVE-2021-28971)

An out-of-bounds (OOB) memory access flaw was found in x25bind in net/x25/afx25.c in the Linux kernel. A bounds check failure allows a local attacker with a user account on the system to gain access to out-of-bounds memory, leading to a system crash or a leak of internal kernel information. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.(CVE-2020-35519)

There is a flaw reported in drivers/gpu/drm/nouveau/nouveausgdma.c in nouveausgdmacreatettm in Nouveau DRM subsystem. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker with a local account with a root privilege, can leverage this vulnerability to escalate privileges and execute code in the context of the kernel.(CVE-2021-20292)

The bpf verifier in the Linux kernel did not properly handle mod32 destination register truncation when the source register was known to be 0. A local attacker with the ability to load bpf programs could use this gain out-of-bounds reads in kernel memory leading to information disclosure (kernel memory), and possibly out-of-bounds writes that could potentially lead to code execution. This issue was addressed in the upstream kernel in commit 9b00f1b78809 ("bpf: Fix truncation handling for mod32 dst reg wrt zero") and in Linux stable kernels 5.11.2, 5.10.19, and 5.4.101.(CVE-2021-3444)

An issue was discovered in the Linux kernel before 5.11.7. usbipsockfdstore in drivers/usb/usbip/stub_dev.c allows attackers to cause a denial of service (GPF) because the stub-up sequence has race conditions during an update of the local and shared status, aka CID-9380afd6df70.(CVE-2021-29265)

An issue was discovered in the Linux kernel through 5.11.10. drivers/net/ethernet/freescale/gianfar.c in the Freescale Gianfar Ethernet driver allows attackers to cause a system crash because a negative fragment size is calculated in situations involving an rx queue overrun when jumbo packets are used and NAPI is enabled, aka CID-d8861bab48b6.(CVE-2021-29264)

An issue was discovered in the Linux kernel before 5.11.11. qrtr_recvmsg in net/qrtr/qrtr.c allows attackers to obtain sensitive information from kernel memory because of a partially uninitialized data structure, aka CID-50535249f624.(CVE-2021-29647)

An issue was discovered in the Linux kernel before 5.11.11. The netfilter subsystem allows attackers to cause a denial of service (panic) because net/netfilter/xtables.c and include/linux/netfilter/xtables.h lack a full memory barrier upon the assignment of a new table value, aka CID-175e476b8cdf.(CVE-2021-29650)

The fix for XSA-365 includes initialization of pointers such that subsequent cleanup code wouldn't use uninitialized or stale values. This initialization went too far and may under certain conditions also overwrite pointers which are in need of cleaning up. The lack of cleanup would result in leaking persistent grants. The leak in turn would prevent fully cleaning up after a respective guest has died, leaving around zombie domains. All Linux versions having the fix for XSA-365 applied are vulnerable. XSA-365 was classified to affect versions back to at least 3.11.(CVE-2021-28688)

BPF JIT compilers in the Linux kernel through 5.11.12 have incorrect computation of branch displacements, allowing them to execute arbitrary code within the kernel context. This affects arch/x86/net/bpfjitcomp.c and arch/x86/net/bpfjitcomp32.c.(CVE-2021-29154)

An issue was discovered in the Linux kernel before 5.8.10. virt/kvm/kvmmain.c has a kvmiobusunregister_dev memory leak upon a kmalloc failure, aka CID-f65886606c2d.(CVE-2020-36312)

An issue was discovered in the Linux kernel before 5.9. arch/x86/kvm/svm/sev.c allows attackers to cause a denial of service (soft lockup) by triggering destruction of a large SEV VM (which requires unregistering many encrypted regions), aka CID-7be74942f184.(CVE-2020-36311)

An issue was discovered in the FUSE filesystem implementation in the Linux kernel before 5.10.6, aka CID-5d069dbe8aaf. fusedogetattr() calls makebadinode() in inappropriate situations, causing a system crash. NOTE: the original fix for this vulnerability was incomplete, and its incompleteness is tracked as CVE-2021-28950.(CVE-2020-36322)

An issue was discovered in the Linux kernel through 5.11.x. kernel/bpf/verifier.c performs undesirable out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory. Specifically, for sequences of pointer arithmetic operations, the pointer modification performed by the first operation is not correctly accounted for when restricting subsequent operations.(CVE-2021-29155)

A race condition in Linux kernel SCTP sockets (net/sctp/socket.c) before 5.12-rc8 can lead to kernel privilege escalation from the context of a network service or an unprivileged process. If sctpdestroysock is called without socknet(sk)->sctp.addrwqlock then an element is removed from the autoasconfsplist list without any proper locking. This can be exploited by an attacker with network service privileges to escalate to root or from the context of an unprivileged user directly if a BPFCGROUPINETSOCK_CREATE is attached which denies creation of some SCTP socket.(CVE-2021-23133)

An out-of-bounds (OOB) memory access flaw was found in fs/f2fs/node.c in the f2fs module in the Linux kernel in versions before 5.12.0-rc4. A bounds check failure allows a local attacker to gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information. The highest threat from this vulnerability is to system availability.(CVE-2021-3506)

An issue was discovered in the Linux kernel before 5.11.3 when a webcam device exists. video_usercopy in drivers/media/v4l2-core/v4l2-ioctl.c has a memory leak for large arguments, aka CID-fb18802a338b.(CVE-2021-30002)

A flaw was found in the Nosy driver in the Linux kernel. This issue allows a device to be inserted twice into a doubly-linked list, leading to a use-after-free when one of these devices is removed. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. Versions before kernel 5.12-rc6 are affected(CVE-2021-3483)

An out-of-bounds (OOB) memory write flaw was found in listdevices in drivers/md/dm-ioctl.c in the Multi-device driver module in the Linux kernel before 5.12. A bound check failure allows an attacker with special user (CAPSYS_ADMIN) privilege to gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information. The highest threat from this vulnerability is to system availability.(CVE-2021-31916)

kernel/bpf/verifier.c in the Linux kernel through 5.12.1 performs undesirable speculative loads, leading to disclosure of stack content via side-channel attacks, aka CID-801c6058d14a. The specific concern is not protecting the BPF stack area against speculative loads. Also, the BPF stack can contain uninitialized data that might represent sensitive information previously operated on by the kernel.(CVE-2021-31829)

net/bluetooth/hci_request.c in the Linux kernel through 5.12.2 has a race condition for removal of the HCI controller.(CVE-2021-32399)

Use After Free vulnerability in nfc sockets in the Linux Kernel before 5.12.4 allows local attackers to elevate their privileges. In typical configurations, the issue can only be triggered by a privileged local user with the CAPNETRAW capability.(CVE-2021-23134)

In the Linux kernel before 5.12.4, net/bluetooth/hcievent.c has a use-after-free when destroying an hcichan, aka CID-5c4c8c954409. This leads to writing an arbitrary value.(CVE-2021-33034)

The Linux kernel before 5.11.14 has a use-after-free in cipsov4genopt in net/ipv4/cipso_ipv4.c because the CIPSO and CALIPSO refcounting for the DOI definitions is mishandled, aka CID-ad5d07f4a9cd. This leads to writing an arbitrary value.(CVE-2021-33033)

kernel/bpf/verifier.c in the Linux kernel through 5.12.7 enforces incorrect limits for pointer arithmetic operations, aka CID-bb01a1bba579. This can be abused to perform out-of-bounds reads and writes in kernel memory, leading to local privilege escalation to root. In particular, there is a corner case where the off reg causes a masking direction change, which then results in an incorrect final aux->alu_limit.(CVE-2021-33200)

A flaw double-free memory corruption in the Linux kernel HCI device initialization subsystem was found in the way user attach malicious HCI TTY Bluetooth device. A local user could use this flaw to crash the system. This flaw affects all the Linux kernel versions starting from 3.13.(CVE-2021-3564)

An issue was discovered in the Linux kernel before 5.8.1. net/bluetooth/hcievent.c has a slab out-of-bounds read in hciextendedinquiryresult_evt, aka CID-51c19bf3d5cf.(CVE-2020-36386)