CVE-2021-20239

A flaw was found in the Linux kernel in versions before 5.4.92 in the BPF protocol. This flaw allows an attacker with a local account to leak information about kernel internal addresses. The highest threat from this vulnerability is to confidentiality.

A flaw was found in the Linux kernel in versions before 5.4.92 in the BPF protocol. This flaw allows an attacker with a local account to leak information about kernel internal addresses. The highest threat from this vulnerability is to confidentiality.

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: out-of-bounds reads in pinctrl subsystem (CVE-2020-0427)
• kernel: Improper input validation in some Intel(R) Ethernet E810 Adapter drivers (CVE-2020-24502)
• kernel: Insufficient access control in some Intel(R) Ethernet E810 Adapter drivers (CVE-2020-24503)
• kernel: Uncontrolled resource consumption in some Intel(R) Ethernet E810 Adapter drivers (CVE-2020-24504)
• kernel: Fragmentation cache not cleared on reconnection (CVE-2020-24586)
• kernel: Reassembling fragments encrypted under different keys (CVE-2020-24587)
• kernel: wifi frame payload being parsed incorrectly as an L2 frame (CVE-2020-24588)
• kernel: Forwarding EAPOL from unauthenticated wifi client (CVE-2020-26139)
• kernel: accepting plaintext data frames in protected networks (CVE-2020-26140)
• kernel: not verifying TKIP MIC of fragmented frames (CVE-2020-26141)
• kernel: accepting fragmented plaintext frames in protected networks (CVE-2020-26143)
• kernel: accepting unencrypted A-MSDU frames that start with RFC1042 header (CVE-2020-26144)
• kernel: accepting plaintext broadcast fragments as full frames (CVE-2020-26145)
• kernel: powerpc: RTAS calls can be used to compromise kernel integrity (CVE-2020-27777)
• kernel: locking inconsistency in tty_io.c and tty_jobctrl.c can lead to a read-after-free (CVE-2020-29660)
• kernel: buffer overflow in mwifiex_cmd_802_11_ad_hoc_start function via a long SSID value (CVE-2020-36158)
• kernel: slab out-of-bounds read in hci_extended_inquiry_result_evt() (CVE-2020-36386)
• kernel: Improper access control in BlueZ may allow information disclosure vulnerability. (CVE-2021-0129)
• kernel: Use-after-free in ndb_queue_rq() in drivers/block/nbd.c (CVE-2021-3348)
• kernel: Linux kernel eBPF RINGBUF map oversized allocation (CVE-2021-3489)
• kernel: double free in bluetooth subsystem when the HCI device initialization fails (CVE-2021-3564)
• kernel: use-after-free in function hci_sock_bound_ioctl() (CVE-2021-3573)
• kernel: eBPF 32-bit source register truncation on div/mod (CVE-2021-3600)
• kernel: DoS in rb_per_cpu_empty() (CVE-2021-3679)
• kernel: Mounting overlayfs inside an unprivileged user namespace can reveal files (CVE-2021-3732)
• kernel: heap overflow in __cgroup_bpf_run_filter_getsockopt() (CVE-2021-20194)
• kernel: Race condition in sctp_destroy_sock list_del (CVE-2021-23133)
• kernel: fuse: stall on CPU can occur because a retry loop continually finds the same bad inode (CVE-2021-28950)
• kernel: System crash in intel_pmu_drain_pebs_nhm in arch/x86/events/intel/ds.c (CVE-2021-28971)
• kernel: protection can be bypassed to leak content of kernel memory (CVE-2021-29155)
• kernel: improper input validation in tipc_nl_retrieve_key function in net/tipc/node.c (CVE-2021-29646)
• kernel: lack a full memory barrier may lead to DoS (CVE-2021-29650)
• kernel: local escalation of privileges in handling of eBPF programs (CVE-2021-31440)
• kernel: protection of stack pointer against speculative pointer arithmetic can be bypassed to leak content of kernel memory (CVE-2021-31829)
• kernel: out-of-bounds reads and writes due to enforcing incorrect limits for pointer arithmetic operations by BPF verifier (CVE-2021-33200)
• kernel: reassembling encrypted fragments with non-consecutive packet numbers (CVE-2020-26146)
• kernel: reassembling mixed encrypted/plaintext fragments (CVE-2020-26147)
• kernel: the copy-on-write implementation can grant unintended write access because of a race condition in a THP mapcount check (CVE-2020-29368)
• kernel: flowtable list del corruption with kernel BUG at lib/list_debug.c:50 (CVE-2021-3635)
• kernel: NULL pointer dereference in llsec_key_alloc() in net/mac802154/llsec.c (CVE-2021-3659)
• kernel: setsockopt System Call Untrusted Pointer Dereference Information Disclosure (CVE-2021-20239)
• kernel: out of bounds array access in drivers/md/dm-ioctl.c (CVE-2021-31916)

It was discovered that the Marvell WiFi-Ex device driver in the Linux kernel did not properly validate ad-hoc SSIDs. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-36158)

Ryota Shiga discovered that the sockopt BPF hooks in the Linux kernel could allow a user space program to probe for valid kernel addresses. A local attacker could use this to ease exploitation of another kernel vulnerability. (CVE-2021-20239)

It was discovered that the priority inheritance futex implementation in the Linux kernel contained a race condition, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-3347)

吴异 discovered that the NFS implementation in the Linux kernel did not properly prevent access outside of an NFS export that is a subdirectory of a file system. An attacker could possibly use this to bypass NFS access restrictions. (CVE-2021-3178)

Ryota Shiga discovered that the sockopt BPF hooks in the Linux kernel could allow a user space program to probe for valid kernel addresses. A local attacker could use this to ease exploitation of another kernel vulnerability. (CVE-2021-20239)

It was discovered that the BPF verifier in the Linux kernel did not properly handle signed add32 and sub integer overflows. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-20268)

It was discovered that the priority inheritance futex implementation in the Linux kernel contained a race condition, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-3347)

It was discovered that the network block device (nbd) driver in the Linux kernel contained a use-after-free vulnerability during device setup. A local attacker with access to the nbd device could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-3348)

吴异 discovered that the NFS implementation in the Linux kernel did not properly prevent access outside of an NFS export that is a subdirectory of a file system. An attacker could possibly use this to bypass NFS access restrictions. (CVE-2021-3178)