CVE-2021-20265

A flaw was found in the way memory resources were freed in the unix_stream_recvmsg function in the Linux kernel when a signal was pending. This flaw allows an unprivileged local user to crash the system by exhausting available memory. The highest threat from this vulnerability is to system availability.

• ELSCVE-666: CVE-2021-34693: can: bcm: fix infoleak in struct bcm_msg_head
• ELSCVE-705: CVE-2021-38160: virtio_console: Assure used length from device is limited
• ELSCVE-769: CVE-2014-4508: x86_32, entry: Do syscall exit work on badsys (CVE-2014-4508)
• ELSCVE-844: CVE-2021-3573: Bluetooth: use correct lock to prevent UAF of hdev object
• ELSCVE-503: CVE-2021-32399: bluetooth: eliminate the potential race condition when removing the HCI controller
• ELSCVE-451: CVE-2021-37159: hso: fix a use after free condition
• ELSCVE-387: CVE-2021-38205: net: xilinx_emaclite: Do not print real IOMEM pointer
• ELSCVE-547: CVE-2021-3178: nfsd4: readdirplus shouldn't return parent of export
• ELSCVE-547: nfsd: fix compose_entry_fh() failure exits
• ELSCVE-547: nfsd: make local functions static
• ELSCVE-682: CVE-2021-20265: af_unix: fix struct pid memory leak
• ELSCVE-531: CVE-2021-20292: drm/ttm/nouveau: don't call tt destroy callback on alloc failure.
• ELSCVE-543: CVE-2021-28972: PCI: rpadlpar: Fix potential drc_name corruption in store functions
• ELSCVE-575: CVE-2021-3612: Input: joydev - prevent use of not validated data in JSIOCSBTNMAP ioctl
• ELSCVE-575: Input: joydev - prevent potential read overflow in ioctl
• ELSCVE-575: Input: joydev - fix possible ERR_PTR() dereferencing
• ELSCVE-575: Input: joydev - use memdup_user() to duplicate memory from user-space

• ELSCVE-666: CVE-2021-34693: can: bcm: fix infoleak in struct bcm_msg_head
• ELSCVE-705: CVE-2021-38160: virtio_console: Assure used length from device is limited
• ELSCVE-769: CVE-2014-4508: x86_32, entry: Do syscall exit work on badsys (CVE-2014-4508)
• ELSCVE-844: CVE-2021-3573: Bluetooth: use correct lock to prevent UAF of hdev object
• ELSCVE-503: CVE-2021-32399: bluetooth: eliminate the potential race condition when removing the HCI controller
• ELSCVE-451: CVE-2021-37159: hso: fix a use after free condition
• ELSCVE-387: CVE-2021-38205: net: xilinx_emaclite: Do not print real IOMEM pointer
• ELSCVE-547: CVE-2021-3178: nfsd4: readdirplus shouldn't return parent of export
• ELSCVE-547: nfsd: fix compose_entry_fh() failure exits
• ELSCVE-547: nfsd: make local functions static
• ELSCVE-682: CVE-2021-20265: af_unix: fix struct pid memory leak
• ELSCVE-531: CVE-2021-20292: drm/ttm/nouveau: don't call tt destroy callback on alloc failure.
• ELSCVE-543: CVE-2021-28972: PCI: rpadlpar: Fix potential drc_name corruption in store functions
• ELSCVE-575: CVE-2021-3612: Input: joydev - prevent use of not validated data in JSIOCSBTNMAP ioctl
• ELSCVE-575: Input: joydev - prevent potential read overflow in ioctl
• ELSCVE-575: Input: joydev - fix possible ERR_PTR() dereferencing
• ELSCVE-575: Input: joydev - use memdup_user() to duplicate memory from user-space

The SUSE Linux Enterprise 11 SP4 LTSS kernel was updated to receive various security and bugfixes.

The following security bugs were fixed:

• CVE-2021-37159: hso_free_net_device in drivers/net/usb/hso.c called unregister_netdev without checking for the NETREG_REGISTERED state, leading to a use-after-free and a double free (bnc#1188601).
• CVE-2021-3772: Fixed sctp vtag check in sctp_sf_ootb (bsc#1190351).
• CVE-2021-3655: Missing size validations on inbound SCTP packets may have allowed the kernel to read uninitialized memory (bnc#1188563 bnc#1192267).
• CVE-2014-7841: The sctp_process_param function in net/sctp/sm_make_chunk.c in the SCTP implementation, when ASCONF is used, allowed remote attackers to cause a denial of service (NULL pointer dereference and system crash) via a malformed INIT chunk (bnc#904899 bnc#905100).
• CVE-2021-20265: A flaw was found in the way memory resources were freed in the unix_stream_recvmsg function when a signal was pending. This flaw allowed an unprivileged local user to crash the system by exhausting available memory. The highest threat from this vulnerability is to system availability (bnc#1183089).
• CVE-2021-42739: The firewire subsystem had a buffer overflow related to drivers/media/firewire/firedtv-avc.c and drivers/media/firewire/firedtv-ci.c, because avc_ca_pmt mishandled bounds checking (bnc#1184673 bnc#1192036).
• CVE-2021-33033: The Linux kernel has a use-after-free in cipso_v4_genopt 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 (bnc#1186109 bnc#1188876).
• CVE-2021-43389: There was an array-index-out-of-bounds flaw in the detach_capi_ctr function in drivers/isdn/capi/kcapi.c (bnc#1191958).
• CVE-2021-42008: The decode_data function in drivers/net/hamradio/6pack.c had a slab out-of-bounds write. Input from a process that has the CAP_NET_ADMIN capability can lead to root access (bnc#1191315).
• CVE-2021-38160: Data corruption or loss could be triggered by an untrusted device that supplies a buf->len value exceeding the buffer size in drivers/char/virtio_console.c (bsc#1190117)
• CVE-2021-3640: Fixed a Use-After-Free vulnerability in function sco_sock_sendmsg() in the bluetooth stack (bsc#1188172).
• CVE-2021-38198: arch/x86/kvm/mmu/paging_tmpl.h incorrectly computed the access permissions of a shadow page, leading to a missing guest protection page fault (bnc#1189262).
• CVE-2021-3653: A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the 'int_ctl' field, this issue could allow a malicious L1 to enable AVIC support (Advanced Virtual Interrupt Controller) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape. (bnc#1189399).
• CVE-2021-3679: A lack of CPU resource in the Linux kernel tracing module functionality was found in the way user uses trace ring buffer in a specific way. Only privileged local users (with CAP_SYS_ADMIN capability) could use this flaw to starve the resources causing denial of service (bnc#1189057).
• CVE-2021-3609: A potential local privilege escalation in the CAN BCM networking protocol was fixed (bsc#1187215).
• CVE-2020-36385: drivers/infiniband/core/ucma.c has a use-after-free because the ctx is reached via the ctx_list in some ucma_migrate_id situations where ucma_close is called, aka CID-f5449e74802c (bnc#1187050).

The following non-security bugs were fixed:

• sctp: check asoc peer.asconf_capable before processing asconf (bsc#1190351).
• sctp: fully initialize v4 addr in some functions (bsc#1188563).
• sctp: simplify addr copy (bsc#1188563).

The SUSE Linux Enterprise 12 SP2 LTSS kernel was updated to receive various security and bugfixes.

The following security bugs were fixed:

• Unprivileged BPF has been disabled by default to reduce attack surface as too many security issues have happened in the past (jsc#SLE-22573)

  You can reenable via systemctl setting /proc/sys/kernel/unprivileged_bpf_disabled to 0. (kernel.unprivileged_bpf_disabled = 0)

• CVE-2017-5753: Systems with microprocessors utilizing speculative execution and branch prediction may have allowed unauthorized disclosure of information to an attacker with local user access via a side-channel analysis (bnc#1068032). Additional spectrev1 fixes were added to the eBPF code.

• CVE-2018-13405: The inode_init_owner function in fs/inode.c allowed local users to create files with an unintended group ownership, in a scenario where a directory is SGID to a certain group and is writable by a user who is not a member of that group. Here, the non-member can trigger creation of a plain file whose group ownership is that group. The intended behavior was that the non-member can trigger creation of a directory (but not a plain file) whose group ownership is that group. The non-member can escalate privileges by making the plain file executable and SGID (bnc#1087082 bnc#1100416 bnc#1129735).

• CVE-2018-16882: A use-after-free issue was found in the way the KVM hypervisor processed posted interrupts when nested(=1) virtualization is enabled. In nested_get_vmcs12_pages(), in case of an error while processing posted interrupt address, it unmaps the 'pi_desc_page' without resetting 'pi_desc' descriptor address, which is later used in pi_test_and_clear_on(). A guest user/process could use this flaw to crash the host kernel resulting in DoS or potentially gain privileged access to a system. Kernel versions and are vulnerable (bnc#1119934).

• CVE-2020-0429: In l2tp_session_delete and related functions of l2tp_core.c, there is possible memory corruption due to a use after free. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation (bnc#1176724).

• CVE-2020-12655: An issue was discovered in xfs_agf_verify in fs/xfs/libxfs/xfs_alloc.c in the Linux kernel Attackers may trigger a sync of excessive duration via an XFS v5 image with crafted metadata, aka CID-d0c7feaf8767 (bnc#1171217).

• CVE-2020-14305: An out-of-bounds memory write flaw was found in how the Linux kernel’s Voice Over IP H.323 connection tracking functionality handled connections on ipv6 port 1720. This flaw allowed an unauthenticated remote user to crash the system, causing a denial of service. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability (bnc#1173346).

• CVE-2020-3702: Specifically timed and handcrafted traffic can cause internal errors in a WLAN device that lead to improper layer 2 Wi-Fi encryption with a consequent possibility of information disclosure over the air for a discrete set of traffic (bnc#1191193).

• CVE-2021-20265: A flaw was found in the way memory resources were freed in the unix_stream_recvmsg function in the Linux kernel when a signal was pending. This flaw allowed an unprivileged local user to crash the system by exhausting available memory. The highest threat from this vulnerability is to system availability (bnc#1183089).

• CVE-2021-31916: An out-of-bounds (OOB) memory write flaw was found in list_devices in drivers/md/dm-ioctl.c in the Multi-device driver module in the Linux kernel A bound check failure allowed an attacker with special user (CAP_SYS_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 (bnc#1192781).

• CVE-2021-33033: The Linux kernel has a use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c because the CIPSO and CALIPSO…

The SUSE Linux Enterprise 12 SP3 LTSS kernel was updated to receive various security and bugfixes.

The following security bugs were fixed:

• Unprivileged BPF has been disabled by default to reduce attack surface as too many security issues have happened in the past (jsc#SLE-22573)

  You can reenable via systemctl setting /proc/sys/kernel/unprivileged_bpf_disabled to 0. (kernel.unprivileged_bpf_disabled = 0)

• CVE-2021-31916: An out-of-bounds (OOB) memory write flaw was found in list_devices in drivers/md/dm-ioctl.c in the Multi-device driver module in the Linux kernel A bound check failure allowed an attacker with special user (CAP_SYS_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 (bnc#1192781).

• CVE-2021-20322: Make the ipv4 and ipv6 ICMP exception caches less predictive to avoid information leaks about UDP ports in use. (bsc#1191790)

• CVE-2021-34981: Fixed file refcounting in cmtp when cmtp_attach_device fails (bsc#1191961).

• CVE-2020-12655: An issue was discovered in xfs_agf_verify in fs/xfs/libxfs/xfs_alloc.c. Attackers may trigger a sync of excessive duration via an XFS v5 image with crafted metadata, aka CID-d0c7feaf8767 (bnc#1171217).

• CVE-2021-43389: There was an array-index-out-of-bounds flaw in the detach_capi_ctr function in drivers/isdn/capi/kcapi.c (bnc#1191958).

• CVE-2021-37159: hso_free_net_device in drivers/net/usb/hso.c called unregister_netdev without checking for the NETREG_REGISTERED state, leading to a use-after-free and a double free (bnc#1188601).

• CVE-2021-34556: An unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because the protection mechanism neglects the possibility of uninitialized memory locations on the BPF stack (bnc#1188983).

• CVE-2021-35477: An unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because a certain preempting store operation did not necessarily occur before a store operation that has an attacker-controlled value (bnc#1188985).

• CVE-2017-17862: kernel/bpf/verifier.c in the Linux kernel ignores unreachable code, even though it would still be processed by JIT compilers. This behavior, also considered an improper branch-pruning logic issue, could possibly be used by local users for denial of service (bnc#1073928).

• CVE-2017-17864: kernel/bpf/verifier.c in the Linux kernel mishandled states_equal comparisons between the pointer data type and the UNKNOWN_VALUE data type, which allowed local users to obtain potentially sensitive address information, aka a 'pointer leak (bnc#1073928).

• CVE-2021-20265: A flaw was found in the way memory resources were freed in the unix_stream_recvmsg function in the Linux kernel when a signal was pending. This flaw allowed an unprivileged local user to crash the system by exhausting available memory. The highest threat from this vulnerability is to system availability (bnc#1183089).

• CVE-2021-3772: Fixed sctp vtag check in sctp_sf_ootb (bsc#1190351).

• CVE-2021-3655: Missing size validations on inbound SCTP packets may have allowed the kernel to read uninitialized memory (bnc#1188563).

• CVE-2018-13405: The inode_init_owner function in fs/inode.c in the Linux kernel allowed local users to create files with an unintended group ownership, in a scenario where a directory is SGID to a certain group and is writable by a user who is not a member of that group. Here, the non-member can trigger creation of a plain file whose group ownership is that group. The intended behavior was that the non-member can trigger creation of a directory (but not a plain file) whose group ownership is that group. The non-member can escalate privileges by making the plain file executable and SGID (bnc#1100416 bnc#1129735).

• CVE-2021-3760: Fixed a use-after-free…