In the Linux kernel, the following vulnerability has been resolved: BPF: Fix potential bad pointer dereference in bpf_sys_bpf() The bpf_sys_bpf() helper function allows an eBPF program to load another eBPF program from within the kernel. In this case the argument union bpf_attr pointer (as well as the insns and license pointers inside) is a kernel address instead of a userspace address (which is the case of a usual bpf() syscall). To make the memory copying process in the syscall work in both cases, bpfptr_t was introduced to wrap around the pointer and distinguish its origin. Specifically, when copying memory contents from a bpfptr_t, a copy_from_user() is performed in case of a userspace address and a memcpy() is performed for a kernel address. This can lead to problems because the in-kernel pointer is never checked for validity. The problem happens when an eBPF syscall program tries to call bpf_sys_bpf() to load a program but provides a bad insns pointer -- say 0xdeadbeef -- in the bpf_attr union. The helper calls __sys_bpf() which would then call bpf_prog_load() to load the program. bpf_prog_load() is responsible for copying the eBPF instructions to the newly allocated memory for the program; it creates a kernel bpfptr_t for insns and invokes copy_from_bpfptr(). Internally, all bpfptr_t operations are backed by the corresponding sockptr_t operations, which performs direct memcpy() on kernel pointers for copy_from/strncpy_from operations. Therefore, the code is always happy to dereference the bad pointer to trigger a un-handle-able page fault and in turn an oops. However, this is not supposed to happen because at that point the eBPF program is already verified and should not cause a memory error. Sample KASAN trace: [ 25.685056][ T228] ================================================================== [ 25.685680][ T228] BUG: KASAN: user-memory-access in copy_from_bpfptr+0x21/0x30 [ 25.686210][ T228] Read of size 80 at addr 00000000deadbeef by task poc/228 [ 25.686732][ T228] [ 25.686893][ T228] CPU: 3 PID: 228 Comm: poc Not tainted 5.19.0-rc7 #7 [ 25.687375][ T228] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS d55cb5a 04/01/2014 [ 25.687991][ T228] Call Trace: [ 25.688223][ T228] <TASK> [ 25.688429][ T228] dump_stack_lvl+0x73/0x9e [ 25.688747][ T228] print_report+0xea/0x200 [ 25.689061][ T228] ? copy_from_bpfptr+0x21/0x30 [ 25.689401][ T228] ? _printk+0x54/0x6e [ 25.689693][ T228] ? _raw_spin_lock_irqsave+0x70/0xd0 [ 25.690071][ T228] ? copy_from_bpfptr+0x21/0x30 [ 25.690412][ T228] kasan_report+0xb5/0xe0 [ 25.690716][ T228] ? copy_from_bpfptr+0x21/0x30 [ 25.691059][ T228] kasan_check_range+0x2bd/0x2e0 [ 25.691405][ T228] ? copy_from_bpfptr+0x21/0x30 [ 25.691734][ T228] memcpy+0x25/0x60 [ 25.692000][ T228] copy_from_bpfptr+0x21/0x30 [ 25.692328][ T228] bpf_prog_load+0x604/0x9e0 [ 25.692653][ T228] ? cap_capable+0xb4/0xe0 [ 25.692956][ T228] ? security_capable+0x4f/0x70 [ 25.693324][ T228] __sys_bpf+0x3af/0x580 [ 25.693635][ T228] bpf_sys_bpf+0x45/0x240 [ 25.693937][ T228] bpf_prog_f0ec79a5a3caca46_bpf_func1+0xa2/0xbd [ 25.694394][ T228] bpf_prog_run_pin_on_cpu+0x2f/0xb0 [ 25.694756][ T228] bpf_prog_test_run_syscall+0x146/0x1c0 [ 25.695144][ T228] bpf_prog_test_run+0x172/0x190 [ 25.695487][ T228] __sys_bpf+0x2c5/0x580 [ 25.695776][ T228] __x64_sys_bpf+0x3a/0x50 [ 25.696084][ T228] do_syscall_64+0x60/0x90 [ 25.696393][ T228] ? fpregs_assert_state_consistent+0x50/0x60 [ 25.696815][ T228] ? exit_to_user_mode_prepare+0x36/0xa0 [ 25.697202][ T228] ? syscall_exit_to_user_mode+0x20/0x40 [ 25.697586][ T228] ? do_syscall_64+0x6e/0x90 [ 25.697899][ T228] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 25.698312][ T228] RIP: 0033:0x7f6d543fb759 [ 25.698624][ T228] Code: 08 5b 89 e8 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d ---truncated---

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - In the Linux kernel, the following vulnerability has been resolved: BPF: Fix potential bad pointer     dereference in bpf_sys_bpf() The bpf_sys_bpf() helper function allows an eBPF program to load another eBPF     program from within the kernel. In this case the argument union bpf_attr pointer (as well as the insns and     license pointers inside) is a kernel address instead of a userspace address (which is the case of a usual     bpf() syscall). To make the memory copying process in the syscall work in both cases, bpfptr_t was     introduced to wrap around the pointer and distinguish its origin. Specifically, when copying memory     contents from a bpfptr_t, a copy_from_user() is performed in case of a userspace address and a memcpy() is     performed for a kernel address. This can lead to problems because the in-kernel pointer is never checked     for validity. The problem happens when an eBPF syscall program tries to call bpf_sys_bpf() to load a     program but provides a bad insns pointer -- say 0xdeadbeef -- in the bpf_attr union. The helper calls
    __sys_bpf() which would then call bpf_prog_load() to load the program. bpf_prog_load() is responsible for     copying the eBPF instructions to the newly allocated memory for the program; it creates a kernel bpfptr_t     for insns and invokes copy_from_bpfptr(). Internally, all bpfptr_t operations are backed by the     corresponding sockptr_t operations, which performs direct memcpy() on kernel pointers for     copy_from/strncpy_from operations. Therefore, the code is always happy to dereference the bad pointer to     trigger a un-handle-able page fault and in turn an oops. However, this is not supposed to happen because     at that point the eBPF program is already verified and should not cause a memory error. Sample KASAN     trace: [ 25.685056][ T228] ================================================================== [     25.685680][ T228] BUG: KASAN: user-memory-access in copy_from_bpfptr+0x21/0x30 [ 25.686210][ T228] Read of     size 80 at addr 00000000deadbeef by task poc/228 [ 25.686732][ T228] [ 25.686893][ T228] CPU: 3 PID: 228     Comm: poc Not tainted 5.19.0-rc7 #7 [ 25.687375][ T228] Hardware name: QEMU Standard PC (i440FX + PIIX,     1996), BIOS d55cb5a 04/01/2014 [ 25.687991][ T228] Call Trace: [ 25.688223][ T228] <TASK> [ 25.688429][     T228] dump_stack_lvl+0x73/0x9e [ 25.688747][ T228] print_report+0xea/0x200 [ 25.689061][ T228] ?     copy_from_bpfptr+0x21/0x30 [ 25.689401][ T228] ? _printk+0x54/0x6e [ 25.689693][ T228] ?
    _raw_spin_lock_irqsave+0x70/0xd0 [ 25.690071][ T228] ? copy_from_bpfptr+0x21/0x30 [ 25.690412][ T228]     kasan_report+0xb5/0xe0 [ 25.690716][ T228] ? copy_from_bpfptr+0x21/0x30 [ 25.691059][ T228]     kasan_check_range+0x2bd/0x2e0 [ 25.691405][ T228] ? copy_from_bpfptr+0x21/0x30 [ 25.691734][ T228]     memcpy+0x25/0x60 [ 25.692000][ T228] copy_from_bpfptr+0x21/0x30 [ 25.692328][ T228]     bpf_prog_load+0x604/0x9e0 [ 25.692653][ T228] ? cap_capable+0xb4/0xe0 [ 25.692956][ T228] ?     security_capable+0x4f/0x70 [ 25.693324][ T228] __sys_bpf+0x3af/0x580 [ 25.693635][ T228]     bpf_sys_bpf+0x45/0x240 [ 25.693937][ T228] bpf_prog_f0ec79a5a3caca46_bpf_func1+0xa2/0xbd [ 25.694394][     T228] bpf_prog_run_pin_on_cpu+0x2f/0xb0 [ 25.694756][ T228] bpf_prog_test_run_syscall+0x146/0x1c0 [     25.695144][ T228] bpf_prog_test_run+0x172/0x190 [ 25.695487][ T228] __sys_bpf+0x2c5/0x580 [ 25.695776][     T228] __x64_sys_bpf+0x3a/0x50 [ 25.696084][ T228] do_syscall_64+0x60/0x90 [ 25.696393][ T228] ?     fpregs_assert_state_consistent+0x50/0x60 [ 25.696815][ T228] ? exit_to_user_mode_prepare+0x36/0xa0 [     25.697202][ T228] ? syscall_exit_to_user_mode+0x20/0x40 [ 25.697586][ T228] ? do_syscall_64+0x6e/0x90 [     25.697899][ T228] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 25.698312][ T228] RIP: 0033:0x7f6d543fb759 [     25.698624][ T228] Code: 08 5b 89 e8 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 48 89 f8 48 89 f7 48 89 d6 48     89 ca 4d ---truncated--- (CVE-2022-50069)

Note that Nessus relies on the presence of the package as reported by the vendor.

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2023:2458 advisory.

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

    Security Fix(es):

    * use-after-free in l2cap_connect and l2cap_le_connect_req in net/bluetooth/l2cap_core.c (CVE-2022-42896)

    * net/ulp: use-after-free in listening ULP sockets (CVE-2023-0461)

    * cpu: AMD CPUs may transiently execute beyond unconditional direct branch (CVE-2021-26341)

    * malicious data for FBIOPUT_VSCREENINFO ioctl may cause OOB write memory (CVE-2021-33655)

    * possible race condition in drivers/tty/tty_buffers.c (CVE-2022-1462)

    * KVM: NULL pointer dereference in kvm_mmu_invpcid_gva (CVE-2022-1789)

    * use-after-free in free_pipe_info() could lead to privilege escalation (CVE-2022-1882)

    * KVM: nVMX: missing IBPB when exiting from nested guest can lead to Spectre v2 attacks (CVE-2022-2196)

    * netfilter: nf_conntrack_irc message handling issue (CVE-2022-2663)

    * race condition in xfrm_probe_algs can lead to OOB read/write (CVE-2022-3028)

    * out-of-bounds read in fib_nh_match of the file net/ipv4/fib_semantics.c (CVE-2022-3435)

    * race condition in hugetlb_no_page() in mm/hugetlb.c (CVE-2022-3522)

    * memory leak in ipv6_renew_options() (CVE-2022-3524)

    * data races around icsk->icsk_af_ops in do_ipv6_setsockopt (CVE-2022-3566)

    * data races around sk->sk_prot (CVE-2022-3567)

    * memory leak in l2cap_recv_acldata of the file net/bluetooth/l2cap_core.c (CVE-2022-3619)

    * denial of service in follow_page_pte in mm/gup.c due to poisoned pte entry (CVE-2022-3623)

    * use-after-free after failed devlink reload in devlink_param_get (CVE-2022-3625)

    * USB-accessible buffer overflow in brcmfmac (CVE-2022-3628)

    * use after free flaw in l2cap_conn_del in net/bluetooth/l2cap_core.c (CVE-2022-3640)

    * Double-free in split_2MB_gtt_entry when function intel_gvt_dma_map_guest_page failed (CVE-2022-3707)

    * mptcp: NULL pointer dereference in subflow traversal at disconnect time (CVE-2022-4128)

    * l2tp: missing lock when clearing sk_user_data can lead to NULL pointer dereference (CVE-2022-4129)

    * igmp: use-after-free in ip_check_mc_rcu when opening and closing inet sockets (CVE-2022-20141)

    * lockdown bypass using IMA (CVE-2022-21505)

    * double free in usb_8dev_start_xmit in drivers/net/can/usb/usb_8dev.c (CVE-2022-28388)

    * network backend may cause Linux netfront to use freed SKBs (XSA-405) (CVE-2022-33743)

    * unmap_mapping_range() race with munmap() on VM_PFNMAP mappings leads to stale TLB entry (CVE-2022-39188)

    * TLB flush operations are mishandled in certain KVM_VCPU_PREEMPTED leading to guest malfunctioning     (CVE-2022-39189)

    * u8 overflow problem in cfg80211_update_notlisted_nontrans() (CVE-2022-41674)

    * use-after-free related to leaf anon_vma double reuse (CVE-2022-42703)

    * use-after-free in bss_ref_get in net/wireless/scan.c (CVE-2022-42720)

    * BSS list corruption in cfg80211_add_nontrans_list in net/wireless/scan.c (CVE-2022-42721)

    * Denial of service in beacon protection for P2P-device (CVE-2022-42722)

    * memory corruption in usbmon driver (CVE-2022-43750)

    * NULL pointer dereference in traffic control subsystem (CVE-2022-47929)

    * NULL pointer dereference in rawv6_push_pending_frames (CVE-2023-0394)

    * use-after-free due to race condition in qdisc_graft() (CVE-2023-0590)

    * use-after-free caused by invalid pointer hostname in fs/cifs/connect.c (CVE-2023-1195)

    * denial of service in tipc_conn_close (CVE-2023-1382)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

    Additional Changes:

    For detailed information on changes in this release, see the Red Hat Enterprise Linux 9.2 Release Notes     linked from the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2022:7683 advisory.

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

    Security Fix(es):

    * off-path attacker may inject data or terminate victim's TCP session (CVE-2020-36516)

    * race condition in VT_RESIZEX ioctl when vc_cons[i].d is already NULL leading to NULL pointer dereference     (CVE-2020-36558)

    * use-after-free vulnerability in function sco_sock_sendmsg() (CVE-2021-3640)

    * memory leak for large arguments in video_usercopy function in drivers/media/v4l2-core/v4l2-ioctl.c     (CVE-2021-30002)

    * smb2_ioctl_query_info NULL Pointer Dereference (CVE-2022-0168)

    * NULL pointer dereference in udf_expand_file_adinicbdue() during writeback (CVE-2022-0617)

    * swiotlb information leak with DMA_FROM_DEVICE (CVE-2022-0854)

    * uninitialized registers on stack in nft_do_chain can cause kernel pointer leakage to UM (CVE-2022-1016)

    * race condition in snd_pcm_hw_free leading to use-after-free (CVE-2022-1048)

    * use-after-free in tc_new_tfilter() in net/sched/cls_api.c (CVE-2022-1055)

    * use-after-free and memory errors in ext4 when mounting and operating on a corrupted image     (CVE-2022-1184)

    * NULL pointer dereference in x86_emulate_insn may lead to DoS (CVE-2022-1852)

    * buffer overflow in nft_set_desc_concat_parse() (CVE-2022-2078)

    * nf_tables cross-table potential use-after-free may lead to local privilege escalation (CVE-2022-2586)

    * openvswitch: integer underflow leads to out-of-bounds write in reserve_sfa_size() (CVE-2022-2639)

    * use-after-free when psi trigger is destroyed while being polled (CVE-2022-2938)

    * net/packet: slab-out-of-bounds access in packet_recvmsg() (CVE-2022-20368)

    * possible to use the debugger to write zero into a location of choice (CVE-2022-21499)

    * Spectre-BHB (CVE-2022-23960)

    * Post-barrier Return Stack Buffer Predictions (CVE-2022-26373)

    * memory leak in drivers/hid/hid-elo.c (CVE-2022-27950)

    * double free in ems_usb_start_xmit in drivers/net/can/usb/ems_usb.c (CVE-2022-28390)

    * use after free in SUNRPC subsystem (CVE-2022-28893)

    * use-after-free due to improper update of reference count in net/sched/cls_u32.c (CVE-2022-29581)

    * DoS in nfqnl_mangle in net/netfilter/nfnetlink_queue.c (CVE-2022-36946)

    * nfs_atomic_open() returns uninitialized data instead of ENOTDIR (CVE-2022-24448)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

    Additional Changes:

    For detailed information on changes in this release, see the Red Hat Enterprise Linux 8.7 Release Notes     linked from the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
243912	Linux Distros Unpatched Vulnerability : CVE-2022-50069	Nessus	Misc.	medium
175477	RHEL 9 : kernel (RHSA-2023:2458)	Nessus	Red Hat Local Security Checks	high
167155	RHEL 8 : kernel (RHSA-2022:7683)	Nessus	Red Hat Local Security Checks	high
166118	Amazon Linux 2 : kernel, --advisory ALAS2KERNEL-5.15-2022-008 (ALASKERNEL-5.15-2022-008)	Nessus	Amazon Linux Local Security Checks	high

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