Amazon Linux 2 : kernel (ALASKERNEL-5.15-2024-036)

high Nessus Plugin ID 190021

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of kernel installed on the remote host is prior to 5.15.148-97.158. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2KERNEL-5.15-2024-036 advisory.

- Transmit requests in Xen's virtual network protocol can consist of multiple parts. While not really useful, except for the initial part any of them may be of zero length, i.e. carry no data at all. Besides a certain initial portion of the to be transferred data, these parts are directly translated into what Linux calls SKB fragments. Such converted request parts can, when for a particular SKB they are all of length zero, lead to a de-reference of NULL in core networking code. (CVE-2023-46838)

- In the Linux kernel, the following vulnerability has been resolved: uio: Fix use-after-free in uio_open core-1 core-2 ------------------------------------------------------- uio_unregister_device uio_open idev = idr_find() device_unregister(&idev->dev) put_device(&idev->dev) uio_device_release get_device(&idev->dev) kfree(idev) uio_free_minor(minor) uio_release put_device(&idev->dev) kfree(idev)
------------------------------------------------------- In the core-1 uio_unregister_device(), the device_unregister will kfree idev when the idev->dev kobject ref is 1. But after core-1 device_unregister, put_device and before doing kfree, the core-2 may get_device. Then: 1. After core-1 kfree idev, the core-2 will do use-after-free for idev. 2. When core-2 do uio_release and put_device, the idev will be double freed. To address this issue, we can get idev atomic & inc idev reference with minor_lock.
(CVE-2023-52439)

- In the Linux kernel, the following vulnerability has been resolved: bpf: fix check for attempt to corrupt spilled pointer When register is spilled onto a stack as a 1/2/4-byte register, we set slot_type[BPF_REG_SIZE - 1] (plus potentially few more below it, depending on actual spill size). So to check if some stack slot has spilled register we need to consult slot_type[7], not slot_type[0]. To avoid the need to remember and double-check this in the future, just use is_spilled_reg() helper.
(CVE-2023-52462)

- In the Linux kernel, the following vulnerability has been resolved: efivarfs: force RO when remounting if SetVariable is not supported If SetVariable at runtime is not supported by the firmware we never assign a callback for that function. At the same time mount the efivarfs as RO so no one can call that. However, we never check the permission flags when someone remounts the filesystem as RW. As a result this leads to a crash looking like this: $ mount -o remount,rw /sys/firmware/efi/efivars $ efi-updatevar -f PK.auth PK [ 303.279166] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 303.280482] Mem abort info: [ 303.280854] ESR = 0x0000000086000004 [ 303.281338] EC = 0x21: IABT (current EL), IL = 32 bits [ 303.282016] SET = 0, FnV = 0 [ 303.282414] EA = 0, S1PTW = 0 [ 303.282821] FSC = 0x04:
level 0 translation fault [ 303.283771] user pgtable: 4k pages, 48-bit VAs, pgdp=000000004258c000 [ 303.284913] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 [ 303.286076] Internal error:
Oops: 0000000086000004 [#1] PREEMPT SMP [ 303.286936] Modules linked in: qrtr tpm_tis tpm_tis_core crct10dif_ce arm_smccc_trng rng_core drm fuse ip_tables x_tables ipv6 [ 303.288586] CPU: 1 PID: 755 Comm:
efi-updatevar Not tainted 6.3.0-rc1-00108-gc7d0c4695c68 #1 [ 303.289748] Hardware name: Unknown Unknown Product/Unknown Product, BIOS 2023.04-00627-g88336918701d 04/01/2023 [ 303.291150] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 303.292123] pc : 0x0 [ 303.292443] lr :
efivar_set_variable_locked+0x74/0xec [ 303.293156] sp : ffff800008673c10 [ 303.293619] x29:
ffff800008673c10 x28: ffff0000037e8000 x27: 0000000000000000 [ 303.294592] x26: 0000000000000800 x25:
ffff000002467400 x24: 0000000000000027 [ 303.295572] x23: ffffd49ea9832000 x22: ffff0000020c9800 x21:
ffff000002467000 [ 303.296566] x20: 0000000000000001 x19: 00000000000007fc x18: 0000000000000000 [ 303.297531] x17: 0000000000000000 x16: 0000000000000000 x15: 0000aaaac807ab54 [ 303.298495] x14:
ed37489f673633c0 x13: 71c45c606de13f80 x12: 47464259e219acf4 [ 303.299453] x11: ffff000002af7b01 x10:
0000000000000003 x9 : 0000000000000002 [ 303.300431] x8 : 0000000000000010 x7 : ffffd49ea8973230 x6 :
0000000000a85201 [ 303.301412] x5 : 0000000000000000 x4 : ffff0000020c9800 x3 : 00000000000007fc [ 303.302370] x2 : 0000000000000027 x1 : ffff000002467400 x0 : ffff000002467000 [ 303.303341] Call trace: [ 303.303679] 0x0 [ 303.303938] efivar_entry_set_get_size+0x98/0x16c [ 303.304585] efivarfs_file_write+0xd0/0x1a4 [ 303.305148] vfs_write+0xc4/0x2e4 [ 303.305601] ksys_write+0x70/0x104 [ 303.306073] __arm64_sys_write+0x1c/0x28 [ 303.306622] invoke_syscall+0x48/0x114 [ 303.307156] el0_svc_common.constprop.0+0x44/0xec [ 303.307803] do_el0_svc+0x38/0x98 [ 303.308268] el0_svc+0x2c/0x84 [ 303.308702] el0t_64_sync_handler+0xf4/0x120 [ 303.309293] el0t_64_sync+0x190/0x194 [ 303.309794] Code:
???????? ???????? ???????? ???????? (????????) [ 303.310612] ---[ end trace 0000000000000000 ]--- Fix this by adding a .reconfigure() function to the fs operations which we can use to check the requested flags and deny anything that's not RO if the firmware doesn't implement SetVariable at runtime. (CVE-2023-52463)

- In the Linux kernel, the following vulnerability has been resolved: mfd: syscon: Fix null pointer dereference in of_syscon_register() kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure. (CVE-2023-52467)

- An out-of-bounds access vulnerability involving netfilter was reported and fixed as: f1082dd31fe4 (netfilter: nf_tables: Reject tables of unsupported family); While creating a new netfilter table, lack of a safeguard against invalid nf_tables family (pf) values within `nf_tables_newtable` function enables an attacker to achieve out-of-bounds access. (CVE-2023-6040)

- A Null pointer dereference problem was found in ida_free in lib/idr.c in the Linux Kernel. This issue may allow an attacker using this library to cause a denial of service problem due to a missing check at a function return. (CVE-2023-6915)

- An out-of-bounds memory read flaw was found in receive_encrypted_standard in fs/smb/client/smb2ops.c in the SMB Client sub-component in the Linux Kernel. This issue occurs due to integer underflow on the memcpy length, leading to a denial of service. (CVE-2024-0565)

- An out-of-bounds memory write flaw was found in the Linux kernel's Transport Layer Security functionality in how a user calls a function splice with a ktls socket as the destination. This flaw allows a local user to crash or potentially escalate their privileges on the system. (CVE-2024-0646)

- A use-after-free vulnerability in the Linux kernel's netfilter: nf_tables component can be exploited to achieve local privilege escalation. The nft_setelem_catchall_deactivate() function checks whether the catch-all set element is active in the current generation instead of the next generation before freeing it, but only flags it inactive in the next generation, making it possible to free the element multiple times, leading to a double free vulnerability. We recommend upgrading past commit b1db244ffd041a49ecc9618e8feb6b5c1afcdaa7. (CVE-2024-1085)

- In the Linux kernel, the following vulnerability has been resolved: bpf: Fix re-attachment branch in bpf_tracing_prog_attach The following case can cause a crash due to missing attach_btf: 1) load rawtp program 2) load fentry program with rawtp as target_fd 3) create tracing link for fentry program with target_fd = 0 4) repeat 3 In the end we have: - prog->aux->dst_trampoline == NULL - tgt_prog == NULL (because we did not provide target_fd to link_create) - prog->aux->attach_btf == NULL (the program was loaded with attach_prog_fd=X) - the program was loaded for tgt_prog but we have no way to find out which one BUG: kernel NULL pointer dereference, address: 0000000000000058 Call Trace: <TASK> ? __die+0x20/0x70 ? page_fault_oops+0x15b/0x430 ? fixup_exception+0x22/0x330 ? exc_page_fault+0x6f/0x170 ? asm_exc_page_fault+0x22/0x30 ? bpf_tracing_prog_attach+0x279/0x560 ? btf_obj_id+0x5/0x10 bpf_tracing_prog_attach+0x439/0x560 __sys_bpf+0x1cf4/0x2de0 __x64_sys_bpf+0x1c/0x30 do_syscall_64+0x41/0xf0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 Return -EINVAL in this situation.
(CVE-2024-26591)

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

Solution

Run 'yum update kernel' to update your system.

See Also

https://alas.aws.amazon.com/AL2/ALASKERNEL-5.15-2024-036.html

https://alas.aws.amazon.com/faqs.html

https://alas.aws.amazon.com/cve/html/CVE-2023-6040.html

https://alas.aws.amazon.com/cve/html/CVE-2023-6915.html

https://alas.aws.amazon.com/cve/html/CVE-2023-46838.html

https://alas.aws.amazon.com/cve/html/CVE-2023-52439.html

https://alas.aws.amazon.com/cve/html/CVE-2023-52462.html

https://alas.aws.amazon.com/cve/html/CVE-2023-52463.html

https://alas.aws.amazon.com/cve/html/CVE-2023-52467.html

https://alas.aws.amazon.com/cve/html/CVE-2024-0565.html

https://alas.aws.amazon.com/cve/html/CVE-2024-0646.html

https://alas.aws.amazon.com/cve/html/CVE-2024-1085.html

https://alas.aws.amazon.com/cve/html/CVE-2024-26591.html

Plugin Details

Severity: High

ID: 190021

File Name: al2_ALASKERNEL-5_15-2024-036.nasl

Version: 1.4

Type: local

Agent: unix

Published: 2/6/2024

Updated: 4/25/2024

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: High

Base Score: 7.7

Temporal Score: 5.7

Vector: CVSS2#AV:A/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2024-0565

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS Score Source: CVE-2024-1085

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:bpftool, p-cpe:/a:amazon:linux:bpftool-debuginfo, p-cpe:/a:amazon:linux:kernel, p-cpe:/a:amazon:linux:kernel-debuginfo, p-cpe:/a:amazon:linux:kernel-debuginfo-common-aarch64, p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64, p-cpe:/a:amazon:linux:kernel-devel, p-cpe:/a:amazon:linux:kernel-headers, p-cpe:/a:amazon:linux:kernel-livepatch-5.15.148-97.158, p-cpe:/a:amazon:linux:kernel-tools, p-cpe:/a:amazon:linux:kernel-tools-debuginfo, p-cpe:/a:amazon:linux:kernel-tools-devel, p-cpe:/a:amazon:linux:perf, p-cpe:/a:amazon:linux:perf-debuginfo, p-cpe:/a:amazon:linux:python-perf, p-cpe:/a:amazon:linux:python-perf-debuginfo, cpe:/o:amazon:linux:2

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 2/1/2024

Vulnerability Publication Date: 1/12/2024

Reference Information

CVE: CVE-2023-46838, CVE-2023-52439, CVE-2023-52462, CVE-2023-52463, CVE-2023-52467, CVE-2023-6040, CVE-2023-6915, CVE-2024-0565, CVE-2024-0646, CVE-2024-1085, CVE-2024-26591