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CVE-2024-36906NVD status: Analyzed

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2024-36906 is a high-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 20ac71bee028ffbae4fc14ed679b23b4d3e95726, ad702338fe423cb1e79745787090317256a98dab, ee0ce7573e5083031960faf602c9db693ab5b477 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.23% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 20ac71bee028ffbae4fc14ed679b23b4d3e95726 or ad702338fe423cb1e79745787090317256a98dab or ee0ce7573e5083031960faf602c9db693ab5b477 or b26f353786d365e658cebc9a9ace88e04fc2325e, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.15.159 or 6.1.91 or 6.6.31 or 6.8.10, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux5615f69bc2097452ecc954f5264d784e158d6801 up to, but not including, 20ac71bee028ffbae4fc14ed679b23b4d3e95726; 5615f69bc2097452ecc954f5264d784e158d6801 up to, but not including, ad702338fe423cb1e79745787090317256a98dab; 5615f69bc2097452ecc954f5264d784e158d6801 up to, but not including, ee0ce7573e5083031960faf602c9db693ab5b477; 5615f69bc2097452ecc954f5264d784e158d6801 up to, but not including, b26f353786d365e658cebc9a9ace88e04fc2325e; 5615f69bc2097452ecc954f5264d784e158d6801 up to, but not including, c4238686f9093b98bd6245a348bcf059cdce23af; 5.1120ac71bee028ffbae4fc14ed679b23b4d3e95726, ad702338fe423cb1e79745787090317256a98dab, ee0ce7573e5083031960faf602c9db693ab5b477, b26f353786d365e658cebc9a9ace88e04fc2325e, c4238686f9093b98bd6245a348bcf059cdce23af
LinuxLinux Kernel5.11 up to, but not including, 5.15.159; 5.16 up to, but not including, 6.1.91; 6.2 up to, but not including, 6.6.31; 6.7 up to, but not including, 6.8.10; 6.95.15.159, 6.1.91, 6.6.31, 6.8.10

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

In the Linux kernel, the following vulnerability has been resolved: ARM: 9381/1: kasan: clear stale stack poison We found below OOB crash: [ 33.452494] ================================================================== [ 33.453513] BUG: KASAN: stack-out-of-bounds in refresh_cpu_vm_stats.constprop.0+0xcc/0x2ec [ 33.454660] Write of size 164 at addr c1d03d30 by task swapper/0/0 [ 33.455515] [ 33.455767] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O 6.1.25-mainline #1 [ 33.456880] Hardware name: Generic DT based system [ 33.457555] unwind_backtrace from show_stack+0x18/0x1c [ 33.458326] show_stack from dump_stack_lvl+0x40/0x4c [ 33.459072] dump_stack_lvl from print_report+0x158/0x4a4 [ 33.459863] print_report from kasan_report+0x9c/0x148 [ 33.460616] kasan_report from kasan_check_range+0x94/0x1a0 [ 33.461424] kasan_check_range from memset+0x20/0x3c [ 33.462157] memset from refresh_cpu_vm_stats.constprop.0+0xcc/0x2ec [ 33.463064] refresh_cpu_vm_stats.constprop.0 from tick_nohz_idle_stop_tick+0x180/0x53c [ 33.464181] tick_nohz_idle_stop_tick from do_idle+0x264/0x354 [ 33.465029] do_idle from cpu_startup_entry+0x20/0x24 [ 33.465769] cpu_startup_entry from rest_init+0xf0/0xf4 [ 33.466528] rest_init from arch_post_acpi_subsys_init+0x0/0x18 [ 33.467397] [ 33.467644] The buggy address belongs to stack of task swapper/0/0 [ 33.468493] and is located at offset 112 in frame: [ 33.469172] refresh_cpu_vm_stats.constprop.0+0x0/0x2ec [ 33.469917] [ 33.470165] This frame has 2 objects: [ 33.470696] [32, 76) 'global_zone_diff' [ 33.470729] [112, 276) 'global_node_diff' [ 33.471294] [ 33.472095] The buggy address belongs to the physical page: [ 33.472862] page:3cd72da8 refcount:1 mapcount:0 mapping:00000000 index:0x0 pfn:0x41d03 [ 33.473944] flags: 0x1000(reserved|zone=0) [ 33.474565] raw: 00001000 ed741470 ed741470 00000000 00000000 00000000 ffffffff 00000001 [ 33.475656] raw: 00000000 [ 33.476050] page dumped because: kasan: bad access detected [ 33.476816] [ 33.477061] Memory state around the buggy address: [ 33.477732] c1d03c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 33.478630] c1d03c80: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00 [ 33.479526] >c1d03d00: 00 04 f2 f2 f2 f2 00 00 00 00 00 00 f1 f1 f1 f1 [ 33.480415] ^ [ 33.481195] c1d03d80: 00 00 00 00 00 00 00 00 00 00 04 f3 f3 f3 f3 f3 [ 33.482088] c1d03e00: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 [ 33.482978] ================================================================== We find the root cause of this OOB is that arm does not clear stale stack poison in the case of cpuidle. This patch refer to arch/arm64/kernel/sleep.S to resolve this issue. From cited commit [1] that explain the problem Functions which the compiler has instrumented for KASAN place poison on the stack shadow upon entry and remove this poison prior to returning. In the case of cpuidle, CPUs exit the kernel a number of levels deep in C code. Any instrumented functions on this critical path will leave portions of the stack shadow poisoned. If CPUs lose context and return to the kernel via a cold path, we restore a prior context saved in __cpu_suspend_enter are forgotten, and we never remove the poison they placed in the stack shadow area by functions calls between this and the actual exit of the kernel. Thus, (depending on stackframe layout) subsequent calls to instrumented functions may hit this stale poison, resulting in (spurious) KASAN splats to the console. To avoid this, clear any stale poison from the idle thread for a CPU prior to bringing a CPU online. From cited commit [2] Extend to check for CONFIG_KASAN_STACK [1] commit 0d97e6d8024c ("arm64: kasan: clear stale stack poison") [2] commit d56a9ef84bd0 ("kasan, arm64: unpoison stack only with CONFIG_KASAN_STACK")

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Out-of-bounds Write vulnerabilities (CWE-787)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

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