Linux Kernel up to 6.1.22/6.2.7 kprobe_events p:copy_to_user arg2 null pointer dereference

Summaryinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.1.22/6.2.7. Impacted is the function p:copy_to_user of the file /sys/kernel/tracing/kprobe_events. Performing a manipulation of the argument arg2 results in null pointer dereference. This vulnerability is reported as CVE-2023-53093. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.22/6.2.7. It has been classified as critical. This affects the function p:copy_to_user of the file /sys/kernel/tracing/kprobe_events. The manipulation of the argument arg2 with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: tracing: Do not let histogram values have some modifiers Histogram values can not be strings, stacktraces, graphs, symbols, syscalls, or grouped in buckets or log. Give an error if a value is set to do so. Note, the histogram code was not prepared to handle these modifiers for histograms and caused a bug. Mark Rutland reported: # echo 'p:copy_to_user __arch_copy_to_user n=$arg2' >> /sys/kernel/tracing/kprobe_events # echo 'hist:keys=n:vals=hitcount.buckets=8:sort=hitcount' > /sys/kernel/tracing/events/kprobes/copy_to_user/trigger # cat /sys/kernel/tracing/events/kprobes/copy_to_user/hist [ 143.694628] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 143.695190] Mem abort info: [ 143.695362] ESR = 0x0000000096000004 [ 143.695604] EC = 0x25: DABT (current EL), IL = 32 bits [ 143.695889] SET = 0, FnV = 0 [ 143.696077] EA = 0, S1PTW = 0 [ 143.696302] FSC = 0x04: level 0 translation fault [ 143.702381] Data abort info: [ 143.702614] ISV = 0, ISS = 0x00000004 [ 143.702832] CM = 0, WnR = 0 [ 143.703087] user pgtable: 4k pages, 48-bit VAs, pgdp=00000000448f9000 [ 143.703407] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 [ 143.704137] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP [ 143.704714] Modules linked in: [ 143.705273] CPU: 0 PID: 133 Comm: cat Not tainted 6.2.0-00003-g6fc512c10a7c #3 [ 143.706138] Hardware name: linux,dummy-virt (DT) [ 143.706723] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 143.707120] pc : hist_field_name.part.0+0x14/0x140 [ 143.707504] lr : hist_field_name.part.0+0x104/0x140 [ 143.707774] sp : ffff800008333a30 [ 143.707952] x29: ffff800008333a30 x28: 0000000000000001 x27: 0000000000400cc0 [ 143.708429] x26: ffffd7a653b20260 x25: 0000000000000000 x24: ffff10d303ee5800 [ 143.708776] x23: ffffd7a6539b27b0 x22: ffff10d303fb8c00 x21: 0000000000000001 [ 143.709127] x20: ffff10d303ec2000 x19: 0000000000000000 x18: 0000000000000000 [ 143.709478] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 143.709824] x14: 0000000000000000 x13: 203a6f666e692072 x12: 6567676972742023 [ 143.710179] x11: 0a230a6d6172676f x10: 000000000000002c x9 : ffffd7a6521e018c [ 143.710584] x8 : 000000000000002c x7 : 7f7f7f7f7f7f7f7f x6 : 000000000000002c [ 143.710915] x5 : ffff10d303b0103e x4 : ffffd7a653b20261 x3 : 000000000000003d [ 143.711239] x2 : 0000000000020001 x1 : 0000000000000001 x0 : 0000000000000000 [ 143.711746] Call trace: [ 143.712115] hist_field_name.part.0+0x14/0x140 [ 143.712642] hist_field_name.part.0+0x104/0x140 [ 143.712925] hist_field_print+0x28/0x140 [ 143.713125] event_hist_trigger_print+0x174/0x4d0 [ 143.713348] hist_show+0xf8/0x980 [ 143.713521] seq_read_iter+0x1bc/0x4b0 [ 143.713711] seq_read+0x8c/0xc4 [ 143.713876] vfs_read+0xc8/0x2a4 [ 143.714043] ksys_read+0x70/0xfc [ 143.714218] __arm64_sys_read+0x24/0x30 [ 143.714400] invoke_syscall+0x50/0x120 [ 143.714587] el0_svc_common.constprop.0+0x4c/0x100 [ 143.714807] do_el0_svc+0x44/0xd0 [ 143.714970] el0_svc+0x2c/0x84 [ 143.715134] el0t_64_sync_handler+0xbc/0x140 [ 143.715334] el0t_64_sync+0x190/0x194 [ 143.715742] Code: a9bd7bfd 910003fd a90153f3 aa0003f3 (f9400000) [ 143.716510] ---[ end trace 0000000000000000 ]--- Segmentation fault

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2023-53093 since 05/02/2025. The exploitability is told to be difficult. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 241778 (Amazon Linux 2023 : bpftool, kernel, kernel-devel (ALAS2023-2025-1054)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.23 or 6.2.8 eliminates this vulnerability. Applying the patch 39cd75f2f3a43c0e2f95749eb6dd6420c553f87d/2fc0ee435c9264cdb7c5e872f76cd9bb97640227/e0213434fe3e4a0d118923dc98d31e7ff1cd9e45 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (241778). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3
• 6.1.4
• 6.1.5
• 6.1.6
• 6.1.7
• 6.1.8
• 6.1.9
• 6.1.10
• 6.1.11
• 6.1.12
• 6.1.13
• 6.1.14
• 6.1.15
• 6.1.16
• 6.1.17
• 6.1.18
• 6.1.19
• 6.1.20
• 6.1.21
• 6.1.22
• 6.2.0
• 6.2.1
• 6.2.2
• 6.2.3
• 6.2.4
• 6.2.5
• 6.2.6
• 6.2.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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