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CVE-2022-50579
arm64: ftrace: fix module PLTs with mcount
Description

In the Linux kernel, the following vulnerability has been resolved: arm64: ftrace: fix module PLTs with mcount Li Huafei reports that mcount-based ftrace with module PLTs was broken by commit: a6253579977e4c6f ("arm64: ftrace: consistently handle PLTs.") When a module PLTs are used and a module is loaded sufficiently far away from the kernel, we'll create PLTs for any branches which are out-of-range. These are separate from the special ftrace trampoline PLTs, which the module PLT code doesn't directly manipulate. When mcount is in use this is a problem, as each mcount callsite in a module will be initialized to point to a module PLT, but since commit a6253579977e4c6f ftrace_make_nop() will assume that the callsite has been initialized to point to the special ftrace trampoline PLT, and ftrace_find_callable_addr() rejects other cases. This means that when ftrace tries to initialize a callsite via ftrace_make_nop(), the call to ftrace_find_callable_addr() will find that the `_mcount` stub is out-of-range and is not handled by the ftrace PLT, resulting in a splat: | ftrace_test: loading out-of-tree module taints kernel. | ftrace: no module PLT for _mcount | ------------[ ftrace bug ]------------ | ftrace failed to modify | [<ffff800029180014>] 0xffff800029180014 | actual: 44:00:00:94 | Initializing ftrace call sites | ftrace record flags: 2000000 | (0) | expected tramp: ffff80000802eb3c | ------------[ cut here ]------------ | WARNING: CPU: 3 PID: 157 at kernel/trace/ftrace.c:2120 ftrace_bug+0x94/0x270 | Modules linked in: | CPU: 3 PID: 157 Comm: insmod Tainted: G O 6.0.0-rc6-00151-gcd722513a189-dirty #22 | Hardware name: linux,dummy-virt (DT) | pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : ftrace_bug+0x94/0x270 | lr : ftrace_bug+0x21c/0x270 | sp : ffff80000b2bbaf0 | x29: ffff80000b2bbaf0 x28: 0000000000000000 x27: ffff0000c4d38000 | x26: 0000000000000001 x25: ffff800009d7e000 x24: ffff0000c4d86e00 | x23: 0000000002000000 x22: ffff80000a62b000 x21: ffff8000098ebea8 | x20: ffff0000c4d38000 x19: ffff80000aa24158 x18: ffffffffffffffff | x17: 0000000000000000 x16: 0a0d2d2d2d2d2d2d x15: ffff800009aa9118 | x14: 0000000000000000 x13: 6333626532303830 x12: 3030303866666666 | x11: 203a706d61727420 x10: 6465746365707865 x9 : 3362653230383030 | x8 : c0000000ffffefff x7 : 0000000000017fe8 x6 : 000000000000bff4 | x5 : 0000000000057fa8 x4 : 0000000000000000 x3 : 0000000000000001 | x2 : ad2cb14bb5438900 x1 : 0000000000000000 x0 : 0000000000000022 | Call trace: | ftrace_bug+0x94/0x270 | ftrace_process_locs+0x308/0x430 | ftrace_module_init+0x44/0x60 | load_module+0x15b4/0x1ce8 | __do_sys_init_module+0x1ec/0x238 | __arm64_sys_init_module+0x24/0x30 | invoke_syscall+0x54/0x118 | el0_svc_common.constprop.4+0x84/0x100 | do_el0_svc+0x3c/0xd0 | el0_svc+0x1c/0x50 | el0t_64_sync_handler+0x90/0xb8 | el0t_64_sync+0x15c/0x160 | ---[ end trace 0000000000000000 ]--- | ---------test_init----------- Fix this by reverting to the old behaviour of ignoring the old instruction when initialising an mcount callsite in a module, which was the behaviour prior to commit a6253579977e4c6f.

INFO

Published Date :

Oct. 22, 2025, 2:15 p.m.

Last Modified :

Oct. 22, 2025, 9:12 p.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products

The following products are affected by CVE-2022-50579 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
Solution
Update the Linux kernel to resolve issues with module PLTs and mcount-based ftrace.
  • Update the Linux kernel.
  • Revert commit a6253579977e4c6f.
  • Ignore old instruction on mcount callsite init.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2022-50579.

URL Resource
https://git.kernel.org/stable/c/0f77b6b2ba70d7c9d69ef39694e283ded9f8b5f2
https://git.kernel.org/stable/c/657de36c72f57fa172a66b06f826b3f5bc56f42e
https://git.kernel.org/stable/c/6c93b683cedaef745884cb9d554d02ed6266b897
https://git.kernel.org/stable/c/8cfb08575c6d4585f1ce0deeb189e5c824776b04
https://git.kernel.org/stable/c/985432303cf7d4804fb2c2fdfbf0466a796d68c3
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2022-50579 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2022-50579 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2022-50579 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2022-50579 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Oct. 22, 2025

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: arm64: ftrace: fix module PLTs with mcount Li Huafei reports that mcount-based ftrace with module PLTs was broken by commit: a6253579977e4c6f ("arm64: ftrace: consistently handle PLTs.") When a module PLTs are used and a module is loaded sufficiently far away from the kernel, we'll create PLTs for any branches which are out-of-range. These are separate from the special ftrace trampoline PLTs, which the module PLT code doesn't directly manipulate. When mcount is in use this is a problem, as each mcount callsite in a module will be initialized to point to a module PLT, but since commit a6253579977e4c6f ftrace_make_nop() will assume that the callsite has been initialized to point to the special ftrace trampoline PLT, and ftrace_find_callable_addr() rejects other cases. This means that when ftrace tries to initialize a callsite via ftrace_make_nop(), the call to ftrace_find_callable_addr() will find that the `_mcount` stub is out-of-range and is not handled by the ftrace PLT, resulting in a splat: | ftrace_test: loading out-of-tree module taints kernel. | ftrace: no module PLT for _mcount | ------------[ ftrace bug ]------------ | ftrace failed to modify | [<ffff800029180014>] 0xffff800029180014 | actual: 44:00:00:94 | Initializing ftrace call sites | ftrace record flags: 2000000 | (0) | expected tramp: ffff80000802eb3c | ------------[ cut here ]------------ | WARNING: CPU: 3 PID: 157 at kernel/trace/ftrace.c:2120 ftrace_bug+0x94/0x270 | Modules linked in: | CPU: 3 PID: 157 Comm: insmod Tainted: G O 6.0.0-rc6-00151-gcd722513a189-dirty #22 | Hardware name: linux,dummy-virt (DT) | pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : ftrace_bug+0x94/0x270 | lr : ftrace_bug+0x21c/0x270 | sp : ffff80000b2bbaf0 | x29: ffff80000b2bbaf0 x28: 0000000000000000 x27: ffff0000c4d38000 | x26: 0000000000000001 x25: ffff800009d7e000 x24: ffff0000c4d86e00 | x23: 0000000002000000 x22: ffff80000a62b000 x21: ffff8000098ebea8 | x20: ffff0000c4d38000 x19: ffff80000aa24158 x18: ffffffffffffffff | x17: 0000000000000000 x16: 0a0d2d2d2d2d2d2d x15: ffff800009aa9118 | x14: 0000000000000000 x13: 6333626532303830 x12: 3030303866666666 | x11: 203a706d61727420 x10: 6465746365707865 x9 : 3362653230383030 | x8 : c0000000ffffefff x7 : 0000000000017fe8 x6 : 000000000000bff4 | x5 : 0000000000057fa8 x4 : 0000000000000000 x3 : 0000000000000001 | x2 : ad2cb14bb5438900 x1 : 0000000000000000 x0 : 0000000000000022 | Call trace: | ftrace_bug+0x94/0x270 | ftrace_process_locs+0x308/0x430 | ftrace_module_init+0x44/0x60 | load_module+0x15b4/0x1ce8 | __do_sys_init_module+0x1ec/0x238 | __arm64_sys_init_module+0x24/0x30 | invoke_syscall+0x54/0x118 | el0_svc_common.constprop.4+0x84/0x100 | do_el0_svc+0x3c/0xd0 | el0_svc+0x1c/0x50 | el0t_64_sync_handler+0x90/0xb8 | el0t_64_sync+0x15c/0x160 | ---[ end trace 0000000000000000 ]--- | ---------test_init----------- Fix this by reverting to the old behaviour of ignoring the old instruction when initialising an mcount callsite in a module, which was the behaviour prior to commit a6253579977e4c6f.
    Added Reference https://git.kernel.org/stable/c/0f77b6b2ba70d7c9d69ef39694e283ded9f8b5f2
    Added Reference https://git.kernel.org/stable/c/657de36c72f57fa172a66b06f826b3f5bc56f42e
    Added Reference https://git.kernel.org/stable/c/6c93b683cedaef745884cb9d554d02ed6266b897
    Added Reference https://git.kernel.org/stable/c/8cfb08575c6d4585f1ce0deeb189e5c824776b04
    Added Reference https://git.kernel.org/stable/c/985432303cf7d4804fb2c2fdfbf0466a796d68c3
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
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