CVE-2022-50579
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2022-50579
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-50579.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2022-50579
- Downstream
- Published
- 2025-10-22T13:23:32.242Z
- Modified
- 2025-12-04T23:37:32.983542Z
- Summary
- arm64: ftrace: fix module PLTs with mcount
- Details
-
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 ftracemakenop() will assume that the callsite has been initialized to point to the special ftrace trampoline PLT, and ftracefindcallable_addr() rejects other cases.
This means that when ftrace tries to initialize a callsite via ftracemakenop(), the call to ftracefindcallable_addr() will find that the
_mcountstub is out-of-range and is not handled by the ftrace PLT, resulting in a splat:| ftracetest: 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 ftracebug+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 : ftracebug+0x94/0x270 | lr : ftracebug+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: | ftracebug+0x94/0x270 | ftraceprocesslocs+0x308/0x430 | ftracemoduleinit+0x44/0x60 | loadmodule+0x15b4/0x1ce8 | _dosysinitmodule+0x1ec/0x238 | _arm64sysinitmodule+0x24/0x30 | invokesyscall+0x54/0x118 | el0svccommon.constprop.4+0x84/0x100 | doel0svc+0x3c/0xd0 | el0svc+0x1c/0x50 | el0t64synchandler+0x90/0xb8 | el0t64sync+0x15c/0x160 | ---[ end trace 0000000000000000 ]--- | ---------testinit-----------
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.
- Database specific
{ "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/50xxx/CVE-2022-50579.json", "cna_assigner": "Linux" }- References
-
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- 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
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/50xxx/CVE-2022-50579.json
- https://nvd.nist.gov/vuln/detail/CVE-2022-50579
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedbc28fde90937a920f7714ec4408269cac744f796Fixed657de36c72f57fa172a66b06f826b3f5bc56f42e
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduceddb73aa9466338ec821ed2a0b01721fe4d06876b1Fixed6c93b683cedaef745884cb9d554d02ed6266b897
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduceda6253579977e4c6f7818eeb05bf2bc65678a7187Fixed0f77b6b2ba70d7c9d69ef39694e283ded9f8b5f2Fixed985432303cf7d4804fb2c2fdfbf0466a796d68c3Fixed8cfb08575c6d4585f1ce0deeb189e5c824776b04
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced0 Unknown introduced commit / All previous commits are affectedLast affecteddcecc96ed16f73417de5550f384e348c9d56f279
Affected versions
v2.*
v3.*
v4.*
v5.*
v6.*
Linux / Kernel
Package
- Name
- Kernel