In the Linux kernel, the following vulnerability has been resolved:
ARM: 9410/1: vfp: Use asm volatile in fmrx/fmxr macros
Floating point instructions in userspace can crash some arm kernels
built with clang/LLD 17.0.6:
BUG: unsupported FP instruction in kernel mode
FPEXC == 0xc0000780
Internal error: Oops - undefined instruction: 0 [#1] ARM
CPU: 0 PID: 196 Comm: vfp-reproducer Not tainted 6.10.0 #1
Hardware name: BCM2835
PC is at vfp_support_entry+0xc8/0x2cc
LR is at do_undefinstr+0xa8/0x250
pc : [<c0101d50>] lr : [<c010a80c>] psr: a0000013
sp : dc8d1f68 ip : 60000013 fp : bedea19c
r10: ec532b17 r9 : 00000010 r8 : 0044766c
r7 : c0000780 r6 : ec532b17 r5 : c1c13800 r4 : dc8d1fb0
r3 : c10072c4 r2 : c0101c88 r1 : ec532b17 r0 : 0044766c
Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
Control: 00c5387d Table: 0251c008 DAC: 00000051
Register r0 information: non-paged memory
Register r1 information: vmalloc memory
Register r2 information: non-slab/vmalloc memory
Register r3 information: non-slab/vmalloc memory
Register r4 information: 2-page vmalloc region
Register r5 information: slab kmalloc-cg-2k
Register r6 information: vmalloc memory
Register r7 information: non-slab/vmalloc memory
Register r8 information: non-paged memory
Register r9 information: zero-size pointer
Register r10 information: vmalloc memory
Register r11 information: non-paged memory
Register r12 information: non-paged memory
Process vfp-reproducer (pid: 196, stack limit = 0x61aaaf8b)
Stack: (0xdc8d1f68 to 0xdc8d2000)
1f60: 0000081f b6f69300 0000000f c10073f4 c10072c4 dc8d1fb0
1f80: ec532b17 0c532b17 0044766c b6f9ccd8 00000000 c010a80c 00447670 60000010
1fa0: ffffffff c1c13800 00c5387d c0100f10 b6f68af8 00448fc0 00000000 bedea188
1fc0: bedea314 00000001 00448ebc b6f9d000 00447608 b6f9ccd8 00000000 bedea19c
1fe0: bede9198 bedea188 b6e1061c 0044766c 60000010 ffffffff 00000000 00000000
Call trace:
[<c0101d50>] (vfp_support_entry) from [<c010a80c>] (do_undefinstr+0xa8/0x250)
[<c010a80c>] (do_undefinstr) from [<c0100f10>] (__und_usr+0x70/0x80)
Exception stack(0xdc8d1fb0 to 0xdc8d1ff8)
1fa0: b6f68af8 00448fc0 00000000 bedea188
1fc0: bedea314 00000001 00448ebc b6f9d000 00447608 b6f9ccd8 00000000 bedea19c
1fe0: bede9198 bedea188 b6e1061c 0044766c 60000010 ffffffff
Code: 0a000061 e3877202 e594003c e3a09010 (eef16a10)
---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception in interrupt
---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---
This is a minimal userspace reproducer on a Raspberry Pi Zero W:
#include <stdio.h>
#include <math.h>
int main(void)
{
double v = 1.0;
printf("%fn", NAN + *(volatile double *)&v);
return 0;
}
Another way to consistently trigger the oops is:
calvin@raspberry-pi-zero-w ~$ python -c "import json"
The bug reproduces only when the kernel is built with DYNAMIC_DEBUG=n,
because the pr_debug() calls act as barriers even when not activated.
This is the output from the same kernel source built with the same
compiler and DYNAMIC_DEBUG=y, where the userspace reproducer works as
expected:
VFP: bounce: trigger ec532b17 fpexc c0000780
VFP: emulate: INST=0xee377b06 SCR=0x00000000
VFP: bounce: trigger eef1fa10 fpexc c0000780
VFP: emulate: INST=0xeeb40b40 SCR=0x00000000
VFP: raising exceptions 30000000
calvin@raspberry-pi-zero-w ~$ ./vfp-reproducer
nan
Crudely grepping for vmsr/vmrs instructions in the otherwise nearly
idential text for vfp_support_entry() makes the problem obvious:
vmlinux.llvm.good [0xc0101cb8] <+48>: vmrs r7, fpexc
vmlinux.llvm.good [0xc0101cd8] <+80>: vmsr fpexc, r0
vmlinux.llvm.good [0xc0101d20
---truncated---
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Linux |
|
Configuration 1 [-]
|
No data.
References
History
Thu, 13 Feb 2025 00:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-667 |
Thu, 24 Oct 2024 15:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | NVD-CWE-noinfo | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
Tue, 22 Oct 2024 01:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Mon, 21 Oct 2024 13:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Mon, 21 Oct 2024 12:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: ARM: 9410/1: vfp: Use asm volatile in fmrx/fmxr macros Floating point instructions in userspace can crash some arm kernels built with clang/LLD 17.0.6: BUG: unsupported FP instruction in kernel mode FPEXC == 0xc0000780 Internal error: Oops - undefined instruction: 0 [#1] ARM CPU: 0 PID: 196 Comm: vfp-reproducer Not tainted 6.10.0 #1 Hardware name: BCM2835 PC is at vfp_support_entry+0xc8/0x2cc LR is at do_undefinstr+0xa8/0x250 pc : [<c0101d50>] lr : [<c010a80c>] psr: a0000013 sp : dc8d1f68 ip : 60000013 fp : bedea19c r10: ec532b17 r9 : 00000010 r8 : 0044766c r7 : c0000780 r6 : ec532b17 r5 : c1c13800 r4 : dc8d1fb0 r3 : c10072c4 r2 : c0101c88 r1 : ec532b17 r0 : 0044766c Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 00c5387d Table: 0251c008 DAC: 00000051 Register r0 information: non-paged memory Register r1 information: vmalloc memory Register r2 information: non-slab/vmalloc memory Register r3 information: non-slab/vmalloc memory Register r4 information: 2-page vmalloc region Register r5 information: slab kmalloc-cg-2k Register r6 information: vmalloc memory Register r7 information: non-slab/vmalloc memory Register r8 information: non-paged memory Register r9 information: zero-size pointer Register r10 information: vmalloc memory Register r11 information: non-paged memory Register r12 information: non-paged memory Process vfp-reproducer (pid: 196, stack limit = 0x61aaaf8b) Stack: (0xdc8d1f68 to 0xdc8d2000) 1f60: 0000081f b6f69300 0000000f c10073f4 c10072c4 dc8d1fb0 1f80: ec532b17 0c532b17 0044766c b6f9ccd8 00000000 c010a80c 00447670 60000010 1fa0: ffffffff c1c13800 00c5387d c0100f10 b6f68af8 00448fc0 00000000 bedea188 1fc0: bedea314 00000001 00448ebc b6f9d000 00447608 b6f9ccd8 00000000 bedea19c 1fe0: bede9198 bedea188 b6e1061c 0044766c 60000010 ffffffff 00000000 00000000 Call trace: [<c0101d50>] (vfp_support_entry) from [<c010a80c>] (do_undefinstr+0xa8/0x250) [<c010a80c>] (do_undefinstr) from [<c0100f10>] (__und_usr+0x70/0x80) Exception stack(0xdc8d1fb0 to 0xdc8d1ff8) 1fa0: b6f68af8 00448fc0 00000000 bedea188 1fc0: bedea314 00000001 00448ebc b6f9d000 00447608 b6f9ccd8 00000000 bedea19c 1fe0: bede9198 bedea188 b6e1061c 0044766c 60000010 ffffffff Code: 0a000061 e3877202 e594003c e3a09010 (eef16a10) ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Fatal exception in interrupt ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- This is a minimal userspace reproducer on a Raspberry Pi Zero W: #include <stdio.h> #include <math.h> int main(void) { double v = 1.0; printf("%fn", NAN + *(volatile double *)&v); return 0; } Another way to consistently trigger the oops is: calvin@raspberry-pi-zero-w ~$ python -c "import json" The bug reproduces only when the kernel is built with DYNAMIC_DEBUG=n, because the pr_debug() calls act as barriers even when not activated. This is the output from the same kernel source built with the same compiler and DYNAMIC_DEBUG=y, where the userspace reproducer works as expected: VFP: bounce: trigger ec532b17 fpexc c0000780 VFP: emulate: INST=0xee377b06 SCR=0x00000000 VFP: bounce: trigger eef1fa10 fpexc c0000780 VFP: emulate: INST=0xeeb40b40 SCR=0x00000000 VFP: raising exceptions 30000000 calvin@raspberry-pi-zero-w ~$ ./vfp-reproducer nan Crudely grepping for vmsr/vmrs instructions in the otherwise nearly idential text for vfp_support_entry() makes the problem obvious: vmlinux.llvm.good [0xc0101cb8] <+48>: vmrs r7, fpexc vmlinux.llvm.good [0xc0101cd8] <+80>: vmsr fpexc, r0 vmlinux.llvm.good [0xc0101d20 ---truncated--- | |
| Title | ARM: 9410/1: vfp: Use asm volatile in fmrx/fmxr macros | |
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-10-21T11:53:47.434Z
Updated: 2025-05-04T09:38:10.072Z
Reserved: 2024-09-30T16:00:12.949Z
Link: CVE-2024-47716
Vulnrichment
Updated: 2024-10-21T13:02:40.761Z
NVD
Status : Analyzed
Published: 2024-10-21T12:15:07.943
Modified: 2024-10-24T14:34:17.863
Link: CVE-2024-47716
Redhat