{"id":"DEBIAN-CVE-2024-47716","details":"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 : [\u003cc0101d50\u003e]    lr : [\u003cc010a80c\u003e]    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:     [\u003cc0101d50\u003e] (vfp_support_entry) from [\u003cc010a80c\u003e] (do_undefinstr+0xa8/0x250)     [\u003cc010a80c\u003e] (do_undefinstr) from [\u003cc0100f10\u003e] (__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 \u003cstdio.h\u003e     #include \u003cmath.h\u003e      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] \u003c+48\u003e:  vmrs   r7, fpexc     vmlinux.llvm.good [0xc0101cd8] \u003c+80\u003e:  vmsr   fpexc, r0     vmlinux.llvm.good [0xc0101d20 ---truncated---","modified":"2026-09-15T09:03:11.995315156Z","published":"2024-10-21T12:15:07.943Z","upstream":["CVE-2024-47716"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2024-47716"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.11.2-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2024-47716.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.11.2-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2024-47716.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}