CVE-2025-37991

parisc: Fix double SIGFPE crash

Published May 20, 2025 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed

Description

In the Linux kernel, the following vulnerability has been resolved:

parisc: Fix double SIGFPE crash

Camm noticed that on parisc a SIGFPE exception will crash an application with
a second SIGFPE in the signal handler. Dave analyzed it, and it happens
because glibc uses a double-word floating-point store to atomically update
function descriptors. As a result of lazy binding, we hit a floating-point
store in fpe_func almost immediately.

When the T bit is set, an assist exception trap occurs when when the
co-processor encounters *any* floating-point instruction except for a double
store of register %fr0. The latter cancels all pending traps. Let's fix this
by clearing the Trap (T) bit in the FP status register before returning to the
signal handler in userspace.

The issue can be reproduced with this test program:

root@parisc:~# cat fpe.c

static void fpe_func(int sig, siginfo_t *i, void *v) {
sigset_t set;
sigemptyset(&set);
sigaddset(&set, SIGFPE);
sigprocmask(SIG_UNBLOCK, &set, NULL);
printf("GOT signal %d with si_code %ld\n", sig, i->si_code);
}

int main() {
struct sigaction action = {
.sa_sigaction = fpe_func,
.sa_flags = SA_RESTART|SA_SIGINFO };
sigaction(SIGFPE, &action, 0);
feenableexcept(FE_OVERFLOW);
return printf("%lf\n",1.7976931348623158E308*1.7976931348623158E308);
}

root@parisc:~# gcc fpe.c -lm
root@parisc:~# ./a.out
Floating point exception

root@parisc:~# strace -f ./a.out
execve("./a.out", ["./a.out"], 0xf9ac7034 /* 20 vars */) = 0
getrlimit(RLIMIT_STACK, {rlim_cur=8192*1024, rlim_max=RLIM_INFINITY}) = 0
...
rt_sigaction(SIGFPE, {sa_handler=0x1110a, sa_mask=[], sa_flags=SA_RESTART|SA_SIGINFO}, NULL, 8) = 0
--- SIGFPE {si_signo=SIGFPE, si_code=FPE_FLTOVF, si_addr=0x1078f} ---
--- SIGFPE {si_signo=SIGFPE, si_code=FPE_FLTOVF, si_addr=0xf8f21237} ---
+++ killed by SIGFPE +++
Floating point exception

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< 2a1aff3616b3b57aa4a5f8a7762cce1e82493fe6
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< 757ba4d17b868482837c566cfefca59e2296c608
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< ec4584495868bd465fe60a3f771915c0e7ce7951
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< 6c639af49e9e5615a8395981eaf5943fb40acd6f
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< 6a098c51d18ec99485668da44294565c43dbc106
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< cf21e890f56b7d0038ddaf25224e4f4c69ecd143
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< df3592e493d7f29bae4ffde9a9325de50ddf962e
`1da177e4c3f41524e886b7f1b8a0c1fc7321cac2`	affected	< de3629baf5a33af1919dec7136d643b0662e85ef

Linux

affected

Version	Status	Constraints
`2.6.12`	affected	—
`0`	unaffected	< 2.6.12
`5.4.294`	unaffected	≤ 5.4.*
`5.10.238`	unaffected	≤ 5.10.*
`5.15.182`	unaffected	≤ 5.15.*
`6.1.138`	unaffected	≤ 6.1.*
`6.6.90`	unaffected	≤ 6.6.*
`6.12.28`	unaffected	≤ 6.12.*
`6.14.6`	unaffected	≤ 6.14.*
`6.15`	unaffected	≤ *

Configuration 1 [-]

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel:6.15:rc1::::::
	cpe:2.3:o:linux:linux_kernel:6.15:rc2::::::
	cpe:2.3:o:linux:linux_kernel:6.15:rc3::::::
	cpe:2.3:o:linux:linux_kernel:6.15:rc4::::::

Configuration 2 [-]

cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

No data.

Vendor	Product	Versions
Linux	Linux Kernel	—

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

Source	ID	Title
Debian DLA	DLA-4271-1	linux-6.1 security update
Debian DSA	DSA-5925-1	linux security update
EUVD	EUVD-2025-15863	In the Linux kernel, the following vulnerability has been resolved: parisc: Fix double SIGFPE crash Camm noticed that on parisc a SIGFPE exception will crash an application with a second SIGFPE in the signal handler. Dave analyzed it, and it happens because glibc uses a double-word floating-point store to atomically update function descriptors. As a result of lazy binding, we hit a floating-point store in fpe_func almost immediately. When the T bit is set, an assist exception trap occurs when when the co-processor encounters any floating-point instruction except for a double store of register %fr0. The latter cancels all pending traps. Let's fix this by clearing the Trap (T) bit in the FP status register before returning to the signal handler in userspace. The issue can be reproduced with this test program: root@parisc:~# cat fpe.c static void fpe_func(int sig, siginfo_t i, void v) { sigset_t set; sigemptyset(&set); sigaddset(&set, SIGFPE); sigprocmask(SIG_UNBLOCK, &set, NULL); printf("GOT signal %d with si_code %ld\n", sig, i->si_code); } int main() { struct sigaction action = { .sa_sigaction = fpe_func, .sa_flags = SA_RESTART\|SA_SIGINFO }; sigaction(SIGFPE, &action, 0); feenableexcept(FE_OVERFLOW); return printf("%lf\n",1.7976931348623158E3081.7976931348623158E308); } root@parisc:~# gcc fpe.c -lm root@parisc:~# ./a.out Floating point exception root@parisc:~# strace -f ./a.out execve("./a.out", ["./a.out"], 0xf9ac7034 / 20 vars /) = 0 getrlimit(RLIMIT_STACK, {rlim_cur=81921024, rlim_max=RLIM_INFINITY}) = 0 ... rt_sigaction(SIGFPE, {sa_handler=0x1110a, sa_mask=[], sa_flags=SA_RESTART\|SA_SIGINFO}, NULL, 8) = 0 --- SIGFPE {si_signo=SIGFPE, si_code=FPE_FLTOVF, si_addr=0x1078f} --- --- SIGFPE {si_signo=SIGFPE, si_code=FPE_FLTOVF, si_addr=0xf8f21237} --- +++ killed by SIGFPE +++ Floating point exception
Ubuntu USN	USN-7649-1	Linux kernel vulnerabilities
Ubuntu USN	USN-7649-2	Linux kernel (AWS) vulnerabilities
Ubuntu USN	USN-7650-1	Linux kernel (OEM) vulnerabilities
Ubuntu USN	USN-7654-1	Linux kernel vulnerabilities
Ubuntu USN	USN-7654-2	Linux kernel (Real-time) vulnerabilities
Ubuntu USN	USN-7654-3	Linux kernel (FIPS) vulnerabilities
Ubuntu USN	USN-7654-4	Linux kernel (KVM) vulnerabilities
Ubuntu USN	USN-7654-5	Linux kernel (Xilinx ZynqMP) vulnerabilities
Ubuntu USN	USN-7655-1	Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN	USN-7665-1	Linux kernel (Oracle) vulnerabilities
Ubuntu USN	USN-7665-2	Linux kernel (AWS) vulnerabilities
Ubuntu USN	USN-7686-1	Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN	USN-7711-1	Linux kernel (Azure) vulnerabilities
Ubuntu USN	USN-7712-1	Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN	USN-7712-2	Linux kernel (Azure) vulnerabilities
Ubuntu USN	USN-7721-1	Linux kernel (Azure) vulnerabilities
Ubuntu USN	USN-8028-1	Linux kernel vulnerabilities
Ubuntu USN	USN-8028-2	Linux kernel (Real-time) vulnerabilities
Ubuntu USN	USN-8031-1	Linux kernel (GCP) vulnerabilities
Ubuntu USN	USN-8028-3	Linux kernel (Real-time) vulnerabilities
Ubuntu USN	USN-8028-4	Linux kernel (FIPS) vulnerabilities
Ubuntu USN	USN-8028-5	Linux kernel vulnerabilities
Ubuntu USN	USN-8031-2	Linux kernel (GCP FIPS) vulnerabilities
Ubuntu USN	USN-8028-6	Linux kernel (HWE) vulnerabilities
Ubuntu USN	USN-8031-3	Linux kernel vulnerabilities
Ubuntu USN	USN-8052-1	Linux kernel (Low Latency) vulnerabilities
Ubuntu USN	USN-8028-7	Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN	USN-8028-8	Linux kernel (IBM) vulnerabilities
Ubuntu USN	USN-8052-2	Linux kernel (Xilinx) vulnerabilities
Ubuntu USN	USN-8074-1	Linux kernel (Azure) vulnerabilities
Ubuntu USN	USN-8074-2	Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN	USN-8126-1	Linux kernel (Azure) vulnerabilities

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.225% probability within 30 days)

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/stable/c/2a1aff3616b3b57aa4a5f8a7762cce1e82493fe6
https://git.kernel.org/stable/c/6a098c51d18ec99485668da44294565c43dbc106
https://git.kernel.org/stable/c/6c639af49e9e5615a8395981eaf5943fb40acd6f
https://git.kernel.org/stable/c/757ba4d17b868482837c566cfefca59e2296c608
https://git.kernel.org/stable/c/cf21e890f56b7d0038ddaf25224e4f4c69ecd143
https://git.kernel.org/stable/c/de3629baf5a33af1919dec7136d643b0662e85ef
https://git.kernel.org/stable/c/df3592e493d7f29bae4ffde9a9325de50ddf962e
https://git.kernel.org/stable/c/ec4584495868bd465fe60a3f771915c0e7ce7951
https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html
https://lore.kernel.org/linux-cve-announce/2025052000-CVE-2025-37991-c6dc@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2025-37991
https://www.cve.org/CVERecord?id=CVE-2025-37991

History

Dec 16, 2025 8:30 PM First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Scoring metrics updated View changes

Type	Values Removed	Values Added
First Time appeared		Debian Debian debian Linux
Weaknesses		CWE-415
CPEs		cpe:2.3:o:debian:debian_linux:11.0:::::::* cpe:2.3:o:linux:linux_kernel:::::::: cpe:2.3:o:linux:linux_kernel:6.15:rc1:::::: cpe:2.3:o:linux:linux_kernel:6.15:rc2:::::: cpe:2.3:o:linux:linux_kernel:6.15:rc3:::::: cpe:2.3:o:linux:linux_kernel:6.15:rc4::::::
Vendors & Products		Debian Debian debian Linux
Metrics	cvssV3_1 `{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}`	cvssV3_1 `{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}`

Nov 3, 2025 8:30 PM Added references View changes

Type	Values Removed	Values Added
References		https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html

Jul 14, 2025 1:45 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics	epss `{'score': 0.00061}`	epss `{'score': 0.00051}`

Jun 17, 2025 3:00 PM Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
References		https://lore.kernel.org/linux-cve-announce/2025052000-CVE-2025-37991-c6dc@gregkh/T https://nvd.nist.gov/vuln/detail/CVE-2025-37991 https://www.cve.org/CVERecord?id=CVE-2025-37991
Metrics	threat_severity `None`	cvssV3_1 `{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}` threat_severity `Moderate`

Jun 4, 2025 1:00 PM Added references View changes

Type	Values Removed	Values Added
References		https://git.kernel.org/stable/c/2a1aff3616b3b57aa4a5f8a7762cce1e82493fe6 https://git.kernel.org/stable/c/757ba4d17b868482837c566cfefca59e2296c608

May 20, 2025 5:30 PM Description updated. Title updated. Added references View changes

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: parisc: Fix double SIGFPE crash Camm noticed that on parisc a SIGFPE exception will crash an application with a second SIGFPE in the signal handler. Dave analyzed it, and it happens because glibc uses a double-word floating-point store to atomically update function descriptors. As a result of lazy binding, we hit a floating-point store in fpe_func almost immediately. When the T bit is set, an assist exception trap occurs when when the co-processor encounters any floating-point instruction except for a double store of register %fr0. The latter cancels all pending traps. Let's fix this by clearing the Trap (T) bit in the FP status register before returning to the signal handler in userspace. The issue can be reproduced with this test program: root@parisc:~# cat fpe.c static void fpe_func(int sig, siginfo_t i, void v) { sigset_t set; sigemptyset(&set); sigaddset(&set, SIGFPE); sigprocmask(SIG_UNBLOCK, &set, NULL); printf("GOT signal %d with si_code %ld\n", sig, i->si_code); } int main() { struct sigaction action = { .sa_sigaction = fpe_func, .sa_flags = SA_RESTART\|SA_SIGINFO }; sigaction(SIGFPE, &action, 0); feenableexcept(FE_OVERFLOW); return printf("%lf\n",1.7976931348623158E3081.7976931348623158E308); } root@parisc:~# gcc fpe.c -lm root@parisc:~# ./a.out Floating point exception root@parisc:~# strace -f ./a.out execve("./a.out", ["./a.out"], 0xf9ac7034 / 20 vars /) = 0 getrlimit(RLIMIT_STACK, {rlim_cur=81921024, rlim_max=RLIM_INFINITY}) = 0 ... rt_sigaction(SIGFPE, {sa_handler=0x1110a, sa_mask=[], sa_flags=SA_RESTART\|SA_SIGINFO}, NULL, 8) = 0 --- SIGFPE {si_signo=SIGFPE, si_code=FPE_FLTOVF, si_addr=0x1078f} --- --- SIGFPE {si_signo=SIGFPE, si_code=FPE_FLTOVF, si_addr=0xf8f21237} --- +++ killed by SIGFPE +++ Floating point exception
Title		parisc: Fix double SIGFPE crash
References		https://git.kernel.org/stable/c/6a098c51d18ec99485668da44294565c43dbc106 https://git.kernel.org/stable/c/6c639af49e9e5615a8395981eaf5943fb40acd6f https://git.kernel.org/stable/c/cf21e890f56b7d0038ddaf25224e4f4c69ecd143 https://git.kernel.org/stable/c/de3629baf5a33af1919dec7136d643b0662e85ef https://git.kernel.org/stable/c/df3592e493d7f29bae4ffde9a9325de50ddf962e https://git.kernel.org/stable/c/ec4584495868bd465fe60a3f771915c0e7ce7951