CVE-2025-21876
published 2025-03-27CVE-2025-21876: In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Fix suspicious RCU usage Commit ("iommu/vt-d: Allocate DMAR fault interrupts…
PriorityP419medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.20%
10.2th percentile
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Fix suspicious RCU usage
Commit ("iommu/vt-d: Allocate DMAR fault interrupts
locally") moved the call to enable_drhd_fault_handling() to a code
path that does not hold any lock while traversing the drhd list. Fix
it by ensuring the dmar_global_lock lock is held when traversing the
drhd list.
Without this fix, the following warning is triggered:
WARNING: suspicious RCU usage
6.14.0-rc3 #55 Not tainted
drivers/iommu/intel/dmar.c:2046 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 1
2 locks held by cpuhp/1/23:
#0: ffffffff84a67c50 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0
#1: ffffffff84a6a380 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0
stack backtrace:
CPU: 1 UID: 0 PID: 23 Comm: cpuhp/1 Not tainted 6.14.0-rc3 #55
Call Trace:
dump_stack_lvl+0xb7/0xd0
lockdep_rcu_suspicious+0x159/0x1f0
? __pfx_enable_drhd_fault_handling+0x10/0x10
enable_drhd_fault_handling+0x151/0x180
cpuhp_invoke_callback+0x1df/0x990
cpuhp_thread_fun+0x1ea/0x2c0
smpboot_thread_fn+0x1f5/0x2e0
? __pfx_smpboot_thread_fn+0x10/0x10
kthread+0x12a/0x2d0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x4a/0x60
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
Holding the lock in enable_drhd_fault_handling() triggers a lockdep splat
about a possible deadlock between dmar_global_lock and cpu_hotplug_lock.
This is avoided by not holding dmar_global_lock when calling
iommu_device_register(), which initiates the device probe process.
Affected
14 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | linux | < linux 6.12.19-1 (forky) | linux 6.12.19-1 (forky) |
| linux | linux | — | — |
| linux | linux | >= d74169ceb0d2e32438946a2f1f9fc8c803304bd6 < 4117c72938493a77ab53cc4b8284be8fb6ec8065 | 4117c72938493a77ab53cc4b8284be8fb6ec8065 |
| linux | linux | >= d74169ceb0d2e32438946a2f1f9fc8c803304bd6 < c603ccbe91d189849e1439134598ec567088dcec | c603ccbe91d189849e1439134598ec567088dcec |
| linux | linux | >= d74169ceb0d2e32438946a2f1f9fc8c803304bd6 < b150654f74bf0df8e6a7936d5ec51400d9ec06d8 | b150654f74bf0df8e6a7936d5ec51400d9ec06d8 |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 0 < 6.12.19-1 | 6.12.19-1 |
| linux | linux_kernel | >= 0 < 6.12.19-1 | 6.12.19-1 |
| linux | linux_kernel | >= 6.10 < 6.12.18 | 6.12.18 |
| linux | linux_kernel | >= 6.13 < 6.13.6 | 6.13.6 |
| ruby-lang | webrick | >= 0 < 1.8.2 | 1.8.2 |
CVSS provenance
nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_redhat5.9MEDIUM
vendor_debian5.5LOW
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GHSA
Ruby WEBrick read_headers method can lead to HTTP Request/Response Smuggling
ghsa·2025-06-26
CVE-2025-6442 [MEDIUM] CWE-444 Ruby WEBrick read_headers method can lead to HTTP Request/Response Smuggling
Ruby WEBrick read_headers method can lead to HTTP Request/Response Smuggling
Ruby WEBrick read_header HTTP Request Smuggling Vulnerability. This vulnerability allows remote attackers to smuggle arbitrary HTTP requests on affected installations of Ruby WEBrick. This issue is exploitable when the product is deployed behind an HTTP proxy that fulfills specific conditions.
The specific flaw exists within the read_headers method. The issue results from the inconsistent parsing of terminators of HTTP headers. An attacker can leverage this vulnerability to smuggle arbitrary HTTP requests. Was ZDI-CAN-21876.
OSV
linux-lowlatency, linux-lowlatency-hwe-6.11, linux-oracle vulnerabilities
osv·2025-05-28
linux-lowlatency, linux-lowlatency-hwe-6.11, linux-oracle vulnerabilities
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Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- PowerPC architecture;
- x86 architecture;
- Block layer subsystem;
- Serial ATA and Parallel ATA drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Character device driver;
- TPM device driver;
- Clock framework and drivers;
- Hardware crypto device drivers;
- FireWire subsystem;
- EFI core;
- Qualcomm firmware drivers;
- GPIO subsystem;
- GPU drivers;
- HID subsystem;
- I2C subsystem;
- I3C subsystem;
- InfiniBand drivers;
- Input Device (Mouse) drivers;
- IOMMU subsystem;
- Multiple dev
OSV
linux-aws vulnerabilities
osv·2025-05-22
linux-aws vulnerabilities
linux-aws vulnerabilities
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- PowerPC architecture;
- x86 architecture;
- Block layer subsystem;
- Serial ATA and Parallel ATA drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Character device driver;
- TPM device driver;
- Clock framework and drivers;
- Hardware crypto device drivers;
- FireWire subsystem;
- EFI core;
- Qualcomm firmware drivers;
- GPIO subsystem;
- GPU drivers;
- HID subsystem;
- I2C subsystem;
- I3C subsystem;
- InfiniBand drivers;
- Input Device (Mouse) drivers;
- IOMMU subsystem;
- Multiple devices driver;
- Media drivers;
- NVIDIA Tegra mem
OSV
linux, linux-azure, linux-azure-6.11, linux-gcp, linux-gcp-6.11, linux-hwe-6.11, linux-oem-6.11, linux-raspi, linux-realtime vulnerabilities
osv·2025-05-20
linux, linux-azure, linux-azure-6.11, linux-gcp, linux-gcp-6.11, linux-hwe-6.11, linux-oem-6.11, linux-raspi, linux-realtime vulnerabilities
linux, linux-azure, linux-azure-6.11, linux-gcp, linux-gcp-6.11, linux-hwe-6.11, linux-oem-6.11, linux-raspi, linux-realtime vulnerabilities
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- PowerPC architecture;
- x86 architecture;
- Block layer subsystem;
- Serial ATA and Parallel ATA drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Character device driver;
- TPM device driver;
- Clock framework and drivers;
- Hardware crypto device drivers;
- FireWire subsystem;
- EFI core;
- Qualcomm firmware drivers;
- GPIO subsystem;
- GPU drivers;
- HID subsystem;
- I2C subsystem;
- I3C subsystem;
- InfiniBand drivers
GHSA
GHSA-23g4-q58q-5pxc: In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Fix suspicious RCU usage
Commit ("iommu/vt-d: Allocate DMAR fault in
ghsa_unreviewed·2025-03-27
CVE-2025-21876 [MEDIUM] GHSA-23g4-q58q-5pxc: In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Fix suspicious RCU usage
Commit ("iommu/vt-d: Allocate DMAR fault in
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Fix suspicious RCU usage
Commit ("iommu/vt-d: Allocate DMAR fault interrupts
locally") moved the call to enable_drhd_fault_handling() to a code
path that does not hold any lock while traversing the drhd list. Fix
it by ensuring the dmar_global_lock lock is held when traversing the
drhd list.
Without this fix, the following warning is triggered:
WARNING: suspicious RCU usage
6.14.0-rc3 #55 Not tainted
drivers/iommu/intel/dmar.c:2046 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 1
2 locks held by cpuhp/1/23:
#0: ffffffff84a67c50 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0
#1: ffffffff84a6a380 (cpuhp_state-up){+.+
OSV
CVE-2025-21876: In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Fix suspicious RCU usage Commit ("iommu/vt-d: Allocate DMAR fault inte
osv·2025-03-27·CVSS 5.5
CVE-2025-21876 [MEDIUM] CVE-2025-21876: In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Fix suspicious RCU usage Commit ("iommu/vt-d: Allocate DMAR fault inte
In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Fix suspicious RCU usage Commit ("iommu/vt-d: Allocate DMAR fault interrupts locally") moved the call to enable_drhd_fault_handling() to a code path that does not hold any lock while traversing the drhd list. Fix it by ensuring the dmar_global_lock lock is held when traversing the drhd list. Without this fix, the following warning is triggered: ============================= WARNING: suspicious RCU usage 6.14.0-rc3 #55 Not tainted ----------------------------- drivers/iommu/intel/dmar.c:2046 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 2 locks held by cpuhp/1/23: #0: ffffffff84a67c50 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread
Red Hat
webrick: Ruby WEBrick Request Smuggling Vulnerability
vendor_redhat·2025-06-25·CVSS 5.9
CVE-2025-6442 [MEDIUM] CWE-444 webrick: Ruby WEBrick Request Smuggling Vulnerability
webrick: Ruby WEBrick Request Smuggling Vulnerability
Ruby WEBrick read_header HTTP Request Smuggling Vulnerability. This vulnerability allows remote attackers to smuggle arbitrary HTTP requests on affected installations of Ruby WEBrick. This issue is exploitable when the product is deployed behind an HTTP proxy that fulfills specific conditions.
The specific flaw exists within the read_headers method. The issue results from the inconsistent parsing of terminators of HTTP headers. An attacker can leverage this vulnerability to smuggle arbitrary HTTP requests. Was ZDI-CAN-21876.
A request smuggling vulnerability has been discovered in the Ruby WEBrick gem. This vulnerability is exploitable when the product is deployed behind a HTTP proxy that fulfills specific conditions.
Mitigation: Mit
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2025-05-28
CVE-2024-57977 Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- PowerPC architecture;
- x86 architecture;
- Block layer subsystem;
- Serial ATA and Parallel ATA drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Character device driver;
- TPM device driver;
- Clock framework and drivers;
- Hardware crypto device drivers;
- FireWire subsystem;
- EFI core;
- Qualcomm firmware drivers;
- GPIO subsystem;
- GPU drivers;
- HID subsystem;
- I2C subsystem;
- I3C subsystem;
- InfiniBand drivers;
- Input Device (Mouse) drivers;
- IOM
Ubuntu
Linux kernel (AWS) vulnerabilities
vendor_ubuntu·2025-05-22
CVE-2025-21716 Linux kernel (AWS) vulnerabilities
Title: Linux kernel (AWS) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- PowerPC architecture;
- x86 architecture;
- Block layer subsystem;
- Serial ATA and Parallel ATA drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Character device driver;
- TPM device driver;
- Clock framework and drivers;
- Hardware crypto device drivers;
- FireWire subsystem;
- EFI core;
- Qualcomm firmware drivers;
- GPIO subsystem;
- GPU drivers;
- HID subsystem;
- I2C subsystem;
- I3C subsystem;
- InfiniBand drivers;
- Input Device (Mouse) drivers;
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2025-05-20
CVE-2025-21716 Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- PowerPC architecture;
- x86 architecture;
- Block layer subsystem;
- Serial ATA and Parallel ATA drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Character device driver;
- TPM device driver;
- Clock framework and drivers;
- Hardware crypto device drivers;
- FireWire subsystem;
- EFI core;
- Qualcomm firmware drivers;
- GPIO subsystem;
- GPU drivers;
- HID subsystem;
- I2C subsystem;
- I3C subsystem;
- InfiniBand drivers;
- Input Device (Mouse) drivers;
- IOM
Red Hat
kernel: iommu/vt-d: Fix suspicious RCU usage
vendor_redhat·2025-03-27·CVSS 5.5
CVE-2025-21876 [MEDIUM] kernel: iommu/vt-d: Fix suspicious RCU usage
kernel: iommu/vt-d: Fix suspicious RCU usage
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Fix suspicious RCU usage
Commit ("iommu/vt-d: Allocate DMAR fault interrupts
locally") moved the call to enable_drhd_fault_handling() to a code
path that does not hold any lock while traversing the drhd list. Fix
it by ensuring the dmar_global_lock lock is held when traversing the
drhd list.
Without this fix, the following warning is triggered:
WARNING: suspicious RCU usage
6.14.0-rc3 #55 Not tainted
drivers/iommu/intel/dmar.c:2046 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 1
2 locks held by cpuhp/1/23:
#0: ffffffff84a67c50 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c
Debian
CVE-2025-21876: linux - In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d:...
vendor_debian·2025·CVSS 5.5
CVE-2025-21876 [MEDIUM] CVE-2025-21876: linux - In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d:...
In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Fix suspicious RCU usage Commit ("iommu/vt-d: Allocate DMAR fault interrupts locally") moved the call to enable_drhd_fault_handling() to a code path that does not hold any lock while traversing the drhd list. Fix it by ensuring the dmar_global_lock lock is held when traversing the drhd list. Without this fix, the following warning is triggered: ============================= WARNING: suspicious RCU usage 6.14.0-rc3 #55 Not tainted ----------------------------- drivers/iommu/intel/dmar.c:2046 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 2 locks held by cpuhp/1/23: #0: ffffffff84a67c50 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread
No detection rules found.
No public exploits indexed.
2025-03-27
Published