CVE-2025-21820
tty: xilinx_uartps: split sysrq handling
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
In the Linux kernel, the following vulnerability has been resolved: tty: xilinx_uartps: split sysrq handling lockdep detects the following circular locking dependency: CPU 0 CPU 1
========================== ============================
cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the
port lock in cdns_uart_console_write if port->sysrq unset. However, if
(as shown above) cdns_uart_console_write runs before port->sysrq is set,
then it will try to take the port lock anyway. This may result in a
deadlock. Fix this by splitting sysrq handling into two parts. We use the prepare
helper under the port lock and defer handling until we release the lock.
In the Linux kernel, the following vulnerability has been resolved: tty: xilinx_uartps: split sysrq handling lockdep detects the following circular locking dependency: CPU 0 CPU 1 ========================== ============================ cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the port lock in cdns_uart_console_write if port->sysrq unset. However, if (as shown above) cdns_uart_console_write runs before port->sysrq is set, then it will try to take the port lock anyway. This may result in a deadlock. Fix this by splitting sysrq handling into two parts. We use the prepare helper under the port lock and defer handling until we release the lock.
Michael Randrianantenaina discovered that the Bluetooth driver in the Linux Kernel contained an improper access control vulnerability. A nearby attacker could use this to connect a rougue device and possibly execute arbitrary code. It was discovered that the CIFS network file system implementation in the Linux kernel did not properly verify the target namespace when handling upcalls. An attacker could use this to expose sensitive information.
CVSS Scores
SSVC
- Decision:-
Timeline
- 2024-12-29 CVE Reserved
- 2025-02-27 CVE Published
- 2025-05-04 CVE Updated
- 2025-06-29 EPSS Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
CAPEC
References (7)
URL | Tag | Source |
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https://git.kernel.org/stable/c/74ea66d4ca061a3cd4c0e924e51b60e924644852 | Vuln. Introduced |
URL | Date | SRC |
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URL | Date | SRC |
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Affected Vendors, Products, and Versions
Vendor | Product | Version | Other | Status | ||||||
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Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.6 < 5.15.179 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.6 < 5.15.179" | en |
Affected
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Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.6 < 6.1.129 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.6 < 6.1.129" | en |
Affected
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Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.6 < 6.6.78 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.6 < 6.6.78" | en |
Affected
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Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.6 < 6.12.14 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.6 < 6.12.14" | en |
Affected
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Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.6 < 6.13.3 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.6 < 6.13.3" | en |
Affected
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Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.6 < 6.14 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.6 < 6.14" | en |
Affected
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