CVE - CVE-2021-47527

CVE-ID
CVE-2021-47527	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
In the Linux kernel, the following vulnerability has been resolved: serial: core: fix transmit-buffer reset and memleak Commit 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") converted serial core to use tty_port_close() but failed to notice that the transmit buffer still needs to be freed on final close. Not freeing the transmit buffer means that the buffer is no longer cleared on next open so that any ioctl() waiting for the buffer to drain might wait indefinitely (e.g. on termios changes) or that stale data can end up being transmitted in case tx is restarted. Furthermore, the buffer of any port that has been opened would leak on driver unbind. Note that the port lock is held when clearing the buffer pointer due to the ldisc race worked around by commit a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()"). Also note that the tty-port shutdown() callback is not called for console ports so it is not strictly necessary to free the buffer page after releasing the lock (cf. d72402145ace ("tty/serial: do not free trasnmit buffer page under port lock")).
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://git.kernel.org/stable/c/00de977f9e0aa9760d9a79d1e41ff780f74e3424 URL:https://git.kernel.org/stable/c/00de977f9e0aa9760d9a79d1e41ff780f74e3424 MISC:https://git.kernel.org/stable/c/011f6c92b5bf6e1fbfdedc8b5232f64c1c493206 URL:https://git.kernel.org/stable/c/011f6c92b5bf6e1fbfdedc8b5232f64c1c493206 MISC:https://git.kernel.org/stable/c/1179b168fa3f3a6aae3bd140000455a0e58457db URL:https://git.kernel.org/stable/c/1179b168fa3f3a6aae3bd140000455a0e58457db MISC:https://git.kernel.org/stable/c/64e491c1634b73d3bddc081d08620bdc92ab2c12 URL:https://git.kernel.org/stable/c/64e491c1634b73d3bddc081d08620bdc92ab2c12 MISC:https://git.kernel.org/stable/c/c5da8aa441053958594f94254592bb41264bdfbf URL:https://git.kernel.org/stable/c/c5da8aa441053958594f94254592bb41264bdfbf MISC:https://git.kernel.org/stable/c/e1722acf4f0d4d67b60f57e08ce16f8b66cd4b8f URL:https://git.kernel.org/stable/c/e1722acf4f0d4d67b60f57e08ce16f8b66cd4b8f MISC:https://git.kernel.org/stable/c/e74d9663fd57640fc3394abb5c76fa95b9cc2f2e URL:https://git.kernel.org/stable/c/e74d9663fd57640fc3394abb5c76fa95b9cc2f2e
Assigning CNA
kernel.org
Date Record Created
20240524	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20240524)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
This is an record on the CVE List, which provides common identifiers for publicly known cybersecurity vulnerabilities.
Search CVE Using Keywords: You can also search by reference using the CVE Reference Maps.
For More Information: CVE Request Web Form (select "Other" from dropdown)