CVE-2021-47527
Linux Kernel Serial Buffer Memory Leak and Data Corruption Vulnerability
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")).
INFO
Published Date :
May 24, 2024, 3:15 p.m.
Last Modified :
Nov. 21, 2024, 6:36 a.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
Exploitability Score :
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-47527.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-47527 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47527 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/00de977f9e0aa9760d9a79d1e41ff780f74e3424 Added Reference https://git.kernel.org/stable/c/011f6c92b5bf6e1fbfdedc8b5232f64c1c493206 Added Reference https://git.kernel.org/stable/c/1179b168fa3f3a6aae3bd140000455a0e58457db Added Reference https://git.kernel.org/stable/c/64e491c1634b73d3bddc081d08620bdc92ab2c12 Added Reference https://git.kernel.org/stable/c/c5da8aa441053958594f94254592bb41264bdfbf Added Reference https://git.kernel.org/stable/c/e1722acf4f0d4d67b60f57e08ce16f8b66cd4b8f Added Reference https://git.kernel.org/stable/c/e74d9663fd57640fc3394abb5c76fa95b9cc2f2e -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 24, 2024
Action Type Old Value New Value Added 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")). Added Reference kernel.org https://git.kernel.org/stable/c/011f6c92b5bf6e1fbfdedc8b5232f64c1c493206 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/e74d9663fd57640fc3394abb5c76fa95b9cc2f2e [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/1179b168fa3f3a6aae3bd140000455a0e58457db [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/c5da8aa441053958594f94254592bb41264bdfbf [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/e1722acf4f0d4d67b60f57e08ce16f8b66cd4b8f [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/64e491c1634b73d3bddc081d08620bdc92ab2c12 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/00de977f9e0aa9760d9a79d1e41ff780f74e3424 [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47527 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-47527
weaknesses.