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")).
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")).
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Redhat |
|
No data.
| Package | CPE | Advisory | Released Date |
|---|---|---|---|
| Red Hat Enterprise Linux 8 | |||
| kernel-rt-0:4.18.0-553.22.1.rt7.363.el8_10 | cpe:/a:redhat:enterprise_linux:8::nfv | RHSA-2024:7001 | 2024-09-24T00:00:00Z |
| kernel-0:4.18.0-553.22.1.el8_10 | cpe:/o:redhat:enterprise_linux:8 | RHSA-2024:7000 | 2024-09-24T00:00:00Z |
No data.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Mon, 04 Nov 2024 12:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Tue, 24 Sep 2024 11:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| CPEs | cpe:/o:redhat:enterprise_linux:8 |
Tue, 24 Sep 2024 06:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Redhat
Redhat enterprise Linux |
|
| CPEs | cpe:/a:redhat:enterprise_linux:8::nfv | |
| Vendors & Products |
Redhat
Redhat enterprise Linux |
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-05-04T07:12:53.351Z
Reserved: 2024-05-24T15:02:54.825Z
Link: CVE-2021-47527
Vulnrichment
Updated: 2024-08-04T05:39:59.783Z
NVD
Status : Awaiting Analysis
Published: 2024-05-24T15:15:15.580
Modified: 2024-11-21T06:36:27.393
Link: CVE-2021-47527
Redhat
OpenCVE Enrichment
No data.