CVE-2021-47527
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2021-47527
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47527.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2021-47527
- Related
- Published
- 2024-05-24T15:15:15Z
- Modified
- 2024-09-18T03:18:51.956417Z
- Summary
- [none]
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
serial: core: fix transmit-buffer reset and memleak
Commit 761ed4a94582 ("tty: serialcore: convert uartclose to use ttyportclose") converted serial core to use ttyportclose() 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 uartputchar() 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
-
- https://git.kernel.org/stable/c/00de977f9e0aa9760d9a79d1e41ff780f74e3424
- https://git.kernel.org/stable/c/011f6c92b5bf6e1fbfdedc8b5232f64c1c493206
- https://git.kernel.org/stable/c/1179b168fa3f3a6aae3bd140000455a0e58457db
- https://git.kernel.org/stable/c/64e491c1634b73d3bddc081d08620bdc92ab2c12
- https://git.kernel.org/stable/c/c5da8aa441053958594f94254592bb41264bdfbf
- https://git.kernel.org/stable/c/e1722acf4f0d4d67b60f57e08ce16f8b66cd4b8f
- https://git.kernel.org/stable/c/e74d9663fd57640fc3394abb5c76fa95b9cc2f2e
- https://security-tracker.debian.org/tracker/CVE-2021-47527
Affected packages
Debian:11 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source
Debian:12 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source
Debian:13 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source