CVE-2026-43458

serial: caif: hold tty->link reference in ldisc_open and ser_release

State: Published
Severity: Not scored
Published: May 8, 2026
Updated: May 11, 2026
Reserved: May 1, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

serial: caif: hold tty->link reference in ldisc_open and ser_release

A reproducer triggers a KASAN slab-use-after-free in pty_write_room() when caif_serial's TX path calls tty_write_room(). The faulting access is on tty->link->port.

Hold an extra kref on tty->link for the lifetime of the caif_serial line discipline: get it in ldisc_open() and drop it in ser_release(), and also drop it on the ldisc_open() error path.

With this change applied, the reproducer no longer triggers the UAF in my testing.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	e31d5a05948e4478ba8396063d1e1f39880928e2 to before 23a3ac2e2262a291498567418227b99e1f3606b1Affected e31d5a05948e4478ba8396063d1e1f39880928e2 to before 52135420e9f75853ea0c6cea7b736e3e98495f7dAffected e31d5a05948e4478ba8396063d1e1f39880928e2 to before ca2ceba983bb23ea0202c2882d963253416654a3Affected e31d5a05948e4478ba8396063d1e1f39880928e2 to before 8460187b4852fd00bd1c76394358053f3fa4d089Affected e31d5a05948e4478ba8396063d1e1f39880928e2 to before 27e43356d0defb9fc7fa25265219a3ffeb7b3e98Affected e31d5a05948e4478ba8396063d1e1f39880928e2 to before 35b58d3bc716ebb9ebd10fe1cac8c1177242511cAffected e31d5a05948e4478ba8396063d1e1f39880928e2 to before 97a0bb491cae39478c6225381f14e9ac67b7bba7Affected e31d5a05948e4478ba8396063d1e1f39880928e2 to before 288598d80a068a0e9281de35bcb4ce495f189e2aAffected
LinuxLinux	2.6.35Affected before 2.6.35Not affected 5.10.253 through 5.10.Not affected 5.15.203 through 5.15.Not affected 6.1.167 through 6.1.Not affected 6.6.130 through 6.6.Not affected 6.12.78 through 6.12.Not affected 6.18.19 through 6.18.Not affected 6.19.9 through 6.19.*Not affected 7.0 and laterNot affected

Product

Versions

LinuxLinux

e31d5a05948e4478ba8396063d1e1f39880928e2 to before 23a3ac2e2262a291498567418227b99e1f3606b1Affected
e31d5a05948e4478ba8396063d1e1f39880928e2 to before 52135420e9f75853ea0c6cea7b736e3e98495f7dAffected
e31d5a05948e4478ba8396063d1e1f39880928e2 to before ca2ceba983bb23ea0202c2882d963253416654a3Affected
e31d5a05948e4478ba8396063d1e1f39880928e2 to before 8460187b4852fd00bd1c76394358053f3fa4d089Affected
e31d5a05948e4478ba8396063d1e1f39880928e2 to before 27e43356d0defb9fc7fa25265219a3ffeb7b3e98Affected
e31d5a05948e4478ba8396063d1e1f39880928e2 to before 35b58d3bc716ebb9ebd10fe1cac8c1177242511cAffected
e31d5a05948e4478ba8396063d1e1f39880928e2 to before 97a0bb491cae39478c6225381f14e9ac67b7bba7Affected
e31d5a05948e4478ba8396063d1e1f39880928e2 to before 288598d80a068a0e9281de35bcb4ce495f189e2aAffected

LinuxLinux

2.6.35Affected
before 2.6.35Not affected
5.10.253 through 5.10.*Not affected
5.15.203 through 5.15.*Not affected
6.1.167 through 6.1.*Not affected
6.6.130 through 6.6.*Not affected
6.12.78 through 6.12.*Not affected
6.18.19 through 6.18.*Not affected
6.19.9 through 6.19.*Not affected
7.0 and laterNot affected

References

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