CVE-2026-43458

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

HIGH
7.8
CVSS Score
Published: May 8, 2026 at 02:22 PM UTC
Updated: June 17, 2026 at 10:49 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.8
Exploit prediction
EPSS 0.1%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2.6.35 ≤ v < 5.10.2532.6.35 ≤ v < 5.15.2032.6.35 ≤ v < 6.1.1672.6.35 ≤ v < 6.12.782.6.35 ≤ v < 6.18.192.6.35 ≤ v < 6.19.92.6.35 ≤ v < 6.6.1302.6.35 ≤ v < 7.05.11 ≤ v < 5.15.2035.16 ≤ v < 6.1.1676.13 ≤ v < 6.18.196.19 ≤ v < 6.19.96.2 ≤ v < 6.6.1306.7 ≤ v < 6.12.782.6.357.0 rc17.0 rc27.0 rc3e31d5a05948e4478ba8396063d1e1f39880928e2
Vendor states this is fixed in 23a3ac2e2262a291498567418227b99e1f3606b1 (fixed)
Vendor states this is fixed in 27e43356d0defb9fc7fa25265219a3ffeb7b3e98 (fixed)
Vendor states this is fixed in 288598d80a068a0e9281de35bcb4ce495f189e2a (fixed)
Vendor states this is fixed in 35b58d3bc716ebb9ebd10fe1cac8c1177242511c (fixed)
Vendor states this is fixed in 52135420e9f75853ea0c6cea7b736e3e98495f7d (fixed)
Vendor states this is fixed in 8460187b4852fd00bd1c76394358053f3fa4d089 (fixed)
Vendor states this is fixed in 97a0bb491cae39478c6225381f14e9ac67b7bba7 (fixed)
Vendor states this is fixed in ca2ceba983bb23ea0202c2882d963253416654a3 (fixed)
Vendor states this is fixed in 2.6.35 (unaffected)
Vendor states this is fixed in 5.10.253 (unaffected)
Vendor states this is fixed in 5.15.203 (unaffected)
Vendor states this is fixed in 6.1.167 (unaffected)
Vendor states this is fixed in 6.12.78 (unaffected)
Vendor states this is fixed in 6.18.19 (unaffected)
Vendor states this is fixed in 6.19.9 (unaffected)
Vendor states this is fixed in 6.6.130 (unaffected)
Vendor states this is fixed in 7.0 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-416

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