FreeBSD-SA-26:63.posixshm

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-26:63.posixshm Security Advisory The FreeBSD Project Topic: TOCTOU race in POSIX shared memory large page configuration Category: core Module: posixshm...

CVE-2026-49428 posixshm: system calls can incorrectly free memory of largepage objects

Certain system calls, such open2 with the OTRUNC flag set, and fspacectl2, could incorrectly free memory in largepage objects. These operations are not permitted on largepage objects, but the implementation did not verify this. An unprivileged local user can abuse the bug to access freed kernel...

CVE-2026-49428

FreeBSD is vulnerable to a flaw in its posixshm module involving largepage shared memory objects. Specifically, certain system calls such as open(2) with the O_TRUNC flag and fspacectl(2) fail to verify that these operations are prohibited on largepage objects, leading to the incorrect freeing of...

CVE-2026-49428 posixshm: system calls can incorrectly free memory of largepage objects

Certain system calls, such open2 with the OTRUNC flag set, and fspacectl2, could incorrectly free memory in largepage objects. These operations are not permitted on largepage objects, but the implementation did not verify this. An unprivileged local user can abuse the bug to access freed kernel...

CVE-2026-49427 posixshm: largepage shared memory objects not explicitly wired

Pages belonging to largepage shared memory objects were not explicitly wired. When sendfile2 transmitted such an object with the SFNOCACHE flag, it freed the underlying pages after transmission even though existing mappings still referred to them. An unprivileged local user can abuse the bug to...

CVE-2026-49427

The FreeBSD kernel's posixshm module contains a vulnerability where pages belonging to largepage shared memory objects were not explicitly wired. When sendfile(2) transmits such an object with the SF_NOCACHE flag, it incorrectly frees the underlying pages while existing mappings still refer to th...

CVE-2026-49427 posixshm: largepage shared memory objects not explicitly wired

Pages belonging to largepage shared memory objects were not explicitly wired. When sendfile2 transmitted such an object with the SFNOCACHE flag, it freed the underlying pages after transmission even though existing mappings still referred to them. An unprivileged local user can abuse the bug to...