CVE Published: 03/04/2024 |
CVE Updated: 05/11/2024 |
CVE Year: 2024 Source: Linux |
Vendor: Linux |
Product: Linux Status : PUBLISHED
CVE-2024-26689 Description
In the Linux kernel, the following vulnerability has been resolved:
ceph: prevent use-after-free in encode_cap_msg()
In fs/ceph/caps.c, in encode_cap_msg(), "use after free" error was
caught by KASAN at this line - \'ceph_buffer_get(arg->xattr_buf);\'. This
implies before the refcount could be increment here, it was freed.
In same file, in "handle_cap_grant()" refcount is decremented by this
line - \'ceph_buffer_put(ci->i_xattrs.blob);\'. It appears that a race
occurred and resource was freed by the latter line before the former
line could increment it.
encode_cap_msg() is called by __send_cap() and __send_cap() is called by
ceph_check_caps() after calling __prep_cap(). __prep_cap() is where
arg->xattr_buf is assigned to ci->i_xattrs.blob. This is the spot where
the refcount must be increased to prevent "use after free" error.