CVE-2025-40348

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> slab: Avoid race on slab-&gt;obj_exts in alloc_slab_obj_exts<br /> <br /> If two competing threads enter alloc_slab_obj_exts() and one of them<br /> fails to allocate the object extension vector, it might override the<br /> valid slab-&gt;obj_exts allocated by the other thread with<br /> OBJEXTS_ALLOC_FAIL. This will cause the thread that lost this race and<br /> expects a valid pointer to dereference a NULL pointer later on.<br /> <br /> Update slab-&gt;obj_exts atomically using cmpxchg() to avoid<br /> slab-&gt;obj_exts overrides by racing threads.<br /> <br /> Thanks for Vlastimil and Suren&amp;#39;s help with debugging.