CVE-2024-26591

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: bpf: Se corrigió la rama de re-adjunción en bpf_tracing_prog_attach El siguiente caso puede causar un bloqueo debido a la falta de adjunto_btf: 1) cargar el programa rawtp 2) cargar el programa fentry con rawtp como target_fd 3) crear enlace de seguimiento para el programa fentry con target_fd = 0 4) repetir 3 Al final tenemos: - prog->aux->dst_trampoline == NULL - tgt_prog == NULL (porque no proporcionamos target_fd para link_create) - prog->aux ->attach_btf == NULL (el programa se cargó con adjunto_prog_fd=X) - el programa se cargó para tgt_prog pero no tenemos forma de averiguar cuál ERROR: desreferencia del puntero NULL del núcleo, dirección: 0000000000000058 Seguimiento de llamadas: ? __morir+0x20/0x70 ? page_fault_oops+0x15b/0x430? fixup_exception+0x22/0x330? exc_page_fault+0x6f/0x170? asm_exc_page_fault+0x22/0x30? bpf_tracing_prog_attach+0x279/0x560? btf_obj_id+0x5/0x10 bpf_tracing_prog_attach+0x439/0x560 __sys_bpf+0x1cf4/0x2de0 __x64_sys_bpf+0x1c/0x30 do_syscall_64+0x41/0xf0 Entry_SYSCALL_64_after_hwframe+0x6e/ 0x76 Devuelve -EINVAL en esta situación.

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix re-attachment branch in bpf_tracing_prog_attach The following case can cause a crash due to missing attach_btf: 1) load rawtp program 2) load fentry program with rawtp as target_fd 3) create tracing link for fentry program with target_fd = 0 4) repeat 3 In the end we have: - prog->aux->dst_trampoline == NULL - tgt_prog == NULL (because we did not provide target_fd to link_create) - prog->aux->attach_btf == NULL (the program was loaded with attach_prog_fd=X) - the program was loaded for tgt_prog but we have no way to find out which one BUG: kernel NULL pointer dereference, address: 0000000000000058 Call Trace: <TASK> ? __die+0x20/0x70 ? page_fault_oops+0x15b/0x430 ? fixup_exception+0x22/0x330 ? exc_page_fault+0x6f/0x170 ? asm_exc_page_fault+0x22/0x30 ? bpf_tracing_prog_attach+0x279/0x560 ? btf_obj_id+0x5/0x10 bpf_tracing_prog_attach+0x439/0x560 __sys_bpf+0x1cf4/0x2de0 __x64_sys_bpf+0x1c/0x30 do_syscall_64+0x41/0xf0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 Return -EINVAL in this situation.

Chih-Yen Chang discovered that the KSMBD implementation in the Linux kernel did not properly validate certain data structure fields when parsing lease contexts, leading to an out-of-bounds read vulnerability. A remote attacker could use this to cause a denial of service or possibly expose sensitive information. Quentin Minster discovered that a race condition existed in the KSMBD implementation in the Linux kernel, leading to a use-after-free vulnerability. A remote attacker could use this to cause a denial of service or possibly execute arbitrary code.