CVE-2023-52621

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: bpf: verifique rcu_read_lock_trace_held() antes de llamar a los ayudantes de mapas de bpf. Estos tres ayudantes de bpf_map_{lookup,update,delete}_elem() también están disponibles para el programa bpf que se puede dormir, así que agregue el bloqueo correspondiente. aserción para el programa bpf con capacidad para dormir; de lo contrario, se informará la siguiente advertencia cuando un programa bpf con capacidad para dormir manipule el mapa bpf en modo intérprete (también conocido como bpf_jit_enable=0): ADVERTENCIA: CPU: 3 PID: 4985 en kernel/bpf/helpers.c:40. ..... CPU: 3 PID: 4985 Comm: test_progs Not tainted 6.6.0+ #2 Nombre del hardware: PC estándar QEMU (i440FX + PIIX, 1996) ...... RIP: 0010:bpf_map_lookup_elem+0x54/0x60 ...... Seguimiento de llamadas: ? __advertir+0xa5/0x240 ? bpf_map_lookup_elem+0x54/0x60? report_bug+0x1ba/0x1f0? handle_bug+0x40/0x80? exc_invalid_op+0x18/0x50? asm_exc_invalid_op+0x1b/0x20? __pfx_bpf_map_lookup_elem+0x10/0x10 ? rcu_lockdep_current_cpu_online+0x65/0xb0? rcu_is_watching+0x23/0x50? bpf_map_lookup_elem+0x54/0x60? __pfx_bpf_map_lookup_elem+0x10/0x10 ___bpf_prog_run+0x513/0x3b70 __bpf_prog_run32+0x9d/0xd0 ? __bpf_prog_enter_sleepable_recur+0xad/0x120 ? __bpf_prog_enter_sleepable_recur+0x3e/0x120 bpf_trampoline_6442580665+0x4d/0x1000 __x64_sys_getpgid+0x5/0x30 ? do_syscall_64+0x36/0xb0 entrada_SYSCALL_64_after_hwframe+0x6e/0x76

In the Linux kernel, the following vulnerability has been resolved: bpf: Check rcu_read_lock_trace_held() before calling bpf map helpers These three bpf_map_{lookup,update,delete}_elem() helpers are also available for sleepable bpf program, so add the corresponding lock assertion for sleepable bpf program, otherwise the following warning will be reported when a sleepable bpf program manipulates bpf map under interpreter mode (aka bpf_jit_enable=0): WARNING: CPU: 3 PID: 4985 at kernel/bpf/helpers.c:40 ...... CPU: 3 PID: 4985 Comm: test_progs Not tainted 6.6.0+ #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...... RIP: 0010:bpf_map_lookup_elem+0x54/0x60 ...... Call Trace: <TASK> ? __warn+0xa5/0x240 ? bpf_map_lookup_elem+0x54/0x60 ? report_bug+0x1ba/0x1f0 ? handle_bug+0x40/0x80 ? exc_invalid_op+0x18/0x50 ? asm_exc_invalid_op+0x1b/0x20 ? __pfx_bpf_map_lookup_elem+0x10/0x10 ? rcu_lockdep_current_cpu_online+0x65/0xb0 ? rcu_is_watching+0x23/0x50 ? bpf_map_lookup_elem+0x54/0x60 ? __pfx_bpf_map_lookup_elem+0x10/0x10 ___bpf_prog_run+0x513/0x3b70 __bpf_prog_run32+0x9d/0xd0 ? __bpf_prog_enter_sleepable_recur+0xad/0x120 ? __bpf_prog_enter_sleepable_recur+0x3e/0x120 bpf_trampoline_6442580665+0x4d/0x1000 __x64_sys_getpgid+0x5/0x30 ? do_syscall_64+0x36/0xb0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 </TASK>

Alon Zahavi discovered that the NVMe-oF/TCP subsystem in the Linux kernel did not properly validate H2C PDU data, leading to a null pointer dereference vulnerability. A remote attacker could use this to cause a denial of service. Sander Wiebing, Alvise de Faveri Tron, Herbert Bos, and Cristiano Giuffrida discovered that the Linux kernel mitigations for the initial Branch History Injection vulnerability were insufficient for Intel processors. A local attacker could potentially use this to expose sensitive information.