"value":"In the Linux kernel, the following vulnerability has been resolved:\n\nftrace: Fix possible use-after-free issue in ftrace_location()\n\nKASAN reports a bug:\n\n BUG: KASAN: use-after-free in ftrace_location+0x90/0x120\n Read of size 8 at addr ffff888141d40010 by task insmod/424\n CPU: 8 PID: 424 Comm: insmod Tainted: G W 6.9.0-rc2+\n [...]\n Call Trace:\n <TASK>\n dump_stack_lvl+0x68/0xa0\n print_report+0xcf/0x610\n kasan_report+0xb5/0xe0\n ftrace_location+0x90/0x120\n register_kprobe+0x14b/0xa40\n kprobe_init+0x2d/0xff0 [kprobe_example]\n do_one_initcall+0x8f/0x2d0\n do_init_module+0x13a/0x3c0\n load_module+0x3082/0x33d0\n init_module_from_file+0xd2/0x130\n __x64_sys_finit_module+0x306/0x440\n do_syscall_64+0x68/0x140\n entry_SYSCALL_64_after_hwframe+0x71/0x79\n\nThe root cause is that, in lookup_rec(), ftrace record of some address\nis being searched in ftrace pages of some module, but those ftrace pages\nat the same time is being freed in ftrace_release_mod() as the\ncorresponding module is being deleted:\n\n CPU1 | CPU2\n register_kprobes() { | delete_module() {\n check_kprobe_address_safe() { |\n arch_check_ftrace_location() { |\n ftrace_location() { |\n lookup_rec() // USE! | ftrace_release_mod() // Free!\n\nTo fix this issue:\n 1. Hold rcu lock as accessing ftrace pages in ftrace_location_range();\n 2. Use ftrace_location_range() instead of lookup_rec() in\n ftrace_location();\n 3. Call synchronize_rcu() before freeing any ftrace pages both in\n ftrace_process_locs()/ftrace_release_mod()/ftrace_free_mem()."
"value":"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ftrace: Solucionar posible problema de use-after-free en ftrace_location() KASAN informa un error: ERROR: KASAN: use-after-free en ftrace_location+0x90/0x120 Lectura de tama\u00f1o 8 en addr ffff888141d40010 por tarea insmod/424 CPU: 8 PID: 424 Comm: insmod Tainted: GW 6.9.0-rc2+ [...] Rastreo de llamadas: dump_stack_lvl+0x68/0xa0 print_report+0xcf/0x610 kasan_report+0xb5/ 0xe0 ftrace_location+0x90/0x120 Register_kprobe+0x14b/0xa40 kprobe_init+0x2d/0xff0 [kprobe_example] do_one_initcall+0x8f/0x2d0 do_init_module+0x13a/0x3c0 load_module+0x3082/0x33d0 init_module_from _file+0xd2/0x130 __x64_sys_finit_module+0x306/0x440 do_syscall_64+0x68/0x140 entrada_SYSCALL_64_after_hwframe +0x71/0x79 La causa principal es que, en lookup_rec(), el registro ftrace de alguna direcci\u00f3n se busca en las p\u00e1ginas ftrace de alg\u00fan m\u00f3dulo, pero esas p\u00e1ginas ftrace al mismo tiempo se liberan en ftrace_release_mod() como lo est\u00e1 el m\u00f3dulo correspondiente. siendo eliminado: CPU1 | CPU2 registro_kprobes() { | eliminar_m\u00f3dulo() { check_kprobe_address_safe() { | arch_check_ftrace_location() { | ftrace_ubicaci\u00f3n() { | lookup_rec() // \u00a1UTILIZAR! | ftrace_release_mod() // \u00a1Gratis! Para solucionar este problema: 1. Mantenga presionado rcu lock mientras accede a las p\u00e1ginas de ftrace en ftrace_location_range(); 2. Utilice ftrace_location_range() en lugar de lookup_rec() en ftrace_location(); 3. Llame a sincronizar_rcu() antes de liberar cualquier p\u00e1gina ftrace tanto en ftrace_process_locs()/ftrace_release_mod()/ftrace_free_mem()."
