CVE-2022-48635

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: fsdax: Reparar bucle infinito en dax_iomap_rw() Obtuve un bucle infinito y un informe de ADVERTENCIA al ejecutar un comando tail en virtiofs. ADVERTENCIA: CPU: 10 PID: 964 en fs/iomap/iter.c:34 iomap_iter+0x3a2/0x3d0 Módulos vinculados en: CPU: 10 PID: 964 Comm: tail No contaminado 5.19.0-rc7 Seguimiento de llamadas: dax_iomap_rw +0xea/0x620 ? __this_cpu_preempt_check+0x13/0x20 fuse_dax_read_iter+0x47/0x80 fuse_file_read_iter+0xae/0xd0 new_sync_read+0xfe/0x180 ? 0xffffffff81000000 vfs_read+0x14d/0x1a0 ksys_read+0x6d/0xf0 __x64_sys_read+0x1a/0x20 do_syscall_64+0x3b/0x90 Entry_SYSCALL_64_after_hwframe+0x63/0xcd El comando tail llamará a read() con un recuento de 0. En este caso, iomap_iter() informará esto ADVERTENCIA, y siempre devuelve 1, lo que provoca el bucle infinito en dax_iomap_rw(). Arreglando verificando el recuento si es 0 en dax_iomap_rw().

In the Linux kernel, the following vulnerability has been resolved: fsdax: Fix infinite loop in dax_iomap_rw() I got an infinite loop and a WARNING report when executing a tail command in virtiofs. WARNING: CPU: 10 PID: 964 at fs/iomap/iter.c:34 iomap_iter+0x3a2/0x3d0 Modules linked in: CPU: 10 PID: 964 Comm: tail Not tainted 5.19.0-rc7 Call Trace: <TASK> dax_iomap_rw+0xea/0x620 ? __this_cpu_preempt_check+0x13/0x20 fuse_dax_read_iter+0x47/0x80 fuse_file_read_iter+0xae/0xd0 new_sync_read+0xfe/0x180 ? 0xffffffff81000000 vfs_read+0x14d/0x1a0 ksys_read+0x6d/0xf0 __x64_sys_read+0x1a/0x20 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd The tail command will call read() with a count of 0. In this case, iomap_iter() will report this WARNING, and always return 1 which casuing the infinite loop in dax_iomap_rw(). Fixing by checking count whether is 0 in dax_iomap_rw().