Vulnerabilidad en kernel de Linux (CVE-2021-47126)

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ipv6: Corrección KASAN: slab-out-of-bounds Leer en fib6_nh_flush_exceptions Reportado por syzbot: HEAD commit: 90c911ad Merge tag 'fixes' de git://git.kernel.org /pub/scm.. árbol git: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git enlace del panel maestro: https://syzkaller.appspot.com/bug? extid=123aa35098fd3c000eb7 compilador: Debian clang versión 11.0.1-2 ===================================== ============================= ERROR: KASAN: losa fuera de los límites en fib6_nh_get_excptn_bucket net/ipv6/route.c: 1604 [en línea] ERROR: KASAN: losa fuera de los límites en fib6_nh_flush_exceptions+0xbd/0x360 net/ipv6/route.c:1732 Lectura de tamaño 8 en la dirección ffff8880145c78f8 por la tarea syz-executor.4/17760 CPU: 0 PID : 17760 Comm: syz-executor.4 No contaminado 5.12.0-rc8-syzkaller #0 Seguimiento de llamadas: __dump_stack lib/dump_stack.c:79 [en línea] dump_stack+0x202/0x31e lib/dump_stack.c:120 print_address_description +0x5f/0x3b0 mm/kasan/report.c:232 __kasan_report mm/kasan/report.c:399 [en línea] kasan_report+0x15c/0x200 mm/kasan/report.c:416 fib6_nh_get_excptn_bucket net/ipv6/route.c:1604 [en línea] fib6_nh_flush_exceptions+0xbd/0x360 net/ipv6/route.c:1732 fib6_nh_release+0x9a/0x430 net/ipv6/route.c:3536 fib6_info_destroy_rcu+0xcb/0x1c0 net/ipv6/ip6_fib.c:174 rcu_do_batch kernel /rcu/ tree.c:2559 [en línea] rcu_core+0x8f6/0x1450 kernel/rcu/tree.c:2794 __do_softirq+0x372/0x7a6 kernel/softirq.c:345 invoke_softirq kernel/softirq.c:221 [en línea] __irq_exit_rcu+0x22c/0x260 kernel/softirq.c:422 irq_exit_rcu+0x5/0x20 kernel/softirq.c:434 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/ include/asm/idtentry.h:632 RIP: 0010:lock_acquire+0x1f6/0x720 kernel/locking/lockdep.c:5515 Código: f6 84 24 a1 00 00 00 02 0f 85 8d 02 00 00 f7 c3 00 02 00 00 49 bd 00 00 00 00 00 fc ff df 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 4b c7 44 3d 09 00 00 00 00 43 c7 44 3d RSP: 0018:ffffc90009e06560 EFLAGS: 00000206 RAX: 1ffff920013c0cc0 RBX: 0000000000000246 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000 000000 RBP: ffffc90009e066e0 R08: dffffc0000000000 R09: ffffbfff1f992b1 R10: ffffbfff1f992b1 R11: 00000000000000000 R12: 0000000000000000 R13: dffff c0000000000 R14: 0000000000000000 R15: 1ffff920013c0cb4 rcu_lock_acquire+ 0x2a/0x30 include/linux/rcupdate.h:267 rcu_read_lock include/linux/rcupdate.h:656 [en línea] ext4_get_group_info+0xea/0x340 fs/ext4/ext4.h:3231 text4_mb_prefetch+0x123/0x5d0 fs/ext4/mballoc. c:2212 ext4_mb_regular_allocator+0x8a5/0x28f0 fs/ext4/mballoc.c:2379 ext4_mb_new_blocks+0xc6e/0x24f0 fs/ext4/mballoc.c:4982 ext4_ext_map_blocks+0x2be3/0x7210 fs/ext4/extents.c :4238 text4_map_blocks+0xab3/0x1cb0 fs/ext4/inode.c:638 text4_getblk+0x187/0x6c0 fs/ext4/inode.c:848 text4_bread+0x2a/0x1c0 fs/ext4/inode.c:900 text4_append+0x1a4/0x360 fs/ext4/namei.c: 67 ext4_init_new_dir+0x337/0xa10 fs/ext4/namei.c:2768 ext4_mkdir+0x4b8/0xc00 fs/ext4/namei.c:2814 vfs_mkdir+0x45b/0x640 fs/namei.c:3819 ovl_do_mkdir fs/overlayfs/over layfs.h: 161 [en línea] ovl_mkdir_real+0x53/0x1a0 fs/overlayfs/dir.c:146 ovl_create_real+0x280/0x490 fs/overlayfs/dir.c:193 ovl_workdir_create+0x425/0x600 fs/overlayfs/super.c:788 ovl_make_workdir+0 fijo/ 0x1140 fs/overlayfs/super.c:1355 ovl_get_workdir fs/overlayfs/super.c:1492 [en línea] ovl_fill_super+0x39ee/0x5370 fs/overlayfs/super.c:2035 mount_nodev+0x52/0xe0 fs/super.c:1413 Legacy_get_tree +0xea/0x180 fs/fs_context.c:592 vfs_get_tree+0x86/0x270 fs/super.c:1497 do_new_mount fs/namespace.c:2903 [en línea] path_mount+0x196f/0x2be0 fs/namespace.c:3233 do_mount fs/namespace .c:3246 [en línea]---truncado---