================================================================== BUG: KASAN: use-after-free in rose_get_neigh+0x17c/0x480 net/rose/rose_route.c:692 Read of size 1 at addr ffff0000da5f3030 by task syz.1.893/7564 CPU: 0 PID: 7564 Comm: syz.1.893 Not tainted 6.1.138-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106 print_address_description+0x88/0x220 mm/kasan/report.c:316 print_report+0x50/0x68 mm/kasan/report.c:427 kasan_report+0xa8/0x100 mm/kasan/report.c:531 __asan_report_load1_noabort+0x2c/0x38 mm/kasan/report_generic.c:348 rose_get_neigh+0x17c/0x480 net/rose/rose_route.c:692 rose_connect+0x364/0xfe8 net/rose/af_rose.c:816 __sys_connect_file net/socket.c:2011 [inline] __sys_connect+0x264/0x28c net/socket.c:2028 __do_sys_connect net/socket.c:2038 [inline] __se_sys_connect net/socket.c:2035 [inline] __arm64_sys_connect+0x7c/0x94 net/socket.c:2035 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Allocated by task 7044: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:52 kasan_save_alloc_info+0x28/0x34 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa0/0xb8 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc_node_track_caller+0xe0/0x16c mm/slab_common.c:956 kmalloc_reserve net/core/skbuff.c:446 [inline] __alloc_skb+0x264/0x718 net/core/skbuff.c:515 alloc_skb include/linux/skbuff.h:1271 [inline] nlmsg_new include/net/netlink.h:991 [inline] netlink_ack+0x2f8/0xe60 net/netlink/af_netlink.c:2430 netlink_rcv_skb+0x1e4/0x3c4 net/netlink/af_netlink.c:2499 genl_rcv+0x38/0x50 net/netlink/genetlink.c:861 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline] netlink_unicast+0x600/0x818 net/netlink/af_netlink.c:1337 netlink_sendmsg+0x6e8/0x9b0 net/netlink/af_netlink.c:1859 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] __sys_sendto+0x304/0x3fc net/socket.c:2153 __do_sys_sendto net/socket.c:2165 [inline] __se_sys_sendto net/socket.c:2161 [inline] __arm64_sys_sendto+0xd8/0xf8 net/socket.c:2161 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Last potentially related work creation: kasan_save_stack+0x40/0x70 mm/kasan/common.c:45 __kasan_record_aux_stack+0xc0/0xdc mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:496 kvfree_call_rcu+0xb4/0x6f0 kernel/rcu/tree.c:3401 ma_put+0x10c/0x198 net/ipv6/mcast.c:869 __ipv6_dev_mc_dec+0x2b4/0x324 net/ipv6/mcast.c:982 ipv6_mc_destroy_dev+0x2bc/0x508 net/ipv6/mcast.c:2809 addrconf_ifdown+0x1188/0x15dc net/ipv6/addrconf.c:3944 addrconf_notify+0x2f4/0xca8 net/ipv6/addrconf.c:-1 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:455 call_netdevice_notifiers_info net/core/dev.c:2001 [inline] call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] unregister_netdevice_many+0xe2c/0x1740 net/core/dev.c:10978 ip6gre_exit_batch_net+0x418/0x468 net/ipv6/ip6_gre.c:1669 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x644/0xa74 net/core/net_namespace.c:640 process_one_work+0x7f4/0x13a8 kernel/workqueue.c:2292 worker_thread+0x8c8/0xfbc kernel/workqueue.c:2439 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864 The buggy address belongs to the object at ffff0000da5f3000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 48 bytes inside of 512-byte region [ffff0000da5f3000, ffff0000da5f3200) The buggy address belongs to the physical page: page:00000000fa83323d refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000da5f3800 pfn:0x11a5f0 head:00000000fa83323d order:2 compound_mapcount:0 compound_pincount:0 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 fffffc00030c1b08 fffffc0003d4b908 ffff0000c0002600 raw: ffff0000da5f3800 0000000000100001 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000da5f2f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000da5f2f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff0000da5f3000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000da5f3080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000da5f3100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Unable to handle kernel paging request at virtual address dfff800000000070 KASAN: null-ptr-deref in range [0x0000000000000380-0x0000000000000387] Mem abort info: ESR = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 [dfff800000000070] address between user and kernel address ranges Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 7564 Comm: syz.1.893 Tainted: G B 6.1.138-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : rose_link_up net/rose/rose_link.c:124 [inline] pc : rose_transmit_link+0xf4/0x66c net/rose/rose_link.c:271 lr : rose_link_up net/rose/rose_link.c:124 [inline] lr : rose_transmit_link+0xe8/0x66c net/rose/rose_link.c:271 sp : ffff8000214f7920 x29: ffff8000214f7920 x28: dfff800000000000 x27: 1ffff0000429ef34 x26: dfff800000000000 x25: ffff0000dcc58899 x24: ffff0000dcc58898 x23: ffff800013a8bec0 x22: 0000000000000037 x21: 0000000000000380 x20: ffff0000d4c568c0 x19: ffff0000da5f3000 x18: 0000000000000000 x17: ffff80000fc769c0 x16: ffff800008042940 x15: 0000000000000002 x14: 0000000000000000 x13: 0000000000ff0100 x12: 0000000000080000 x11: 00000000000004cd x10: ffff800021c7a000 x9 : ffff80001c2cd9d0 x8 : 0000000000000070 x7 : 0000000000000000 x6 : 000000000000002a x5 : ffff0000dcc588a0 x4 : ffff800013a8bec1 x3 : ffff800010a97884 x2 : 0000000000000000 x1 : 0000000000000008 x0 : 0000000000000000 Call trace: rose_link_up net/rose/rose_link.c:124 [inline] rose_transmit_link+0xf4/0x66c net/rose/rose_link.c:271 rose_write_internal+0xeec/0x17c0 net/rose/rose_subr.c:198 rose_connect+0x8bc/0xfe8 net/rose/af_rose.c:879 __sys_connect_file net/socket.c:2011 [inline] __sys_connect+0x264/0x28c net/socket.c:2028 __do_sys_connect net/socket.c:2038 [inline] __se_sys_connect net/socket.c:2035 [inline] __arm64_sys_connect+0x7c/0x94 net/socket.c:2035 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Code: 97d578b2 f94002a8 910e0115 d343fea8 (387a6908) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: 97d578b2 bl 0xffffffffff55e2c8 4: f94002a8 ldr x8, [x21] 8: 910e0115 add x21, x8, #0x380 c: d343fea8 lsr x8, x21, #3 * 10: 387a6908 ldrb w8, [x8, x26] <-- trapping instruction