================================================================== BUG: KASAN: use-after-free in nr_add_node+0x1d68/0x1f3c net/netrom/nr_route.c:248 Read of size 2 at addr ffff0000f4741732 by task syz.1.72/4565 CPU: 1 PID: 4565 Comm: syz.1.72 Not tainted 6.1.130-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 lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x174/0x4c0 mm/kasan/report.c:427 kasan_report+0xd4/0x130 mm/kasan/report.c:531 __asan_report_load2_noabort+0x2c/0x38 mm/kasan/report_generic.c:349 nr_add_node+0x1d68/0x1f3c net/netrom/nr_route.c:248 nr_rt_ioctl+0xae0/0xd4c net/netrom/nr_route.c:651 nr_ioctl+0x14c/0x45c net/netrom/af_netrom.c:1254 sock_do_ioctl+0x134/0x2dc net/socket.c:1204 sock_ioctl+0x4f0/0x85c net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856 __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+0x58/0x168 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 4563: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:52 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:211 [inline] kmalloc_trace+0x7c/0x94 mm/slab_common.c:1031 kmalloc include/linux/slab.h:563 [inline] nr_add_node+0x778/0x1f3c net/netrom/nr_route.c:146 nr_rt_ioctl+0xae0/0xd4c net/netrom/nr_route.c:651 nr_ioctl+0x14c/0x45c net/netrom/af_netrom.c:1254 sock_do_ioctl+0x134/0x2dc net/socket.c:1204 sock_ioctl+0x4f0/0x85c net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856 __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+0x58/0x168 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 Freed by task 4565: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:52 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:516 ____kasan_slab_free+0x144/0x1c0 mm/kasan/common.c:236 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook mm/slub.c:1750 [inline] slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0x2c0/0x4b4 mm/slub.c:3674 kfree+0xcc/0x1b8 mm/slab_common.c:988 nr_neigh_put+0x144/0x1cc include/net/netrom.h:143 nr_add_node+0x1288/0x1f3c net/netrom/nr_route.c:246 nr_rt_ioctl+0xae0/0xd4c net/netrom/nr_route.c:651 nr_ioctl+0x14c/0x45c net/netrom/af_netrom.c:1254 sock_do_ioctl+0x134/0x2dc net/socket.c:1204 sock_ioctl+0x4f0/0x85c net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856 __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+0x58/0x168 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 The buggy address belongs to the object at ffff0000f4741700 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 50 bytes inside of 128-byte region [ffff0000f4741700, ffff0000f4741780) The buggy address belongs to the physical page: page:00000000473f15cb refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x134741 flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 dead000000000100 dead000000000122 ffff0000c0002300 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f4741600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000f4741680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff0000f4741700: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000f4741780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000f4741800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Unable to handle kernel paging request at virtual address e0e76077c000023a KASAN: maybe wild-memory-access in range [0x073f03be000011d0-0x073f03be000011d7] Mem abort info: ESR = 0x0000000096000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x04: level 0 translation fault Data abort info: ISV = 0, ISS = 0x00000004 CM = 0, WnR = 0 [e0e76077c000023a] address between user and kernel address ranges Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 4565 Comm: syz.1.72 Tainted: G B 6.1.130-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 : __hlist_del include/linux/list.h:884 [inline] pc : hlist_del_init include/linux/list.h:912 [inline] pc : __nr_remove_neigh net/netrom/nr_route.c:298 [inline] pc : nr_remove_neigh+0x6c/0xec net/netrom/nr_route.c:308 lr : __hlist_del include/linux/list.h:881 [inline] lr : hlist_del_init include/linux/list.h:912 [inline] lr : __nr_remove_neigh net/netrom/nr_route.c:298 [inline] lr : nr_remove_neigh+0x64/0xec net/netrom/nr_route.c:308 sp : ffff800021d476f0 x29: ffff800021d476f0 x28: ffff0000dbf86058 x27: 1fffe0001b7f0c03 x26: 0000000000000000 x25: dfff800000000000 x24: ffff0000dbf8601f x23: 1fffe0001b7f0c08 x22: dfff800000000000 x21: 0000000000000000 x20: 073f03be000011d5 x19: ffff0000f4741700 x18: ffff800021d47000 x17: 0000000000000000 x16: ffff800008976ba0 x15: 0000000000000002 x14: 00000000ffffffff x13: 0000000000000001 x12: ffff7000043a8ec4 x11: 1ffff000043a8ec4 x10: 0000000000000004 x9 : ffff80001cd859d0 x8 : 00e7e077c000023a x7 : 0000000000000001 x6 : ffff800011475194 x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff8000114751c8 x2 : 0000000000000000 x1 : 0000000000000008 x0 : 0000000000000000 Call trace: __hlist_del include/linux/list.h:881 [inline] hlist_del_init include/linux/list.h:912 [inline] __nr_remove_neigh net/netrom/nr_route.c:298 [inline] nr_remove_neigh+0x6c/0xec net/netrom/nr_route.c:308 nr_add_node+0x1798/0x1f3c net/netrom/nr_route.c:249 nr_rt_ioctl+0xae0/0xd4c net/netrom/nr_route.c:651 nr_ioctl+0x14c/0x45c net/netrom/af_netrom.c:1254 sock_do_ioctl+0x134/0x2dc net/socket.c:1204 sock_ioctl+0x4f0/0x85c net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856 __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+0x58/0x168 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: aa1303e0 97aad651 d343fe88 f9400275 (38766908) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: aa1303e0 mov x0, x19 4: 97aad651 bl 0xfffffffffeab5948 8: d343fe88 lsr x8, x20, #3 c: f9400275 ldr x21, [x19] * 10: 38766908 ldrb w8, [x8, x22] <-- trapping instruction