==================================================================
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