[v5.15] WARNING: ODEBUG bug in ax25_dev_device_down
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syzbot
Jul 4, 2025, 3:13:38 PMJul 4
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 3dea0e7f549e Linux 5.15.186
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=143ccc8c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=fe91feccd8127a59
dashboard link: https://syzkaller.appspot.com/bug?extid=8bedf4107d4cce2e27e2
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: arm64
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e8db6cfea7ea/disk-3dea0e7f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/eeb133c8268e/vmlinux-3dea0e7f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9478525201a1/Image-3dea0e7f.gz.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8bedf4...@syzkaller.appspotmail.com
------------[ cut here ]------------
ODEBUG: assert_init not available (active state 0) object type: timer_list hint: 0x0
WARNING: CPU: 0 PID: 5156 at lib/debugobjects.c:521 debug_print_object+0x148/0x1d4 lib/debugobjects.c:518
Modules linked in:
CPU: 0 PID: 5156 Comm: syz.3.271 Not tainted 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : debug_print_object+0x148/0x1d4 lib/debugobjects.c:518
lr : debug_print_object+0x148/0x1d4 lib/debugobjects.c:518
sp : ffff800020797560
x29: ffff800020797560 x28: ffff8000163e5ce0 x27: 0000000000000002
x26: ffff800014180000 x25: ffff80000837e250 x24: dfff800000000000
x23: 0000000000000000 x22: 0000000000000000 x21: ffff8000117da4e0
x20: ffff800011342ce0 x19: ffff8000117da020 x18: 0000000000000202
x17: 0000000000000002 x16: ffff8000111cf35c x15: 00000000ffffffff
x14: 0000000000ff0100 x13: 0000000000000001 x12: 0000000000080000
x11: 00000000000153b3 x10: ffff800025a19000 x9 : 9542690dbeb0df00
x8 : 9542690dbeb0df00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800020796e58 x4 : ffff80001425f400 x3 : ffff800008505198
x2 : 0000000000000001 x1 : 0000000000000201 x0 : 0000000000000054
Call trace:
debug_print_object+0x148/0x1d4 lib/debugobjects.c:518
debug_object_assert_init+0x24c/0x2c4 lib/debugobjects.c:894
debug_timer_assert_init kernel/time/timer.c:739 [inline]
debug_assert_init kernel/time/timer.c:784 [inline]
del_timer+0x48/0x1e4 kernel/time/timer.c:1224
ax25_ds_del_timer+0x28/0x40 net/ax25/ax25_ds_timer.c:47
ax25_dev_device_down+0x6c/0x67c net/ax25/ax25_dev.c:106
ax25_device_event+0x538/0x590 net/ax25/af_ax25.c:144
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391
call_netdevice_notifiers_info net/core/dev.c:2049 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
call_netdevice_notifiers net/core/dev.c:2075 [inline]
__dev_notify_flags+0x250/0x46c net/core/dev.c:-1
dev_change_flags+0xc8/0x154 net/core/dev.c:8929
dev_ifsioc+0x504/0xef4 net/core/dev_ioctl.c:324
dev_ioctl+0x4d0/0xc94 net/core/dev_ioctl.c:587
sock_do_ioctl+0x18c/0x240 net/socket.c:1154
sock_ioctl+0x5c8/0x87c net/socket.c:1257
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
irq event stamp: 1235
hardirqs last enabled at (1234): [<ffff8000082f8f64>] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:257
hardirqs last disabled at (1235): [<ffff8000111cabbc>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:396
softirqs last enabled at (1212): [<ffff800010467650>] ax25_rt_device_down+0x148/0x164 net/ax25/ax25_route.c:69
softirqs last disabled at (1214): [<ffff800010461988>] spin_lock_bh include/linux/spinlock.h:368 [inline]
softirqs last disabled at (1214): [<ffff800010461988>] ax25_dev_device_down+0x64/0x67c net/ax25/ax25_dev.c:103
---[ end trace f73cfca4066bb13e ]---
==================================================================
BUG: KASAN: slab-out-of-bounds in lockdep_init_map_type+0x4d8/0x6d4 kernel/locking/lockdep.c:4783
Write of size 1 at addr ffff0000db7a24a8 by task syz.3.271/5156
CPU: 0 PID: 5156 Comm: syz.3.271 Tainted: G W 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call trace:
dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
__dump_stack+0x30/0x40 lib/dump_stack.c:88
dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106
print_address_description+0x78/0x30c mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:434 [inline]
kasan_report+0xec/0x15c mm/kasan/report.c:451
__asan_report_store1_noabort+0x44/0x50 mm/kasan/report_generic.c:311
lockdep_init_map_type+0x4d8/0x6d4 kernel/locking/lockdep.c:4783
lockdep_init_map_waits include/linux/lockdep.h:195 [inline]
lockdep_init_map_wait include/linux/lockdep.h:202 [inline]
lockdep_init_map include/linux/lockdep.h:208 [inline]
do_init_timer kernel/time/timer.c:797 [inline]
init_timer_key+0x198/0x418 kernel/time/timer.c:817
timer_fixup_assert_init+0x58/0x78 kernel/time/timer.c:705
debug_object_fixup lib/debugobjects.c:534 [inline]
debug_object_assert_init+0x278/0x2c4 lib/debugobjects.c:895
debug_timer_assert_init kernel/time/timer.c:739 [inline]
debug_assert_init kernel/time/timer.c:784 [inline]
del_timer+0x48/0x1e4 kernel/time/timer.c:1224
ax25_ds_del_timer+0x28/0x40 net/ax25/ax25_ds_timer.c:47
ax25_dev_device_down+0x6c/0x67c net/ax25/ax25_dev.c:106
ax25_device_event+0x538/0x590 net/ax25/af_ax25.c:144
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391
call_netdevice_notifiers_info net/core/dev.c:2049 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
call_netdevice_notifiers net/core/dev.c:2075 [inline]
__dev_notify_flags+0x250/0x46c net/core/dev.c:-1
dev_change_flags+0xc8/0x154 net/core/dev.c:8929
dev_ifsioc+0x504/0xef4 net/core/dev_ioctl.c:324
dev_ioctl+0x4d0/0xc94 net/core/dev_ioctl.c:587
sock_do_ioctl+0x18c/0x240 net/socket.c:1154
sock_ioctl+0x5c8/0x87c net/socket.c:1257
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Allocated by task 4037:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc mm/kasan/common.c:513 [inline]
__kasan_kmalloc+0xb0/0xf0 mm/kasan/common.c:522
kasan_kmalloc include/linux/kasan.h:264 [inline]
__kmalloc_node+0x2bc/0x520 mm/slub.c:4455
kmalloc_array_node include/linux/slab.h:697 [inline]
kcalloc_node include/linux/slab.h:702 [inline]
memcg_alloc_page_obj_cgroups+0x80/0x174 mm/memcontrol.c:2839
memcg_slab_post_alloc_hook mm/slab.h:313 [inline]
slab_post_alloc_hook+0xc0/0x408 mm/slab.h:526
slab_alloc_node mm/slub.c:3220 [inline]
slab_alloc mm/slub.c:3228 [inline]
kmem_cache_alloc+0x1e0/0x3e4 mm/slub.c:3233
__d_alloc+0x3c/0x65c fs/dcache.c:1749
d_alloc_pseudo+0x28/0x8c fs/dcache.c:1878
alloc_file_pseudo+0xcc/0x1dc fs/file_table.c:256
sock_alloc_file+0xb4/0x22c net/socket.c:462
sock_map_fd net/socket.c:486 [inline]
__sys_socket+0x13c/0x18c net/socket.c:1588
__do_sys_socket net/socket.c:1593 [inline]
__se_sys_socket net/socket.c:1591 [inline]
__arm64_sys_socket+0x7c/0x94 net/socket.c:1591
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
The buggy address belongs to the object at ffff0000db7a2400
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 168 bytes inside of
256-byte region [ffff0000db7a2400, ffff0000db7a2500)
The buggy address belongs to the page:
page:000000004caa20af refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11b7a2
head:000000004caa20af order:1 compound_mapcount:0
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 fffffc00033b5c80 0000000300000003 ffff0000c0002480
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff0000db7a2380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff0000db7a2400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000db7a2480: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
^
ffff0000db7a2500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff0000db7a2580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 5156 at lib/refcount.c:28 refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28
Modules linked in:
CPU: 1 PID: 5156 Comm: syz.3.271 Tainted: G B W 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28
lr : refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28
sp : ffff800020797690
x29: ffff800020797690 x28: ffff8000163e5ce0 x27: 1fffe0001b6f4482
x26: ffff80001b1f5000 x25: 1fffe000199a786d x24: dfff800000000000
x23: 0000000000000000 x22: ffff0000db7a24b8 x21: ffff0000ccd3c000
x20: ffff0000db7a24b8 x19: ffff8000165c3000 x18: 0000000000000002
x17: 0000000040000000 x16: ffff8000111cf35c x15: 0000000000000002
x14: 0000000000ff0100 x13: ffffffffffffffff x12: 0000000000080000
x11: 000000000004aa7c x10: ffff800025a19000 x9 : 9542690dbeb0df00
x8 : 9542690dbeb0df00 x7 : 0000000000000000 x6 : ffff80000824599c
x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800008505198
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000026
Call trace:
refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28
__refcount_sub_and_test include/linux/refcount.h:283 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
ax25_dev_put include/net/ax25.h:301 [inline]
ax25_dev_device_down+0x4d4/0x67c net/ax25/ax25_dev.c:119
ax25_device_event+0x538/0x590 net/ax25/af_ax25.c:144
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391
call_netdevice_notifiers_info net/core/dev.c:2049 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
call_netdevice_notifiers net/core/dev.c:2075 [inline]
__dev_notify_flags+0x250/0x46c net/core/dev.c:-1
dev_change_flags+0xc8/0x154 net/core/dev.c:8929
dev_ifsioc+0x504/0xef4 net/core/dev_ioctl.c:324
dev_ioctl+0x4d0/0xc94 net/core/dev_ioctl.c:587
sock_do_ioctl+0x18c/0x240 net/socket.c:1154
sock_ioctl+0x5c8/0x87c net/socket.c:1257
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
irq event stamp: 1243
hardirqs last enabled at (1242): [<ffff8000112a9454>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
hardirqs last enabled at (1242): [<ffff8000112a9454>] _raw_spin_unlock_irqrestore+0xa8/0x14c kernel/locking/spinlock.c:194
hardirqs last disabled at (1243): [<ffff8000112a8f50>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
hardirqs last disabled at (1243): [<ffff8000112a8f50>] _raw_spin_lock_irqsave+0xfc/0x14c kernel/locking/spinlock.c:162
softirqs last enabled at (1212): [<ffff800010467650>] ax25_rt_device_down+0x148/0x164 net/ax25/ax25_route.c:69
softirqs last disabled at (1214): [<ffff800010461988>] spin_lock_bh include/linux/spinlock.h:368 [inline]
softirqs last disabled at (1214): [<ffff800010461988>] ax25_dev_device_down+0x64/0x67c net/ax25/ax25_dev.c:103
---[ end trace f73cfca4066bb13f ]---
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: 3dea0e7f549e Linux 5.15.186
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=143ccc8c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=fe91feccd8127a59
dashboard link: https://syzkaller.appspot.com/bug?extid=8bedf4107d4cce2e27e2
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: arm64
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e8db6cfea7ea/disk-3dea0e7f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/eeb133c8268e/vmlinux-3dea0e7f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9478525201a1/Image-3dea0e7f.gz.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8bedf4...@syzkaller.appspotmail.com
------------[ cut here ]------------
ODEBUG: assert_init not available (active state 0) object type: timer_list hint: 0x0
WARNING: CPU: 0 PID: 5156 at lib/debugobjects.c:521 debug_print_object+0x148/0x1d4 lib/debugobjects.c:518
Modules linked in:
CPU: 0 PID: 5156 Comm: syz.3.271 Not tainted 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : debug_print_object+0x148/0x1d4 lib/debugobjects.c:518
lr : debug_print_object+0x148/0x1d4 lib/debugobjects.c:518
sp : ffff800020797560
x29: ffff800020797560 x28: ffff8000163e5ce0 x27: 0000000000000002
x26: ffff800014180000 x25: ffff80000837e250 x24: dfff800000000000
x23: 0000000000000000 x22: 0000000000000000 x21: ffff8000117da4e0
x20: ffff800011342ce0 x19: ffff8000117da020 x18: 0000000000000202
x17: 0000000000000002 x16: ffff8000111cf35c x15: 00000000ffffffff
x14: 0000000000ff0100 x13: 0000000000000001 x12: 0000000000080000
x11: 00000000000153b3 x10: ffff800025a19000 x9 : 9542690dbeb0df00
x8 : 9542690dbeb0df00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800020796e58 x4 : ffff80001425f400 x3 : ffff800008505198
x2 : 0000000000000001 x1 : 0000000000000201 x0 : 0000000000000054
Call trace:
debug_print_object+0x148/0x1d4 lib/debugobjects.c:518
debug_object_assert_init+0x24c/0x2c4 lib/debugobjects.c:894
debug_timer_assert_init kernel/time/timer.c:739 [inline]
debug_assert_init kernel/time/timer.c:784 [inline]
del_timer+0x48/0x1e4 kernel/time/timer.c:1224
ax25_ds_del_timer+0x28/0x40 net/ax25/ax25_ds_timer.c:47
ax25_dev_device_down+0x6c/0x67c net/ax25/ax25_dev.c:106
ax25_device_event+0x538/0x590 net/ax25/af_ax25.c:144
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391
call_netdevice_notifiers_info net/core/dev.c:2049 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
call_netdevice_notifiers net/core/dev.c:2075 [inline]
__dev_notify_flags+0x250/0x46c net/core/dev.c:-1
dev_change_flags+0xc8/0x154 net/core/dev.c:8929
dev_ifsioc+0x504/0xef4 net/core/dev_ioctl.c:324
dev_ioctl+0x4d0/0xc94 net/core/dev_ioctl.c:587
sock_do_ioctl+0x18c/0x240 net/socket.c:1154
sock_ioctl+0x5c8/0x87c net/socket.c:1257
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
irq event stamp: 1235
hardirqs last enabled at (1234): [<ffff8000082f8f64>] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:257
hardirqs last disabled at (1235): [<ffff8000111cabbc>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:396
softirqs last enabled at (1212): [<ffff800010467650>] ax25_rt_device_down+0x148/0x164 net/ax25/ax25_route.c:69
softirqs last disabled at (1214): [<ffff800010461988>] spin_lock_bh include/linux/spinlock.h:368 [inline]
softirqs last disabled at (1214): [<ffff800010461988>] ax25_dev_device_down+0x64/0x67c net/ax25/ax25_dev.c:103
---[ end trace f73cfca4066bb13e ]---
==================================================================
BUG: KASAN: slab-out-of-bounds in lockdep_init_map_type+0x4d8/0x6d4 kernel/locking/lockdep.c:4783
Write of size 1 at addr ffff0000db7a24a8 by task syz.3.271/5156
CPU: 0 PID: 5156 Comm: syz.3.271 Tainted: G W 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call trace:
dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
__dump_stack+0x30/0x40 lib/dump_stack.c:88
dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106
print_address_description+0x78/0x30c mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:434 [inline]
kasan_report+0xec/0x15c mm/kasan/report.c:451
__asan_report_store1_noabort+0x44/0x50 mm/kasan/report_generic.c:311
lockdep_init_map_type+0x4d8/0x6d4 kernel/locking/lockdep.c:4783
lockdep_init_map_waits include/linux/lockdep.h:195 [inline]
lockdep_init_map_wait include/linux/lockdep.h:202 [inline]
lockdep_init_map include/linux/lockdep.h:208 [inline]
do_init_timer kernel/time/timer.c:797 [inline]
init_timer_key+0x198/0x418 kernel/time/timer.c:817
timer_fixup_assert_init+0x58/0x78 kernel/time/timer.c:705
debug_object_fixup lib/debugobjects.c:534 [inline]
debug_object_assert_init+0x278/0x2c4 lib/debugobjects.c:895
debug_timer_assert_init kernel/time/timer.c:739 [inline]
debug_assert_init kernel/time/timer.c:784 [inline]
del_timer+0x48/0x1e4 kernel/time/timer.c:1224
ax25_ds_del_timer+0x28/0x40 net/ax25/ax25_ds_timer.c:47
ax25_dev_device_down+0x6c/0x67c net/ax25/ax25_dev.c:106
ax25_device_event+0x538/0x590 net/ax25/af_ax25.c:144
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391
call_netdevice_notifiers_info net/core/dev.c:2049 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
call_netdevice_notifiers net/core/dev.c:2075 [inline]
__dev_notify_flags+0x250/0x46c net/core/dev.c:-1
dev_change_flags+0xc8/0x154 net/core/dev.c:8929
dev_ifsioc+0x504/0xef4 net/core/dev_ioctl.c:324
dev_ioctl+0x4d0/0xc94 net/core/dev_ioctl.c:587
sock_do_ioctl+0x18c/0x240 net/socket.c:1154
sock_ioctl+0x5c8/0x87c net/socket.c:1257
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Allocated by task 4037:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc mm/kasan/common.c:513 [inline]
__kasan_kmalloc+0xb0/0xf0 mm/kasan/common.c:522
kasan_kmalloc include/linux/kasan.h:264 [inline]
__kmalloc_node+0x2bc/0x520 mm/slub.c:4455
kmalloc_array_node include/linux/slab.h:697 [inline]
kcalloc_node include/linux/slab.h:702 [inline]
memcg_alloc_page_obj_cgroups+0x80/0x174 mm/memcontrol.c:2839
memcg_slab_post_alloc_hook mm/slab.h:313 [inline]
slab_post_alloc_hook+0xc0/0x408 mm/slab.h:526
slab_alloc_node mm/slub.c:3220 [inline]
slab_alloc mm/slub.c:3228 [inline]
kmem_cache_alloc+0x1e0/0x3e4 mm/slub.c:3233
__d_alloc+0x3c/0x65c fs/dcache.c:1749
d_alloc_pseudo+0x28/0x8c fs/dcache.c:1878
alloc_file_pseudo+0xcc/0x1dc fs/file_table.c:256
sock_alloc_file+0xb4/0x22c net/socket.c:462
sock_map_fd net/socket.c:486 [inline]
__sys_socket+0x13c/0x18c net/socket.c:1588
__do_sys_socket net/socket.c:1593 [inline]
__se_sys_socket net/socket.c:1591 [inline]
__arm64_sys_socket+0x7c/0x94 net/socket.c:1591
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
The buggy address belongs to the object at ffff0000db7a2400
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 168 bytes inside of
256-byte region [ffff0000db7a2400, ffff0000db7a2500)
The buggy address belongs to the page:
page:000000004caa20af refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11b7a2
head:000000004caa20af order:1 compound_mapcount:0
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 fffffc00033b5c80 0000000300000003 ffff0000c0002480
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff0000db7a2380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff0000db7a2400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000db7a2480: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
^
ffff0000db7a2500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff0000db7a2580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 5156 at lib/refcount.c:28 refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28
Modules linked in:
CPU: 1 PID: 5156 Comm: syz.3.271 Tainted: G B W 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28
lr : refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28
sp : ffff800020797690
x29: ffff800020797690 x28: ffff8000163e5ce0 x27: 1fffe0001b6f4482
x26: ffff80001b1f5000 x25: 1fffe000199a786d x24: dfff800000000000
x23: 0000000000000000 x22: ffff0000db7a24b8 x21: ffff0000ccd3c000
x20: ffff0000db7a24b8 x19: ffff8000165c3000 x18: 0000000000000002
x17: 0000000040000000 x16: ffff8000111cf35c x15: 0000000000000002
x14: 0000000000ff0100 x13: ffffffffffffffff x12: 0000000000080000
x11: 000000000004aa7c x10: ffff800025a19000 x9 : 9542690dbeb0df00
x8 : 9542690dbeb0df00 x7 : 0000000000000000 x6 : ffff80000824599c
x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800008505198
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000026
Call trace:
refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28
__refcount_sub_and_test include/linux/refcount.h:283 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
ax25_dev_put include/net/ax25.h:301 [inline]
ax25_dev_device_down+0x4d4/0x67c net/ax25/ax25_dev.c:119
ax25_device_event+0x538/0x590 net/ax25/af_ax25.c:144
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391
call_netdevice_notifiers_info net/core/dev.c:2049 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
call_netdevice_notifiers net/core/dev.c:2075 [inline]
__dev_notify_flags+0x250/0x46c net/core/dev.c:-1
dev_change_flags+0xc8/0x154 net/core/dev.c:8929
dev_ifsioc+0x504/0xef4 net/core/dev_ioctl.c:324
dev_ioctl+0x4d0/0xc94 net/core/dev_ioctl.c:587
sock_do_ioctl+0x18c/0x240 net/socket.c:1154
sock_ioctl+0x5c8/0x87c net/socket.c:1257
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
irq event stamp: 1243
hardirqs last enabled at (1242): [<ffff8000112a9454>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
hardirqs last enabled at (1242): [<ffff8000112a9454>] _raw_spin_unlock_irqrestore+0xa8/0x14c kernel/locking/spinlock.c:194
hardirqs last disabled at (1243): [<ffff8000112a8f50>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
hardirqs last disabled at (1243): [<ffff8000112a8f50>] _raw_spin_lock_irqsave+0xfc/0x14c kernel/locking/spinlock.c:162
softirqs last enabled at (1212): [<ffff800010467650>] ax25_rt_device_down+0x148/0x164 net/ax25/ax25_route.c:69
softirqs last disabled at (1214): [<ffff800010461988>] spin_lock_bh include/linux/spinlock.h:368 [inline]
softirqs last disabled at (1214): [<ffff800010461988>] ax25_dev_device_down+0x64/0x67c net/ax25/ax25_dev.c:103
---[ end trace f73cfca4066bb13f ]---
---
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syzbot
Oct 12, 2025, 3:13:23 PM (4 days ago) Oct 12
to syzkaller...@googlegroups.com
Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.
Crashes did not happen for a while, no reproducer and no activity.
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