==================================================================
BUG: KASAN: use-after-free in ax25_addr_ax25dev+0x5c/0x19c net/ax25/ax25_dev.c:38
Read of size 8 at addr ffff0000cfda4e08 by task syz.1.874/7063
CPU: 1 PID: 7063 Comm: syz.1.874 Not tainted 5.15.177-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call trace:
dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
print_address_description+0x7c/0x3f0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:434 [inline]
kasan_report+0x174/0x1e4 mm/kasan/report.c:451
__asan_report_load8_noabort+0x44/0x50 mm/kasan/report_generic.c:309
ax25_addr_ax25dev+0x5c/0x19c net/ax25/ax25_dev.c:38
ax25_rt_add net/ax25/ax25_route.c:81 [inline]
ax25_rt_ioctl+0x738/0x1640 net/ax25/ax25_route.c:239
ax25_ioctl+0x8f4/0x1fb4 net/ax25/af_ax25.c:1819
sock_do_ioctl+0x134/0x2dc net/socket.c:1140
sock_ioctl+0x4f0/0x8ac 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+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Allocated by task 6328:
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+0xbc/0xfc mm/kasan/common.c:513
__kasan_kmalloc+0x10/0x1c mm/kasan/common.c:522
kasan_kmalloc include/linux/kasan.h:264 [inline]
kmem_cache_alloc_trace+0x27c/0x47c mm/slub.c:3247
kmalloc include/linux/slab.h:591 [inline]
kzalloc include/linux/slab.h:721 [inline]
ax25_dev_device_up+0x5c/0x548 net/ax25/ax25_dev.c:55
ax25_device_event+0x500/0x58c net/ax25/af_ax25.c:139
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391
__dev_notify_flags+0x2ac/0x534
dev_change_flags+0xc8/0x154 net/core/dev.c:8897
dev_ifsioc+0x140/0xfe4 net/core/dev_ioctl.c:324
dev_ioctl+0x4e0/0xd3c net/core/dev_ioctl.c:587
sock_do_ioctl+0x1dc/0x2dc net/socket.c:1154
sock_ioctl+0x4f0/0x8ac 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+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Freed by task 6908:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4c/0x84 mm/kasan/common.c:46
kasan_set_free_info+0x28/0x4c mm/kasan/generic.c:360
____kasan_slab_free+0x118/0x164 mm/kasan/common.c:366
__kasan_slab_free+0x18/0x28 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1705 [inline]
slab_free_freelist_hook+0x128/0x1ec mm/slub.c:1731
slab_free mm/slub.c:3499 [inline]
kfree+0x178/0x410 mm/slub.c:4559
ax25_dev_put include/net/ax25.h:302 [inline]
ax25_release+0x57c/0x82c net/ax25/af_ax25.c:1062
__sock_release net/socket.c:649 [inline]
sock_close+0xb8/0x1fc net/socket.c:1336
__fput+0x1c4/0x800 fs/file_table.c:280
____fput+0x20/0x30 fs/file_table.c:308
task_work_run+0x130/0x1e4 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
do_notify_resume+0x262c/0x32b8 arch/arm64/kernel/signal.c:946
prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline]
exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline]
el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:609
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Last potentially related work creation:
kasan_save_stack+0x38/0x68 mm/kasan/common.c:38
kasan_record_aux_stack+0xd4/0x11c mm/kasan/generic.c:348
insert_work+0x64/0x394 kernel/workqueue.c:1366
__queue_work+0xb84/0x114c kernel/workqueue.c:1532
queue_work_on+0xc4/0x17c kernel/workqueue.c:1559
queue_work include/linux/workqueue.h:512 [inline]
loop_queue_work drivers/block/loop.c:1067 [inline]
loop_queue_rq+0x9a8/0xb20 drivers/block/loop.c:2201
blk_mq_dispatch_rq_list+0x890/0x14ac block/blk-mq.c:1386
__blk_mq_sched_dispatch_requests+0x2fc/0x420 block/blk-mq-sched.c:333
blk_mq_sched_dispatch_requests+0xc4/0x174 block/blk-mq-sched.c:366
__blk_mq_run_hw_queue block/blk-mq.c:1511 [inline]
__blk_mq_delay_run_hw_queue+0x334/0x714 block/blk-mq.c:1588
blk_mq_run_hw_queue+0x198/0x324 block/blk-mq.c:1641
blk_mq_run_hw_queues+0x2f0/0x404 block/blk-mq.c:1703
blk_mq_requeue_work+0x5d0/0x620 block/blk-mq.c:807
process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
worker_thread+0x910/0x1034 kernel/workqueue.c:2457
kthread+0x37c/0x45c kernel/kthread.c:334
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
Second to last potentially related work creation:
kasan_save_stack+0x38/0x68 mm/kasan/common.c:38
kasan_record_aux_stack+0xd4/0x11c mm/kasan/generic.c:348
insert_work+0x64/0x394 kernel/workqueue.c:1366
__queue_work+0xb84/0x114c kernel/workqueue.c:1532
queue_work_on+0xc4/0x17c kernel/workqueue.c:1559
queue_work include/linux/workqueue.h:512 [inline]
loop_queue_work drivers/block/loop.c:1067 [inline]
loop_queue_rq+0x9a8/0xb20 drivers/block/loop.c:2201
__blk_mq_issue_directly block/blk-mq.c:2014 [inline]
__blk_mq_try_issue_directly+0x404/0x6dc block/blk-mq.c:2070
blk_mq_request_issue_directly block/blk-mq.c:2118 [inline]
blk_mq_try_issue_list_directly+0x1e0/0x55c block/blk-mq.c:2136
blk_mq_sched_insert_requests+0x354/0x83c block/blk-mq-sched.c:512
blk_mq_flush_plug_list+0x570/0x850 block/blk-mq.c:1971
blk_flush_plug_list+0x37c/0x3d0 block/blk-core.c:1734
blk_finish_plug+0x68/0x90 block/blk-core.c:1751
generic_writepages+0x104/0x164 mm/page-writeback.c:2369
blkdev_writepages+0x28/0x38 block/fops.c:389
do_writepages+0x39c/0x5ec mm/page-writeback.c:2386
filemap_fdatawrite_wbc+0x1c8/0x228 mm/filemap.c:400
__filemap_fdatawrite_range mm/filemap.c:433 [inline]
__filemap_fdatawrite mm/filemap.c:439 [inline]
filemap_flush+0x100/0x148 mm/filemap.c:466
sync_blockdev_nowait+0x64/0x80 block/bdev.c:191
sync_filesystem+0x13c/0x218 fs/sync.c:60
generic_shutdown_super+0x70/0x2f0 fs/super.c:448
kill_block_super+0x70/0xdc fs/super.c:1427
deactivate_locked_super+0xb8/0x13c fs/super.c:335
deactivate_super+0x108/0x128 fs/super.c:366
cleanup_mnt+0x3c0/0x474 fs/namespace.c:1143
__cleanup_mnt+0x20/0x30 fs/namespace.c:1150
task_work_run+0x130/0x1e4 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
do_notify_resume+0x262c/0x32b8 arch/arm64/kernel/signal.c:946
prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline]
exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline]
el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:609
el0t_64_sync_handler+0x84/0xe4 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 ffff0000cfda4e00
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 8 bytes inside of
256-byte region [ffff0000cfda4e00, ffff0000cfda4f00)
The buggy address belongs to the page:
page:0000000025234907 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000cfda5400 pfn:0x10fda4
head:0000000025234907 order:1 compound_mapcount:0
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 fffffc0003070e08 fffffc000340c588 ffff0000c0002480
raw: ffff0000cfda5400 000000000010000f 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff0000cfda4d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff0000cfda4d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff0000cfda4e00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff0000cfda4e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff0000cfda4f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
Unable to handle kernel paging request at virtual address 0027808de00003d0
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
[0027808de00003d0] address between user and kernel address ranges
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 7063 Comm: syz.1.874 Tainted: G B 5.15.177-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : ax25_addr_ax25dev+0x68/0x19c net/ax25/ax25_dev.c:38
lr : ax25_addr_ax25dev+0x5c/0x19c net/ax25/ax25_dev.c:38
sp : ffff800020107620
x29: ffff800020107620 x28: dfff800000000000 x27: ffff700004020ed4
x26: ffff80002010770e x25: 00000000200000c0 x24: ffff800020107820
x23: dfff800000000000 x22: a140046f00001e84 x21: 0000000000000000
x20: ffff0000cfda4e00 x19: ffff800020107700 x18: 0000000000000203
x17: 0000000000000002 x16: ffff80000824ec08 x15: 00000000ffffffff
x14: ffff0000ec4bb680 x13: 0000000000000001 x12: 0000000000080000
x11: 0000000000032eab x10: ffff80002118c000 x9 : 0000000000000000
x8 : 1428008de00003d0 x7 : 0000000000000000 x6 : 0000000000000001
x5 : ffff800020106cb8 x4 : 0000000000000000 x3 : ffff80000819c3f0
x2 : 0000000000000001 x1 : 0000000000000001 x0 : 0000000000000001
Call trace:
ax25_addr_ax25dev+0x68/0x19c net/ax25/ax25_dev.c:38
ax25_rt_add net/ax25/ax25_route.c:81 [inline]
ax25_rt_ioctl+0x738/0x1640 net/ax25/ax25_route.c:239
ax25_ioctl+0x8f4/0x1fb4 net/ax25/af_ax25.c:1819
sock_do_ioctl+0x134/0x2dc net/socket.c:1140
sock_ioctl+0x4f0/0x8ac 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+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: 97c55dae f94002c8 910e2116 d343fec8 (38776908)
---[ end trace 34badd5e4f4177c4 ]---
----------------
Code disassembly (best guess):
0: 97c55dae bl 0xffffffffff1576b8
4: f94002c8 ldr x8, [x22]
8: 910e2116 add x22, x8, #0x388
c: d343fec8 lsr x8, x22, #3
* 10: 38776908 ldrb w8, [x8, x23] <-- trapping instruction