syzbot

==================================================================
BUG: KASAN: use-after-free in handle_tx+0x1ac/0x5f8 drivers/net/caif/caif_serial.c:236
Read of size 8 at addr ffff0000dc208018 by task aoe_tx0/2061

CPU: 0 PID: 2061 Comm: aoe_tx0 Not tainted 6.1.131-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_load8_noabort+0x2c/0x38 mm/kasan/report_generic.c:351
 handle_tx+0x1ac/0x5f8 drivers/net/caif/caif_serial.c:236
 caif_xmit+0x108/0x150 drivers/net/caif/caif_serial.c:282
 __netdev_start_xmit include/linux/netdevice.h:4896 [inline]
 netdev_start_xmit include/linux/netdevice.h:4910 [inline]
 xmit_one net/core/dev.c:3658 [inline]
 dev_hard_start_xmit+0x25c/0x9a4 net/core/dev.c:3674
 __dev_queue_xmit+0x161c/0x34d4 net/core/dev.c:4334
 dev_queue_xmit include/linux/netdevice.h:3051 [inline]
 tx+0x9c/0x1c8 drivers/block/aoe/aoenet.c:63
 kthread+0x1ac/0x374 drivers/block/aoe/aoecmd.c:1237
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864

Allocated by task 5909:
 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]
 kzalloc include/linux/slab.h:699 [inline]
 alloc_tty_struct+0xb8/0x68c drivers/tty/tty_io.c:3089
 tty_init_dev+0x60/0x3ec drivers/tty/tty_io.c:1408
 tty_open_by_driver drivers/tty/tty_io.c:2081 [inline]
 tty_open+0x804/0xc20 drivers/tty/tty_io.c:2128
 chrdev_open+0x3e8/0x4fc fs/char_dev.c:414
 do_dentry_open+0x734/0xfa0 fs/open.c:882
 vfs_open+0x7c/0x90 fs/open.c:1013
 do_open fs/namei.c:3626 [inline]
 path_openat+0x1e14/0x2548 fs/namei.c:3783
 do_filp_open+0x1bc/0x3cc fs/namei.c:3810
 do_sys_openat2+0x128/0x3e0 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __arm64_sys_openat+0x1f0/0x240 fs/open.c:1345
 __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 4330:
 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
 free_tty_struct drivers/tty/tty_io.c:173 [inline]
 release_one_tty+0x224/0x244 drivers/tty/tty_io.c:1541
 process_one_work+0x804/0x1484 kernel/workqueue.c:2292
 worker_thread+0x8e4/0xfec kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864

Last potentially related work creation:
 kasan_save_stack+0x40/0x70 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xcc/0xe8 mm/kasan/generic.c:486
 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:496
 insert_work+0x64/0x384 kernel/workqueue.c:1361
 __queue_work+0xd48/0x136c kernel/workqueue.c:1520
 queue_work_on+0xc0/0x16c kernel/workqueue.c:1548
 queue_work include/linux/workqueue.h:512 [inline]
 schedule_work include/linux/workqueue.h:573 [inline]
 queue_release_one_tty drivers/tty/tty_io.c:1552 [inline]
 kref_put include/linux/kref.h:65 [inline]
 tty_kref_put+0x14c/0x1c0 drivers/tty/tty_io.c:1565
 release_tty+0x3f0/0x4ac drivers/tty/tty_io.c:1601
 tty_release_struct+0xb4/0xd4 drivers/tty/tty_io.c:1700
 tty_release+0xb64/0x1014 drivers/tty/tty_io.c:1860
 __fput+0x1c8/0x7c8 fs/file_table.c:320
 ____fput+0x20/0x30 fs/file_table.c:348
 task_work_run+0x240/0x2f0 kernel/task_work.c:203
 exit_task_work include/linux/task_work.h:39 [inline]
 do_exit+0x550/0x1a84 kernel/exit.c:871
 do_group_exit+0x194/0x22c kernel/exit.c:1021
 get_signal+0x143c/0x1528 kernel/signal.c:2871
 do_signal arch/arm64/kernel/signal.c:1076 [inline]
 do_notify_resume+0x388/0x2cb8 arch/arm64/kernel/signal.c:1129
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
 asm_exit_to_user_mode+0x70/0x84 arch/arm64/kernel/entry-common.c:149
 ret_from_fork+0x1c/0x20 arch/arm64/kernel/entry.S:867

Second to last potentially related work creation:
 kasan_save_stack+0x40/0x70 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xcc/0xe8 mm/kasan/generic.c:486
 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:496
 kvfree_call_rcu+0xb4/0x714 kernel/rcu/tree.c:3401
 drop_sysctl_table+0x274/0x3a0 fs/proc/proc_sysctl.c:1727
 unregister_sysctl_table+0x90/0x12c fs/proc/proc_sysctl.c:1765
 unregister_net_sysctl_table+0x20/0x30 net/sysctl_net.c:174
 __addrconf_sysctl_unregister net/ipv6/addrconf.c:7167 [inline]
 addrconf_sysctl_unregister net/ipv6/addrconf.c:7195 [inline]
 addrconf_notify+0x294/0xcb4 net/ipv6/addrconf.c:3730
 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]
 dev_change_name+0x524/0x7e0 net/core/dev.c:1282
 do_setlink+0x8e8/0x3470 net/core/rtnetlink.c:2810
 __rtnl_newlink net/core/rtnetlink.c:3605 [inline]
 rtnl_newlink+0x13cc/0x1b14 net/core/rtnetlink.c:3652
 rtnetlink_rcv_msg+0x734/0xd9c net/core/rtnetlink.c:6150
 netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2493
 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6168
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0x65c/0x898 net/netlink/af_netlink.c:1337
 netlink_sendmsg+0x844/0xb28 net/netlink/af_netlink.c:1859
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 __sys_sendto+0x3b8/0x508 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+0x58/0x168 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 ffff0000dc208000
 which belongs to the cache kmalloc-cg-2k of size 2048
The buggy address is located 24 bytes inside of
 2048-byte region [ffff0000dc208000, ffff0000dc208800)

The buggy address belongs to the physical page:
page:00000000151e7ed6 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11c208
head:00000000151e7ed6 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff0000f125d801
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 0000000000000000 dead000000000001 ffff0000c0003380
raw: 0000000000000000 0000000000080008 00000001ffffffff ffff0000f125d801
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000dc207f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000dc207f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff0000dc208000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff0000dc208080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000dc208100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================