syzbot

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BUG: KASAN: use-after-free in handle_tx+0x1a0/0x5f8 drivers/net/caif/caif_serial.c:236
Read of size 8 at addr ffff0000d47dd018 by task aoe_tx0/2058

CPU: 0 PID: 2058 Comm: aoe_tx0 Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106
 print_address_description+0x88/0x200 mm/kasan/report.c:316
 print_report+0x50/0x68 mm/kasan/report.c:418
 kasan_report+0xa8/0x100 mm/kasan/report.c:522
 __asan_report_load8_noabort+0x2c/0x38 mm/kasan/report_generic.c:351
 handle_tx+0x1a0/0x5f8 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+0x244/0x8e0 net/core/dev.c:3674
 __dev_queue_xmit+0x155c/0x309c net/core/dev.c:4334
 dev_queue_xmit include/linux/netdevice.h:3051 [inline]
 tx+0x9c/0x1c8 drivers/block/aoe/aoenet.c:63
 kthread+0x160/0x330 drivers/block/aoe/aoecmd.c:1241
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:849

Allocated by task 12170:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x80 mm/kasan/common.c:52
 kasan_save_alloc_info+0x28/0x34 mm/kasan/generic.c:505
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0xa0/0xb8 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+0xb8/0x654 drivers/tty/tty_io.c:3089
 tty_init_dev+0x60/0x3e8 drivers/tty/tty_io.c:1408
 tty_open_by_driver drivers/tty/tty_io.c:2081 [inline]
 tty_open+0x6e0/0xb54 drivers/tty/tty_io.c:2128
 chrdev_open+0x26c/0x4f0 fs/char_dev.c:414
 do_dentry_open+0x730/0xfa8 fs/open.c:882
 vfs_open+0x7c/0x90 fs/open.c:1013
 do_open fs/namei.c:3626 [inline]
 path_openat+0x1f48/0x2680 fs/namei.c:3783
 do_filp_open+0x174/0x344 fs/namei.c:3810
 do_sys_openat2+0x128/0x3d8 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+0x120/0x154 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+0x58/0x138 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 4383:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x80 mm/kasan/common.c:52
 kasan_save_free_info+0x3c/0x60 mm/kasan/generic.c:516
 ____kasan_slab_free+0x148/0x1b0 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+0x16c/0x1ec mm/slub.c:1750
 slab_free mm/slub.c:3661 [inline]
 __kmem_cache_free+0xc0/0x224 mm/slub.c:3674
 kfree+0xd0/0x1ac mm/slab_common.c:988
 free_tty_struct drivers/tty/tty_io.c:173 [inline]
 release_one_tty+0x21c/0x238 drivers/tty/tty_io.c:1541
 process_one_work+0x7f4/0x13a8 kernel/workqueue.c:2292
 worker_thread+0x8c8/0xfbc kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:849

Last potentially related work creation:
 kasan_save_stack+0x40/0x70 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xc0/0xdc mm/kasan/generic.c:486
 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:496
 insert_work+0x64/0x37c kernel/workqueue.c:1361
 __queue_work+0xcbc/0x123c 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+0x144/0x1b8 drivers/tty/tty_io.c:1565
 release_tty+0x3e8/0x4a4 drivers/tty/tty_io.c:1601
 tty_release_struct+0xb4/0xd4 drivers/tty/tty_io.c:1700
 tty_release+0xa0c/0x1208 drivers/tty/tty_io.c:1860
 __fput+0x1bc/0x7c0 fs/file_table.c:320
 ____fput+0x20/0x30 fs/file_table.c:348
 task_work_run+0x1ec/0x270 kernel/task_work.c:203
 exit_task_work include/linux/task_work.h:39 [inline]
 do_exit+0x54c/0x19a8 kernel/exit.c:880
 do_group_exit+0x194/0x22c kernel/exit.c:1022
 get_signal+0x11d0/0x1310 kernel/signal.c:2871
 do_signal arch/arm64/kernel/signal.c:1081 [inline]
 do_notify_resume+0x340/0x2b0c arch/arm64/kernel/signal.c:1134
 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]
 el0_svc+0x98/0x138 arch/arm64/kernel/entry-common.c:638
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Second to last potentially related work creation:
 kasan_save_stack+0x40/0x70 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xc0/0xdc mm/kasan/generic.c:486
 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:496
 insert_work+0x64/0x37c kernel/workqueue.c:1361
 __queue_work+0xcbc/0x123c 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]
 bpf_prog_free+0x158/0x170 kernel/bpf/core.c:2627
 bpf_prog_load+0x9f4/0x1284 kernel/bpf/syscall.c:2689
 __sys_bpf+0x47c/0x634 kernel/bpf/syscall.c:5020
 __do_sys_bpf kernel/bpf/syscall.c:5124 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5122 [inline]
 __arm64_sys_bpf+0x80/0x98 kernel/bpf/syscall.c:5122
 __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+0x58/0x138 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 ffff0000d47dd000
 which belongs to the cache kmalloc-cg-2k of size 2048
The buggy address is located 24 bytes inside of
 2048-byte region [ffff0000d47dd000, ffff0000d47dd800)

The buggy address belongs to the physical page:
page:000000002f9457eb refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1147d8
head:000000002f9457eb order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff0000c4513801
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 dead000000000100 dead000000000122 ffff0000c0003380
raw: 0000000000000000 0000000000080008 00000001ffffffff ffff0000c4513801
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000d47dcf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000d47dcf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff0000d47dd000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff0000d47dd080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000d47dd100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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