================================================================== BUG: KASAN: use-after-free in ax25_fillin_cb_from_dev net/ax25/af_ax25.c:468 [inline] BUG: KASAN: use-after-free in ax25_fillin_cb+0x460/0x660 net/ax25/af_ax25.c:495 Read of size 4 at addr ffff88802a98a638 by task syz.0.1435/11291 CPU: 0 PID: 11291 Comm: syz.0.1435 Not tainted 5.15.180-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 ax25_fillin_cb_from_dev net/ax25/af_ax25.c:468 [inline] ax25_fillin_cb+0x460/0x660 net/ax25/af_ax25.c:495 ax25_setsockopt+0xab7/0xe70 net/ax25/af_ax25.c:690 __sys_setsockopt+0x57e/0x990 net/socket.c:2203 __do_sys_setsockopt net/socket.c:2214 [inline] __se_sys_setsockopt net/socket.c:2211 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2211 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f63c0c40169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f63beaa9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f63c0e58fa0 RCX: 00007f63c0c40169 RDX: 0000000000000019 RSI: 0000000000000101 RDI: 0000000000000007 RBP: 00007f63c0cc1990 R08: 0000000000000010 R09: 0000000000000000 R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f63c0e58fa0 R15: 00007ffe6bcb5fb8 Allocated by task 10631: 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+0xba/0xf0 mm/kasan/common.c:513 kasan_kmalloc include/linux/kasan.h:264 [inline] kmem_cache_alloc_trace+0x143/0x290 mm/slub.c:3247 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:735 [inline] ax25_dev_device_up+0x51/0x5a0 net/ax25/ax25_dev.c:55 ax25_device_event+0x4a0/0x510 net/ax25/af_ax25.c:139 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:391 __dev_notify_flags+0x1fd/0x3f0 net/core/dev.c:-1 dev_change_flags+0xe7/0x190 net/core/dev.c:8928 dev_ifsioc+0x147/0x10c0 net/core/dev_ioctl.c:324 dev_ioctl+0x504/0xf60 net/core/dev_ioctl.c:587 sock_do_ioctl+0x34f/0x5a0 net/socket.c:1154 sock_ioctl+0x484/0x770 net/socket.c:1257 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 11258: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kfree+0xf1/0x270 mm/slub.c:4559 ax25_dev_put include/net/ax25.h:302 [inline] ax25_release+0x3b3/0x840 net/ax25/af_ax25.c:1062 __sock_release net/socket.c:649 [inline] sock_close+0xcd/0x230 net/socket.c:1336 __fput+0x3fe/0x8e0 fs/file_table.c:311 task_work_run+0x129/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Last potentially related work creation: kasan_save_stack+0x36/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348 insert_work+0x54/0x3e0 kernel/workqueue.c:1366 __queue_work+0x963/0xd00 kernel/workqueue.c:1532 queue_work_on+0x14b/0x250 kernel/workqueue.c:1559 queue_work include/linux/workqueue.h:512 [inline] loop_queue_work drivers/block/loop.c:1067 [inline] loop_queue_rq+0x9ed/0xae0 drivers/block/loop.c:2201 blk_mq_dispatch_rq_list+0xaca/0x1f30 block/blk-mq.c:1386 __blk_mq_sched_dispatch_requests+0x382/0x490 block/blk-mq-sched.c:333 blk_mq_sched_dispatch_requests+0xf3/0x1b0 block/blk-mq-sched.c:366 __blk_mq_run_hw_queue+0x11a/0x1b0 block/blk-mq.c:1511 __blk_mq_delay_run_hw_queue+0x199/0x640 block/blk-mq.c:1588 blk_mq_run_hw_queue+0x1d5/0x3c0 block/blk-mq.c:1641 blk_mq_run_hw_queues+0x33c/0x4e0 block/blk-mq.c:1703 blk_mq_requeue_work+0x73d/0x780 block/blk-mq.c:807 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Second to last potentially related work creation: kasan_save_stack+0x36/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348 insert_work+0x54/0x3e0 kernel/workqueue.c:1366 __queue_work+0x963/0xd00 kernel/workqueue.c:1532 queue_work_on+0x14b/0x250 kernel/workqueue.c:1559 queue_work include/linux/workqueue.h:512 [inline] loop_queue_work drivers/block/loop.c:1067 [inline] loop_queue_rq+0x9ed/0xae0 drivers/block/loop.c:2201 __blk_mq_issue_directly block/blk-mq.c:2014 [inline] __blk_mq_try_issue_directly+0x4be/0x860 block/blk-mq.c:2070 blk_mq_try_issue_directly+0x116/0x370 block/blk-mq.c:2101 blk_mq_submit_bio+0x11bb/0x1c40 block/blk-mq.c:2323 __submit_bio+0x813/0x850 block/blk-core.c:917 __submit_bio_noacct_mq block/blk-core.c:997 [inline] submit_bio_noacct+0x955/0xb30 block/blk-core.c:1027 submit_bio+0x2dd/0x560 block/blk-core.c:1089 submit_bh+0x21/0x30 fs/buffer.c:3062 ext4_read_block_bitmap_nowait+0x6f9/0x970 fs/ext4/balloc.c:542 ext4_read_block_bitmap+0x1c/0x80 fs/ext4/balloc.c:588 ext4_mb_clear_bb fs/ext4/mballoc.c:6040 [inline] ext4_free_blocks+0xff3/0x2e90 fs/ext4/mballoc.c:6286 ext4_remove_blocks fs/ext4/extents.c:2523 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2689 [inline] ext4_ext_remove_space+0x24da/0x4db0 fs/ext4/extents.c:2937 ext4_ext_truncate+0x191/0x250 fs/ext4/extents.c:4471 ext4_truncate+0x9fd/0x1130 fs/ext4/inode.c:4249 ext4_evict_inode+0xba1/0x1100 fs/ext4/inode.c:289 evict+0x529/0x930 fs/inode.c:647 ext4_orphan_cleanup+0x9d9/0x1240 fs/ext4/orphan.c:474 ext4_fill_super+0x98de/0xa110 fs/ext4/super.c:4975 mount_bdev+0x2c9/0x3f0 fs/super.c:1400 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x2ba/0xb40 fs/namespace.c:3012 do_mount fs/namespace.c:3355 [inline] __do_sys_mount fs/namespace.c:3563 [inline] __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3540 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff88802a98a600 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 56 bytes inside of 192-byte region [ffff88802a98a600, ffff88802a98a6c0) The buggy address belongs to the page: page:ffffea0000aa6280 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2a98a flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 dead000000000100 dead000000000122 ffff888017441a00 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 16243785504, free_ts 15415056497 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192 __alloc_pages+0x272/0x700 mm/page_alloc.c:5466 alloc_page_interleave+0x22/0x1c0 mm/mempolicy.c:2031 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc_trace+0x1a0/0x290 mm/slub.c:3245 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:735 [inline] call_usermodehelper_setup+0x8a/0x260 kernel/umh.c:365 kobject_uevent_env+0x681/0x8d0 lib/kobject_uevent.c:629 rx_queue_add_kobject net/core/net-sysfs.c:1070 [inline] net_rx_queue_update_kobjects+0x215/0x480 net/core/net-sysfs.c:1110 register_queue_kobjects net/core/net-sysfs.c:1767 [inline] netdev_register_kobject+0x222/0x310 net/core/net-sysfs.c:2018 register_netdevice+0xfe7/0x16a0 net/core/dev.c:10396 register_netdev+0x37/0x50 net/core/dev.c:10520 rose_proto_init+0x19c/0x7c0 net/rose/af_rose.c:1584 do_one_initcall+0x22b/0x7a0 init/main.c:1302 do_initcall_level+0x157/0x210 init/main.c:1375 do_initcalls+0x49/0x90 init/main.c:1391 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433 release_pages+0x1bb9/0x1f40 mm/swap.c:963 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu mm/mmu_gather.c:247 [inline] tlb_finish_mmu+0x177/0x320 mm/mmu_gather.c:338 exit_mmap+0x3cd/0x620 mm/mmap.c:3206 __mmput+0x112/0x3b0 kernel/fork.c:1127 free_bprm+0x135/0x2f0 fs/exec.c:1494 kernel_execve+0x3bd/0x9b0 fs/exec.c:2015 call_usermodehelper_exec_async+0x22f/0x370 kernel/umh.c:112 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Memory state around the buggy address: ffff88802a98a500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88802a98a580: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802a98a600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802a98a680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88802a98a700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================