================================================================== BUG: KASAN: use-after-free in sixpack_close+0x180/0x1f0 drivers/net/hamradio/6pack.c:678 Read of size 8 at addr ffff888078b46c90 by task syz-executor.2/15284 CPU: 0 PID: 15284 Comm: syz-executor.2 Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106 print_address_description+0x65/0x380 mm/kasan/report.c:247 __kasan_report mm/kasan/report.c:433 [inline] kasan_report+0x19a/0x1f0 mm/kasan/report.c:450 sixpack_close+0x180/0x1f0 drivers/net/hamradio/6pack.c:678 tty_ldisc_close drivers/tty/tty_ldisc.c:474 [inline] tty_ldisc_kill drivers/tty/tty_ldisc.c:629 [inline] tty_ldisc_hangup+0x5bc/0x7e0 drivers/tty/tty_ldisc.c:749 __tty_hangup+0x4e5/0x730 drivers/tty/tty_io.c:639 tty_vhangup drivers/tty/tty_io.c:711 [inline] tty_ioctl+0x8ae/0x17d0 drivers/tty/tty_io.c:2745 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f43fffe8ae9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f43fd55e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f44000fbf60 RCX: 00007f43fffe8ae9 RDX: 0000000020000100 RSI: 0000000000005437 RDI: 0000000000000007 RBP: 00007f4400042f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe57f1f9df R14: 00007f43fd55e300 R15: 0000000000022000 Allocated by task 7190: 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+0xdc/0x110 mm/kasan/common.c:513 kasan_kmalloc include/linux/kasan.h:269 [inline] __kmalloc_node+0x28e/0x420 mm/slub.c:4471 kmalloc_node include/linux/slab.h:613 [inline] kvmalloc_node+0x81/0x110 mm/util.c:587 kvmalloc include/linux/slab.h:741 [inline] kvzalloc include/linux/slab.h:749 [inline] alloc_netdev_mqs+0x85/0xc40 net/core/dev.c:10828 sixpack_open+0xe6/0x9e0 drivers/net/hamradio/6pack.c:558 tty_ldisc_open drivers/tty/tty_ldisc.c:449 [inline] tty_set_ldisc+0x530/0x950 drivers/tty/tty_ldisc.c:579 tiocsetd drivers/tty/tty_io.c:2455 [inline] tty_ioctl+0x1477/0x17d0 drivers/tty/tty_io.c:2741 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 15284: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x10d/0x150 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1749 slab_free mm/slub.c:3513 [inline] kfree+0xe1/0x330 mm/slub.c:4561 device_release+0x98/0x1c0 kobject_cleanup+0x1c0/0x280 lib/kobject.c:705 netdev_run_todo+0xb59/0xcf0 net/core/dev.c:10638 unregister_netdev+0x1a0/0x210 net/core/dev.c:11137 sixpack_close+0x169/0x1f0 drivers/net/hamradio/6pack.c:675 tty_ldisc_close drivers/tty/tty_ldisc.c:474 [inline] tty_ldisc_kill drivers/tty/tty_ldisc.c:629 [inline] tty_ldisc_hangup+0x5bc/0x7e0 drivers/tty/tty_ldisc.c:749 __tty_hangup+0x4e5/0x730 drivers/tty/tty_io.c:639 tty_vhangup drivers/tty/tty_io.c:711 [inline] tty_ioctl+0x8ae/0x17d0 drivers/tty/tty_io.c:2745 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xfa/0x130 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:2985 [inline] call_rcu+0x1c4/0xa70 kernel/rcu/tree.c:3065 kvm_recalculate_apic_map+0xf1d/0x1050 arch/x86/kvm/lapic.c:282 kvm_apic_set_state+0x4e9/0x21c0 arch/x86/kvm/lapic.c:2628 kvm_vcpu_ioctl_set_lapic arch/x86/kvm/x86.c:4462 [inline] kvm_arch_vcpu_ioctl+0x122d/0x4e60 arch/x86/kvm/x86.c:5103 kvm_vcpu_ioctl+0x77a/0xe20 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3943 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888078b46000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 3216 bytes inside of 4096-byte region [ffff888078b46000, ffff888078b47000) The buggy address belongs to the page: page:ffffea0001e2d000 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888078b44000 pfn:0x78b40 head:ffffea0001e2d000 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea00006d4608 ffffea0002d4f408 ffff88801184c280 raw: ffff888078b44000 0000000000040003 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2967, ts 17581787586, free_ts 13303400360 prep_new_page mm/page_alloc.c:2418 [inline] get_page_from_freelist+0x729/0x9e0 mm/page_alloc.c:4149 __alloc_pages+0x255/0x580 mm/page_alloc.c:5369 alloc_slab_page mm/slub.c:1793 [inline] allocate_slab+0xcc/0x4d0 mm/slub.c:1930 new_slab mm/slub.c:1993 [inline] ___slab_alloc+0x41e/0xc40 mm/slub.c:3022 __slab_alloc mm/slub.c:3109 [inline] slab_alloc_node mm/slub.c:3200 [inline] __kmalloc_node+0x2ec/0x420 mm/slub.c:4467 kmalloc_node include/linux/slab.h:613 [inline] kvmalloc_node+0x81/0x110 mm/util.c:587 kvmalloc include/linux/slab.h:741 [inline] seq_buf_alloc fs/seq_file.c:38 [inline] seq_read_iter+0x205/0xdc0 fs/seq_file.c:210 call_read_iter include/linux/fs.h:2156 [inline] new_sync_read fs/read_write.c:400 [inline] vfs_read+0xaf9/0xe60 fs/read_write.c:481 ksys_read+0x18f/0x2c0 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1338 [inline] free_pcp_prepare+0xd1c/0xe00 mm/page_alloc.c:1389 free_unref_page_prepare mm/page_alloc.c:3309 [inline] free_unref_page+0x7d/0x580 mm/page_alloc.c:3388 free_contig_range+0xa4/0x100 mm/page_alloc.c:9271 destroy_args+0xfe/0x971 mm/debug_vm_pgtable.c:1016 debug_vm_pgtable+0x449/0x4a1 mm/debug_vm_pgtable.c:1330 do_one_initcall+0xbd/0x2b0 init/main.c:1297 do_initcall_level+0x14a/0x1f5 init/main.c:1370 do_initcalls+0x4b/0x8c init/main.c:1386 kernel_init_freeable+0x43a/0x5c6 init/main.c:1610 kernel_init+0x19/0x2b0 init/main.c:1499 ret_from_fork+0x1f/0x30 Memory state around the buggy address: ffff888078b46b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078b46c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888078b46c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888078b46d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078b46d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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