skbuff: bad partial csum: csum=55150/36832 headroom=64 headlen=64997 ================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] BUG: KASAN: use-after-free in refcount_read include/linux/refcount.h:43 [inline] BUG: KASAN: use-after-free in skb_unref include/linux/skbuff.h:1016 [inline] BUG: KASAN: use-after-free in kfree_skb+0x38/0x3c0 net/core/skbuff.c:693 Read of size 4 at addr ffff88806ce11354 by task syz-executor.1/14853 CPU: 1 PID: 14853 Comm: syz-executor.1 Not tainted 5.2.0+ #42 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482 kasan_report+0x12/0x20 mm/kasan/common.c:612 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192 __kasan_check_read+0x11/0x20 mm/kasan/common.c:92 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] refcount_read include/linux/refcount.h:43 [inline] skb_unref include/linux/skbuff.h:1016 [inline] kfree_skb+0x38/0x3c0 net/core/skbuff.c:693 tun_get_user+0x2195/0x3f90 drivers/net/tun.c:1871 tun_chr_write_iter+0xbd/0x156 drivers/net/tun.c:2017 call_write_iter include/linux/fs.h:1870 [inline] new_sync_write+0x4d3/0x770 fs/read_write.c:483 __vfs_write+0xe1/0x110 fs/read_write.c:496 vfs_write+0x20c/0x580 fs/read_write.c:558 ksys_write+0x14f/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459829 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f332076dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459829 RDX: 000000000000fdef RSI: 0000000020000500 RDI: 0000000000000003 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f332076e6d4 R13: 00000000004c991e R14: 00000000004e0ed8 R15: 00000000ffffffff Allocated by task 14853: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:487 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:460 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:495 slab_post_alloc_hook mm/slab.h:520 [inline] slab_alloc mm/slab.c:3319 [inline] kmem_cache_alloc+0x121/0x710 mm/slab.c:3483 __build_skb+0x26/0x70 net/core/skbuff.c:310 __napi_alloc_skb+0x1d2/0x300 net/core/skbuff.c:523 napi_alloc_skb include/linux/skbuff.h:2805 [inline] napi_get_frags net/core/dev.c:5735 [inline] napi_get_frags+0x65/0x140 net/core/dev.c:5730 tun_napi_alloc_frags drivers/net/tun.c:1473 [inline] tun_get_user+0x16bd/0x3f90 drivers/net/tun.c:1831 tun_chr_write_iter+0xbd/0x156 drivers/net/tun.c:2017 call_write_iter include/linux/fs.h:1870 [inline] new_sync_write+0x4d3/0x770 fs/read_write.c:483 __vfs_write+0xe1/0x110 fs/read_write.c:496 vfs_write+0x20c/0x580 fs/read_write.c:558 ksys_write+0x14f/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 14848: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:449 kasan_slab_free+0xe/0x10 mm/kasan/common.c:457 __cache_free mm/slab.c:3425 [inline] kmem_cache_free+0x86/0x320 mm/slab.c:3693 kfree_skbmem net/core/skbuff.c:623 [inline] kfree_skbmem+0xc5/0x150 net/core/skbuff.c:617 __kfree_skb net/core/skbuff.c:680 [inline] kfree_skb net/core/skbuff.c:697 [inline] kfree_skb+0x109/0x3c0 net/core/skbuff.c:691 napi_free_frags include/linux/netdevice.h:3630 [inline] netif_napi_del+0x182/0x360 net/core/dev.c:6321 tun_napi_del drivers/net/tun.c:331 [inline] tun_detach_all+0x507/0x840 drivers/net/tun.c:771 tun_net_uninit+0x16/0x20 drivers/net/tun.c:1010 rollback_registered_many+0xab8/0xfc0 net/core/dev.c:8210 rollback_registered+0x109/0x1d0 net/core/dev.c:8238 register_netdevice+0xa85/0xf10 net/core/dev.c:8755 tun_set_iff drivers/net/tun.c:2833 [inline] __tun_chr_ioctl+0x2d95/0x3ef0 drivers/net/tun.c:3066 tun_chr_ioctl+0x2b/0x40 drivers/net/tun.c:3346 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88806ce11280 which belongs to the cache skbuff_head_cache of size 224 The buggy address is located 212 bytes inside of 224-byte region [ffff88806ce11280, ffff88806ce11360) The buggy address belongs to the page: page:ffffea0001b38440 refcount:1 mapcount:0 mapping:ffff8880a99aa8c0 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea0001a416c8 ffffea0002a6dac8 ffff8880a99aa8c0 raw: 0000000000000000 ffff88806ce11000 000000010000000c 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88806ce11200: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ffff88806ce11280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806ce11300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff88806ce11380: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff88806ce11400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================