================================================================== BUG: KASAN: use-after-free in napi_frags_skb net/core/dev.c:5833 [inline] BUG: KASAN: use-after-free in napi_gro_frags+0xc6f/0xd10 net/core/dev.c:5841 Read of size 2 at addr ffff88808af6840c by task syz-executor842/8949 CPU: 1 PID: 8949 Comm: syz-executor842 Not tainted 5.2.0-rc2+ #14 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+0x7c/0x20d mm/kasan/report.c:188 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/generic_report.c:142 napi_frags_skb net/core/dev.c:5833 [inline] napi_gro_frags+0xc6f/0xd10 net/core/dev.c:5841 tun_get_user+0x2f3c/0x3ff0 drivers/net/tun.c:1991 tun_chr_write_iter+0xbd/0x156 drivers/net/tun.c:2037 call_write_iter include/linux/fs.h:1872 [inline] do_iter_readv_writev+0x5f8/0x8f0 fs/read_write.c:693 do_iter_write fs/read_write.c:970 [inline] do_iter_write+0x184/0x610 fs/read_write.c:951 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1015 do_writev+0x15b/0x330 fs/read_write.c:1058 __do_sys_writev fs/read_write.c:1131 [inline] __se_sys_writev fs/read_write.c:1128 [inline] __x64_sys_writev+0x75/0xb0 fs/read_write.c:1128 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441cd0 Code: 05 48 3d 01 f0 ff ff 0f 83 9d 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 83 3d 41 93 29 00 00 75 14 b8 14 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 74 09 fc ff c3 48 83 ec 08 e8 ba 2b 00 00 RSP: 002b:00007ffc3b177348 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007ffc3b177370 RCX: 0000000000441cd0 RDX: 0000000000000003 RSI: 00007ffc3b177390 RDI: 00000000000000f0 RBP: 00007ffc3b177390 R08: 00007ffc3b1773c0 R09: 0000000000000003 R10: 0000000000000d77 R11: 0000000000000246 R12: 0000000000011ee2 R13: 0000000000402b60 R14: 0000000000000000 R15: 0000000000000000 The buggy address belongs to the page: page:ffffea00022bda00 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 flags: 0x1fffc0000000000() raw: 01fffc0000000000 ffffea000230c408 ffff88812fffc878 0000000000000000 raw: 0000000000000000 0000000000000003 00000000ffffff7f 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808af68300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88808af68380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88808af68400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88808af68480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88808af68500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================