syzbot has found a reproducer for the following crash on: HEAD commit: 29f3490b net: use indirect call wrappers for skb_copy_data.. git tree: net-next console output: https://syzkaller.appspot.com/x/log.txt?x=12876b91e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=8d5bbd990b8ab319 dashboard link: https://syzkaller.appspot.com/bug?extid=52624bdfbf2746d37d70 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1394bd39e00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10da50ade00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+52624bdfbf2746d37d70@xxxxxxxxxxxxxxxxxxxxxxxxx ------------[ cut here ]------------ WARNING: CPU: 1 PID: 11822 at net/kcm/kcmsock.c:628 kcm_write_msgs+0xfb6/0x1760 net/kcm/kcmsock.c:628 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 11822 Comm: syz-executor408 Not tainted 5.6.0-rc5-syzkaller #0 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+0x188/0x20d lib/dump_stack.c:118 panic+0x2e3/0x75c kernel/panic.c:221 __warn.cold+0x2f/0x35 kernel/panic.c:582 report_bug+0x27b/0x2f0 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:174 [inline] fixup_bug arch/x86/kernel/traps.c:169 [inline] do_error_trap+0x12b/0x220 arch/x86/kernel/traps.c:267 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027 RIP: 0010:kcm_write_msgs+0xfb6/0x1760 net/kcm/kcmsock.c:628 Code: fa 48 c1 ea 03 80 3c 02 00 0f 85 5e 05 00 00 48 8b 44 24 50 45 31 e4 48 8b 74 24 08 48 89 70 10 e9 95 f4 ff ff e8 7a 8a 53 fa <0f> 0b 41 bc ea ff ff ff e9 83 f4 ff ff e8 68 8a 53 fa 0f 0b e9 1c RSP: 0018:ffffc900015e7978 EFLAGS: 00010293 RAX: ffff888085688240 RBX: ffff88808571e800 RCX: ffffffff871e8c3c RDX: 0000000000000000 RSI: ffffffff871e9496 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffff888085688240 R09: fffffbfff185158c R10: fffffbfff185158b R11: ffffffff8c28ac5f R12: 0000000000008000 R13: ffff8880a65b96c0 R14: 00000000000000c0 R15: ffff8880a6fe6d40 kcm_sendmsg+0x1b67/0x2129 net/kcm/kcmsock.c:1034 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 sock_write_iter+0x283/0x3c0 net/socket.c:1004 call_write_iter include/linux/fs.h:1901 [inline] new_sync_write+0x49c/0x700 fs/read_write.c:483 __vfs_write+0xc9/0x100 fs/read_write.c:496 vfs_write+0x262/0x5c0 fs/read_write.c:558 ksys_write+0x1e8/0x250 fs/read_write.c:611 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x446b79 Code: e8 0c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 5b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2e8f3e5d98 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000006dbc48 RCX: 0000000000446b79 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00000000006dbc40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc4c R13: 00000000200003c0 R14: 00000000004aea28 R15: 000000000000d4f5 Kernel Offset: disabled Rebooting in 86400 seconds..
