bisecting fixing commit since c14d30dc9987047b439b03d6e6db7d54d9f7f180 building syzkaller on 5ce135324a84d6de67c913f1b725e3fc5ec39535 testing commit c14d30dc9987047b439b03d6e6db7d54d9f7f180 with gcc (GCC) 8.1.0 kernel signature: b715fb6bdcacbe97e71841a6f35f011cb97c6505174fe391789df7f43e486830 run #0: crashed: WARNING in corrupted run #1: crashed: WARNING in corrupted run #2: crashed: WARNING in ovl_real_fdget_meta run #3: crashed: WARNING in corrupted run #4: crashed: WARNING in ovl_real_fdget_meta run #5: crashed: WARNING in ovl_real_fdget_meta run #6: crashed: WARNING in ovl_real_fdget_meta run #7: crashed: WARNING in ovl_real_fdget_meta run #8: crashed: WARNING in ovl_real_fdget_meta run #9: crashed: WARNING in ovl_real_fdget_meta testing current HEAD a87f96283793d58b042618c689630db264715274 testing commit a87f96283793d58b042618c689630db264715274 with gcc (GCC) 8.1.0 kernel signature: b40d83626fe64a923b8d23f9e890dae57c15f4dd1cbb63be3b9b54154a8df92b run #0: crashed: WARNING in ovl_real_fdget_meta run #1: crashed: WARNING in ovl_real_fdget_meta run #2: crashed: WARNING in ovl_real_fdget_meta run #3: crashed: WARNING in corrupted run #4: crashed: WARNING in corrupted run #5: crashed: WARNING in ovl_real_fdget_meta run #6: crashed: WARNING in ovl_real_fdget_meta run #7: crashed: WARNING in ovl_real_fdget_meta run #8: crashed: WARNING in ovl_real_fdget_meta run #9: crashed: WARNING in ovl_real_fdget_meta revisions tested: 2, total time: 23m10.596878082s (build: 16m34.381430322s, test: 5m59.440779384s) the crash still happens on HEAD commit msg: Linux 4.19.145 crash: WARNING in ovl_real_fdget_meta IPv6: ADDRCONF(NETDEV_UP): macsec0: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth0_to_batadv: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth1_to_batadv: link is not ready batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 7946 at fs/overlayfs/file.c:60 ovl_change_flags fs/overlayfs/file.c:60 [inline] WARNING: CPU: 0 PID: 7946 at fs/overlayfs/file.c:60 ovl_real_fdget_meta.cold.3+0xc/0x18 fs/overlayfs/file.c:111 Kernel panic - not syncing: panic_on_warn set ... batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! CPU: 0 PID: 7946 Comm: syz-executor.2 Not tainted 4.19.145-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+0x17c/0x22a lib/dump_stack.c:118 panic+0x1cd/0x375 kernel/panic.c:186 __warn.cold.7+0x1b/0x3e kernel/panic.c:541 report_bug+0x1a4/0x200 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x200/0x350 arch/x86/kernel/traps.c:296 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038 RIP: 0010:ovl_change_flags fs/overlayfs/file.c:60 [inline] RIP: 0010:ovl_real_fdget_meta.cold.3+0xc/0x18 fs/overlayfs/file.c:111 Code: ff e9 87 fe ff ff 4c 89 8d 70 ff ff ff e8 59 dd 50 ff 4c 8b 8d 70 ff ff ff e9 93 fe ff ff 48 c7 c7 e0 b9 52 87 e8 e1 7d 0d ff <0f> 0b b8 fb ff ff ff e9 42 cd ff ff 48 c7 c7 e0 b9 52 87 e8 c9 7d RSP: 0018:ffff8880a91573c0 EFLAGS: 00010282 RAX: 0000000000000024 RBX: ffff8880a9157430 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff876785e0 RDI: ffffffff8a1a5a60 RBP: ffff8880a91573f0 R08: ffffed1015d45081 R09: ffffed1015d45080 R10: ffffed1015d45080 R11: ffff8880aea28407 R12: 000000000000a000 R13: ffff8880a54f1a00 R14: ffff8880a54f1a78 R15: ffff8880758fb530 ovl_real_fdget fs/overlayfs/file.c:118 [inline] ovl_read_iter+0xf4/0x2b3 fs/overlayfs/file.c:243 call_read_iter include/linux/fs.h:1815 [inline] do_iter_readv_writev+0x3ed/0x960 fs/read_write.c:679 do_iter_read+0x1e0/0x560 fs/read_write.c:923 vfs_readv+0xc9/0x130 fs/read_write.c:987 kernel_readv fs/splice.c:362 [inline] default_file_splice_read+0x411/0x910 fs/splice.c:417 overlayfs: failed to resolve './file1': -2 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! do_splice_to+0xe3/0x120 fs/splice.c:881 splice_direct_to_actor+0x296/0x870 fs/splice.c:959 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 do_splice_direct+0x14c/0x270 fs/splice.c:1068 do_sendfile+0x481/0xcf0 fs/read_write.c:1447 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x100/0x120 fs/read_write.c:1494 __x64_sys_sendfile64+0x92/0xf0 fs/read_write.c:1494 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45d239 Code: 5d b4 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f713c319c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000026bc0 RCX: 000000000045d239 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003 RBP: 000000000118cf88 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000bd96 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffd1cb0435f R14: 00007f713c31a9c0 R15: 000000000118cf4c Kernel Offset: disabled Rebooting in 86400 seconds..