bisecting fixing commit since b850307b279cbd12ab8c654d1a3dfe55319cc475
building syzkaller on eabcced43245881efa7769d938bcaf795ed48742
testing commit b850307b279cbd12ab8c654d1a3dfe55319cc475 with gcc (GCC) 8.4.1 20210217
kernel signature: d253e77c436a7b5a5f474c04b116b4c3b4ac1d60effaae450818200cd2c841be
run #0: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #1: crashed: KASAN: slab-out-of-bounds Read in __ext4_check_dir_entry
run #2: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #3: crashed: KASAN: slab-out-of-bounds Read in __ext4_check_dir_entry
run #4: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #5: crashed: KASAN: out-of-bounds Read in __ext4_check_dir_entry
run #6: crashed: KASAN: slab-out-of-bounds Read in __ext4_check_dir_entry
run #7: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #8: crashed: KASAN: slab-out-of-bounds Read in __ext4_check_dir_entry
run #9: crashed: KASAN: slab-out-of-bounds Read in __ext4_check_dir_entry
run #10: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #11: crashed: KASAN: slab-out-of-bounds Read in __ext4_check_dir_entry
run #12: crashed: KASAN: use-after-free Read in __ext4_check_dir_entry
run #13: crashed: KASAN: slab-out-of-bounds Read in __ext4_check_dir_entry
run #14: crashed: KASAN: slab-out-of-bounds Read in __ext4_check_dir_entry
run #15: crashed: KASAN: slab-out-of-bounds Read in __ext4_check_dir_entry
run #16: OK
run #17: OK
run #18: OK
run #19: OK
testing current HEAD 96afcb20f36f07683aaa342e592ea8ec76fd1fa6
testing commit 96afcb20f36f07683aaa342e592ea8ec76fd1fa6 with gcc (GCC) 8.4.1 20210217
kernel signature: a2e5e52ad3d503e12fd05a91b9f9a1e2ec114b209bfb6a2e7b3ebd48426c4ece
all runs: crashed: unregister_netdevice: waiting for DEV to become free
revisions tested: 2, total time: 36m24.466660783s (build: 23m27.902137213s, test: 12m19.492096996s)
the crash still happens on HEAD
commit msg: Linux 4.14.233
crash: unregister_netdevice: waiting for DEV to become free
unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1