bisecting fixing commit since 43598c571e7ed29e4c81e35b4a870fe6b9f8d58e
building syzkaller on 4f7e1d0f5e1c44e2298738f690dde25c486cc65a
testing commit 43598c571e7ed29e4c81e35b4a870fe6b9f8d58e with gcc (GCC) 8.4.1 20210217
kernel signature: 069b06a76bfdbb946fe810860759b6415bb4185c21ea44780e2938498005fa7e
all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in vb2_vmalloc_put
testing current HEAD 3d3abdc8ebd3c3082e4398fc73ceb4c852b66e85
testing commit 3d3abdc8ebd3c3082e4398fc73ceb4c852b66e85 with gcc (GCC) 8.4.1 20210217
kernel signature: 2f5411fa403a21f65d42c6249cb1a83806ffecfbcef9a36462aff2a96df465ab
all runs: crashed: unregister_netdevice: waiting for DEV to become free
revisions tested: 2, total time: 29m8.788605066s (build: 21m55.991335904s, test: 6m20.588613434s)
the crash still happens on HEAD
commit msg: Linux 4.14.236
crash: unregister_netdevice: waiting for DEV to become free
unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1