stable/10 panic

[hiren panchasara]

This is the new one I've seen happening intermittently on the same set of hosts:

panic: Unlocked pipe passed to pipeunlock
cpuid = 8
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe048e18a7e0
kdb_backtrace() at kdb_backtrace+0x39/frame 0xfffffe048e18a890
vpanic() at vpanic+0x126/frame 0xfffffe048e18a8d0
kassert_panic() at kassert_panic+0x136/frame 0xfffffe048e18a940
pipe_write() at pipe_write+0xa00/frame 0xfffffe048e18a9f0
dofilewrite() at dofilewrite+0x85/frame 0xfffffe048e18aa40
kern_writev() at kern_writev+0x65/frame 0xfffffe048e18aa90
sys_write() at sys_write+0x63/frame 0xfffffe048e18aae0
ia32_syscall() at ia32_syscall+0x255/frame 0xfffffe048e18abf0
Xint0x80_syscall() at Xint0x80_syscall+0x95/frame 0xfffffe048e18abf0