panic: kernel diagnostic assertion "rn != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/net/pipex.c", line 459
Stopped at      db_enter+0x25:  addq    $0x8,%rsp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834cb97b) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff83507068,ffffffff83522017,1cb,ffffffff834c0c20) at __assert+0x29 sys/kern/subr_prf.c:-1
pipex_unlink_session_locked(ffff80003c3e9750) at pipex_unlink_session_locked+0x429
pipex_destroy_all_sessions(ffff80000159e000) at pipex_destroy_all_sessions+0xd9 pipex_rele_session sys/net/pipex.c:-1 [inline]
pipex_destroy_all_sessions(ffff80000159e000) at pipex_destroy_all_sessions+0xd9 sys/net/pipex.c:151
pppacclose(637d,1,2000,ffff80002a222fa0) at pppacclose+0x16f sys/net/if_pppx.c:1335
spec_close(ffff80002a279e90) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(ffffee005ee40cf0,1,ffffee00097fd2d8,ffff80002a222fa0) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156
vn_closefile(ffffee006cbc3220,ffff80002a222fa0) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:298 [inline]
vn_closefile(ffffee006cbc3220,ffff80002a222fa0) at vn_closefile+0x12b sys/kern/vfs_vnops.c:621
fdrop(ffffee006cbc3220,ffff80002a222fa0) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(ffffee006cbc3220,ffff80002a222fa0) at closef+0x192 sys/kern/kern_descrip.c:1265
fdfree(ffff80002a222fa0) at fdfree+0x116 sys/kern/kern_descrip.c:1196
exit1(ffff80002a222fa0,0,0,1) at exit1+0x595 sys/kern/kern_exit.c:215
sys_exit(ffff80002a222fa0,ffff80002a27a200,ffff80002a27a150) at sys_exit+0x1a sys/kern/kern_exit.c:-1
end trace frame: 0xffff80002a27a1f0, count: 0
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