panic: kernel diagnostic assertion "rn != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/net/pipex.c", line 459 Starting stack trace... panic(ffffffff833b3e24) at panic+0x1d0 sys/kern/subr_prf.c:229 __assert(ffffffff833f14b8,ffffffff834103ec,1cb,ffffffff833ad0aa) at __assert+0x29 sys/kern/subr_prf.c:-1 pipex_unlink_session_locked(ffff800034bc52a8) at pipex_unlink_session_locked+0x429 pipex_destroy_all_sessions(ffff800001638000) at pipex_destroy_all_sessions+0xd9 pipex_rele_session sys/net/pipex.c:-1 [inline] pipex_destroy_all_sessions(ffff800001638000) at pipex_destroy_all_sessions+0xd9 sys/net/pipex.c:151 pppacclose(637e,81,2000,ffff8000fffe74f8) at pppacclose+0x16f sys/net/if_pppx.c:1335 spec_close(ffff8000353da410) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8061e277f8,81,fffffd80097fd6e8,ffff8000fffe74f8) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd8065548548,ffff8000fffe74f8) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd8065548548,ffff8000fffe74f8) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd8065548548,ffff8000fffe74f8) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd8065548548,ffff8000fffe74f8) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff8000fffe74f8) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff8000fffe74f8,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff8000fffe74f8,ffff8000353da780,ffff8000353da6d0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff8000353da780) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff8000353da780) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x79cb347061d0, count: 242 End of stack trace.