panic: kernel diagnostic assertion "rn != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/net/pipex.c", line 459 Starting stack trace... panic(ffffffff833aa1bb) at panic+0x1d0 sys/kern/subr_prf.c:229 __assert(ffffffff833ec59c,ffffffff8340899b,1cb,ffffffff833a6241) at __assert+0x29 sys/kern/subr_prf.c:-1 pipex_unlink_session_locked(ffff8000333ea098) at pipex_unlink_session_locked+0x409 pipex_destroy_all_sessions(ffff800001523000) at pipex_destroy_all_sessions+0xd9 pipex_rele_session sys/net/pipex.c:-1 [inline] pipex_destroy_all_sessions(ffff800001523000) at pipex_destroy_all_sessions+0xd9 sys/net/pipex.c:151 pppacclose(637e,41,2000,ffff80003c4da2d0) at pppacclose+0x16f sys/net/if_pppx.c:1335 spec_close(ffff80003c4d8ef0) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8060b7a998,41,fffffd80097fd2d8,ffff80003c4da2d0) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806008dcd0,ffff80003c4da2d0) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806008dcd0,ffff80003c4da2d0) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806008dcd0,ffff80003c4da2d0) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806008dcd0,ffff80003c4da2d0) at closef+0x192 sys/kern/kern_descrip.c:1264 fdfree(ffff80003c4da2d0) at fdfree+0x116 sys/kern/kern_descrip.c:1195 exit1(ffff80003c4da2d0,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215 sys_exit(ffff80003c4da2d0,ffff80003c4d9260,ffff80003c4d91b0) at sys_exit+0x1a sys/kern/kern_exit.c:-1 syscall(ffff80003c4d9260) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c4d9260) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:765 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x74342c8bdd90, count: 242 End of stack trace.