panic: kernel diagnostic assertion "rn != NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/net/pipex.c", line 459 Starting stack trace... panic(ffffffff833ad378) at panic+0x1d0 sys/kern/subr_prf.c:229 __assert(ffffffff833e9f94,ffffffff83400d26,1cb,ffffffff8339e9ae) at __assert+0x29 sys/kern/subr_prf.c:-1 pipex_unlink_session_locked(ffff80003c4692b0) at pipex_unlink_session_locked+0x409 pipex_destroy_all_sessions(ffff8000014a0000) at pipex_destroy_all_sessions+0xd9 pipex_rele_session sys/net/pipex.c:-1 [inline] pipex_destroy_all_sessions(ffff8000014a0000) at pipex_destroy_all_sessions+0xd9 sys/net/pipex.c:151 pppacclose(637e,81,2000,ffff80003c425a20) at pppacclose+0x16f sys/net/if_pppx.c:1335 spec_close(ffff80002ebd67e0) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd807dbbab38,81,fffffd80097fd0d0,ffff80003c425a20) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806cedf8e0,ffff80003c425a20) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806cedf8e0,ffff80003c425a20) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615 fdrop(fffffd806cedf8e0,ffff80003c425a20) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806cedf8e0,ffff80003c425a20) at closef+0x192 sys/kern/kern_descrip.c:1264 syscall(ffff80002ebd6a40) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002ebd6a40) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xbddf3ff0980, count: 245 End of stack trace.