To reproduce, just start a buildkernel/buildworld with WITH_META_MODE and KASAN enabled. According to markj@, this might be a false-positive due to LLVM. FreeBSD clang version 17.0.6 (https://github.com/llvm/llvm-project.git llvmorg-17.0.6-0-g6009708b4367) panic: ASan: Invalid access, 8-byte write at 0xfffffe00457d2760, UseAfterScope(f8) cpuid = 0 time = 1712697087 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0xa5/frame 0xfffffe00457d2290 kdb_backtrace() at kdb_backtrace+0xc6/frame 0xfffffe00457d23f0 vpanic() at vpanic+0x210/frame 0xfffffe00457d2590 panic() at panic+0xb5/frame 0xfffffe00457d2650 kasan_code_name() at kasan_code_name/frame 0xfffffe00457d2720 devfs_get_cdevpriv() at devfs_get_cdevpriv+0x52/frame 0xfffffe00457d2740 filemon_ioctl() at filemon_ioctl+0x23/frame 0xfffffe00457d2790 devfs_ioctl() at devfs_ioctl+0x1f6/frame 0xfffffe00457d2870 vn_ioctl() at vn_ioctl+0x235/frame 0xfffffe00457d2a80 devfs_ioctl_f() at devfs_ioctl_f+0x6c/frame 0xfffffe00457d2ad0 kern_ioctl() at kern_ioctl+0x3a1/frame 0xfffffe00457d2bb0 sys_ioctl() at sys_ioctl+0x247/frame 0xfffffe00457d2d10 amd64_syscall() at amd64_syscall+0x365/frame 0xfffffe00457d2f30 fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe00457d2f30 --- syscall (54, FreeBSD ELF64, ioctl), rip = 0xb5e318e48fa, rsp = 0xb5e2f280d78, rbp = 0xb5e2f280da0 --- KDB: enter: panic [ thread pid 3131 tid 100193 ] Stopped at kdb_enter+0x34: movq $0,0x1ef4261(%rip) db>
Hi christos@, please check if https://reviews.freebsd.org/rG68a3a7fc94833020403190c20bd9be186c6156ce solves the problem. Ka Ho
Thank you.