From aly at crater.dragonflybsd.org  Sun Nov  1 04:00:30 2026
From: aly at crater.dragonflybsd.org (Aaron LI)
Date: Sun, 01 Nov 2026 04:00:30 -0800 (PST)
Subject: git: kernel - Fix page fault in the jail unmount check
Message-ID: <20261101120031.C78AE33E473F@crater.dragonflybsd.org>


commit 6248a150a706d1088447e1326b7d5b11b4a3a508
Author: David Bidner <david at crap.solutions>
Date:   Sun Sep 27 19:51:41 2026 +0200

    kernel - Fix page fault in the jail unmount check
    
    sys_unmount() printed the "does not belong to this jail" message using
    uap->path, a user-space pointer.  With SMAP enabled, kprintf() -> strlen()
    faults on it.
    
    Use nd.nl_path, the kernel copy that nlookup_init() already made.
    
    Panic reproduce steps, assuming a jail is prepared at `/jail`:
    ```
    jail# umount /dev
    ```
    
    Reported-by: tuxillo
    Bug: https://bugs.dragonflybsd.org/issues/3386

Summary of changes:
 sys/kern/vfs_syscalls.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/6248a150a706d1088447e1326b7d5b11b4a3a508


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