diff options
| author | Jamie Gritton <jamie@FreeBSD.org> | 2026-06-09 22:31:40 +0000 |
|---|---|---|
| committer | Mark Johnston <markj@FreeBSD.org> | 2026-06-30 02:32:57 +0000 |
| commit | 029528221261c56a5c6480e897c861fc91583315 (patch) | |
| tree | 5168efa0addbb1fb4cf1dead73ca3ec135628e9d | |
| parent | 2baf56862bfd8fe498df54984435bc3975f83298 (diff) | |
jail: Don't double-free the current prison in kern_jail_set/get
Approved by: so
Security: FreeBSD-SA-26:38.jail
Security: CVE-2026-49419
Reported by: Yuxiang Yang, et al <yangyx22 at mails.tsinghua.edu.cn>
Discussed with: markj
(cherry picked from commit b52dc2067618fc73e8d4d20e4035d1a67a8b455d)
(cherry picked from commit 4938fd9361b497241df8f442f1f87cc73ef81d6c)
| -rw-r--r-- | sys/kern/kern_jail.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c index 523b7e314a10..40b2d7a69e3e 100644 --- a/sys/kern/kern_jail.c +++ b/sys/kern/kern_jail.c @@ -1097,14 +1097,17 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags) * Look up and create jails based on the * descriptor's prison. */ - prison_free(mypr); - error = jaildesc_find(td, jfd_in, &mypr, NULL); + struct prison *jdpr; + + error = jaildesc_find(td, jfd_in, &jdpr, NULL); if (error != 0) { vfs_opterror(opts, error == ENOENT ? "descriptor to dead jail" : "not a jail descriptor"); goto done_errmsg; } + prison_free(mypr); + mypr = jdpr; if ((flags & JAIL_CREATE) && mypr->pr_childmax == 0) { error = EPERM; goto done_free; @@ -2545,14 +2548,17 @@ kern_jail_get(struct thread *td, struct uio *optuio, int flags) } if (flags & JAIL_AT_DESC) { /* Look up jails based on the descriptor's prison. */ - prison_free(mypr); - error = jaildesc_find(td, jfd_in, &mypr, NULL); + struct prison *jdpr; + + error = jaildesc_find(td, jfd_in, &jdpr, NULL); if (error != 0) { vfs_opterror(opts, error == ENOENT ? "descriptor to dead jail" : "not a jail descriptor"); goto done; } + prison_free(mypr); + mypr = jdpr; } if (flags & (JAIL_GET_DESC | JAIL_OWN_DESC)) { /* Allocate a jail descriptor to return later. */ |