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author | kib <kib@FreeBSD.org> | 2013-10-15 06:38:40 +0000 |
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committer | kib <kib@FreeBSD.org> | 2013-10-15 06:38:40 +0000 |
commit | 45444cbe669e3698df00081b4626ee47464a41ed (patch) | |
tree | e427ea3fe82951631499e3f1397e843dc06ee7de | |
parent | 5e67d6314a34b6876dd0678e12cf7c5fde1f58db (diff) | |
download | FreeBSD-src-45444cbe669e3698df00081b4626ee47464a41ed.zip FreeBSD-src-45444cbe669e3698df00081b4626ee47464a41ed.tar.gz |
Add a sysctl kern.disallow_high_osrel which disables executing the
images compiled on the world with higher major version number than the
high version number of the booted kernel. Default to disable.
Sponsored by: The FreeBSD Foundation
Discussed with: bapt
MFC after: 1 week
-rw-r--r-- | sys/kern/kern_exec.c | 14 | ||||
-rw-r--r-- | sys/sys/param.h | 2 |
2 files changed, 16 insertions, 0 deletions
diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c index 45f732b..c71c666 100644 --- a/sys/kern/kern_exec.c +++ b/sys/kern/kern_exec.c @@ -123,6 +123,11 @@ u_long ps_arg_cache_limit = PAGE_SIZE / 16; SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW, &ps_arg_cache_limit, 0, ""); +static int disallow_high_osrel; +SYSCTL_INT(_kern, OID_AUTO, disallow_high_osrel, CTLFLAG_RW, + &disallow_high_osrel, 0, + "Disallow execution of binaries built for higher version of the world"); + static int map_at_zero = 0; TUNABLE_INT("security.bsd.map_at_zero", &map_at_zero); SYSCTL_INT(_security_bsd, OID_AUTO, map_at_zero, CTLFLAG_RW, &map_at_zero, 0, @@ -552,6 +557,15 @@ interpret: vn_fullpath(td, imgp->vp, &imgp->execpath, &imgp->freepath) != 0)) imgp->execpath = args->fname; + if (disallow_high_osrel && + P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) { + error = ENOEXEC; + uprintf("Osrel %d for image %s too high\n", p->p_osrel, + imgp->execpath != NULL ? imgp->execpath : "<unresolved>"); + vn_lock(imgp->vp, LK_SHARED | LK_RETRY); + goto exec_fail_dealloc; + } + /* * Copy out strings (args and env) and initialize stack base */ diff --git a/sys/sys/param.h b/sys/sys/param.h index 981680f..9b25965 100644 --- a/sys/sys/param.h +++ b/sys/sys/param.h @@ -80,6 +80,8 @@ #define P_OSREL_SIGWAIT 700000 #define P_OSREL_SIGSEGV 700004 #define P_OSREL_MAP_ANON 800104 + +#define P_OSREL_MAJOR(x) ((x) / 100000) #endif #ifndef LOCORE |