doc/share/security/patches/SA-00:41/elf.patch
Bjoern A. Zeeb 3571e53040 Import FreeBSD Security Advisories and Errata Notices, as well as their
patches for easier mirroring, to eliminate a special copy, to make
www.freebsd.org/security a full copy of security.freebsd.org and be
eventually be the same.

For now files are just sitting there.   The symlinks are missing.

Discussed on:	www (repository location)
Discussed with:	simon (so)
2012-08-15 06:19:40 +00:00

65 lines
1.8 KiB
Diff

--- imgact_elf.c 2000/04/30 18:51:39 1.75
+++ imgact_elf.c 2000/07/23 22:19:49 1.78
@@ -190,6 +190,21 @@
object = vp->v_object;
error = 0;
+ /*
+ * It's necessary to fail if the filsz + offset taken from the
+ * header is greater than the actual file pager object's size.
+ * If we were to allow this, then the vm_map_find() below would
+ * walk right off the end of the file object and into the ether.
+ *
+ * While I'm here, might as well check for something else that
+ * is invalid: filsz cannot be greater than memsz.
+ */
+ if ((off_t)filsz + offset > object->un_pager.vnp.vnp_size ||
+ filsz > memsz) {
+ uprintf("elf_load_section: truncated ELF file\n");
+ return (ENOEXEC);
+ }
+
map_addr = trunc_page((vm_offset_t)vmaddr);
file_addr = trunc_page(offset);
@@ -341,6 +356,12 @@
}
error = exec_map_first_page(imgp);
+ /*
+ * Also make certain that the interpreter stays the same, so set
+ * its VTEXT flag, too.
+ */
+ if (error == 0)
+ nd.ni_vp->v_flag |= VTEXT;
VOP_UNLOCK(nd.ni_vp, 0, p);
if (error)
goto fail;
@@ -449,6 +470,17 @@
/*
* From this point on, we may have resources that need to be freed.
*/
+
+ /*
+ * Yeah, I'm paranoid. There is every reason in the world to get
+ * VTEXT now since from here on out, there are places we can have
+ * a context switch. Better safe than sorry; I really don't want
+ * the file to change while it's being loaded.
+ */
+ simple_lock(&imgp->vp->v_interlock);
+ imgp->vp->v_flag |= VTEXT;
+ simple_unlock(&imgp->vp->v_interlock);
+
if ((error = exec_extract_strings(imgp)) != 0)
goto fail;
@@ -610,9 +642,6 @@
imgp->auxargs = elf_auxargs;
imgp->interpreted = 0;
- /* don't allow modifying the file while we run it */
- imgp->vp->v_flag |= VTEXT;
-
fail:
return error;
}