Page MenuHomeFreeBSD

D27666.diff
No OneTemporary

D27666.diff

diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c
--- a/sys/kern/imgact_elf.c
+++ b/sys/kern/imgact_elf.c
@@ -161,19 +161,33 @@
"");
#define ASLR_NODE_OID __CONCAT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), _aslr)
-static int __elfN(aslr_enabled) = 0;
+/*
+ * While for 64-bit machines ASLR works properly, there are
+ * still some problems when using 32-bit architectures. For this
+ * reason ASLR is only enabled by default when running native
+ * 64-bit non-PIE executables.
+ */
+static int __elfN(aslr_enabled) = __ELF_WORD_SIZE == 64;
SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, enable, CTLFLAG_RWTUN,
&__elfN(aslr_enabled), 0,
__XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE))
": enable address map randomization");
-static int __elfN(pie_aslr_enabled) = 0;
+/*
+ * Enable ASLR only for 64-bit PIE binaries by default.
+ */
+static int __elfN(pie_aslr_enabled) = __ELF_WORD_SIZE == 64;
SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, pie_enable, CTLFLAG_RWTUN,
&__elfN(pie_aslr_enabled), 0,
__XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE))
": enable address map randomization for PIE binaries");
-static int __elfN(aslr_honor_sbrk) = 1;
+/*
+ * Sbrk is now deprecated and it can be assumed, that in most
+ * cases it will not be used anyway. This setting is valid only
+ * for the ASLR enabled and allows for utilizing the bss grow region.
+ */
+static int __elfN(aslr_honor_sbrk) = 0;
SYSCTL_INT(ASLR_NODE_OID, OID_AUTO, honor_sbrk, CTLFLAG_RW,
&__elfN(aslr_honor_sbrk), 0,
__XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": assume sbrk is used");

File Metadata

Mime Type
text/plain
Expires
Sat, Nov 9, 8:53 PM (18 h, 43 m)
Storage Engine
blob
Storage Format
Raw Data
Storage Handle
14565614
Default Alt Text
D27666.diff (1 KB)

Event Timeline