linux-kernel - [PATCH -mm 1/2] ELF: make BAD

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [day] [month] [year] [list]

Date:   Sun, 15 Dec 2019 15:43:55 +0300
From:   Alexey Dobriyan <adobriyan@...il.com>
To:     akpm@...ux-foundation.org
Cc:     linux-kernel@...r.kernel.org
Subject: [PATCH -mm 1/2] ELF: make BAD_ADDR() unlikely

If some mapping goes past TASK_SIZE it will be rejected by kernel
which means no such userspace binaries exist.

Mark every such check as unlikely.

Signed-off-by: Alexey Dobriyan <adobriyan@...il.com>
---

 fs/binfmt_elf.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -97,7 +97,7 @@ static struct linux_binfmt elf_format = {
 	.min_coredump	= ELF_EXEC_PAGESIZE,
 };
 
-#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
+#define BAD_ADDR(x) (unlikely((unsigned long)(x) >= TASK_SIZE))
 
 static int set_brk(unsigned long start, unsigned long end, int prot)
 {