| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.10 017/123] x86: Reject x32 executables if x32 ABI not supported | Date | Wed, 12 Nov 2014 10:16:23 +0900 |
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3.10-stable review patch. If anyone has any objections, please let me know.
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From: Ben Hutchings <ben@decadent.org.uk>
commit 0e6d3112a4e95d55cf6dca88f298d5f4b8f29bd1 upstream.
It is currently possible to execve() an x32 executable on an x86_64 kernel that has only ia32 compat enabled. However all its syscalls will fail, even _exit(). This usually causes it to segfault.
Change the ELF compat architecture check so that x32 executables are rejected if we don't support the x32 ABI.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Link: http://lkml.kernel.org/r/1410120305.6822.9.camel@decadent.org.uk Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/x86/include/asm/elf.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -155,8 +155,9 @@ do { \ #define elf_check_arch(x) \ ((x)->e_machine == EM_X86_64) -#define compat_elf_check_arch(x) \ - (elf_check_arch_ia32(x) || (x)->e_machine == EM_X86_64) +#define compat_elf_check_arch(x) \ + (elf_check_arch_ia32(x) || \ + (IS_ENABLED(CONFIG_X86_X32_ABI) && (x)->e_machine == EM_X86_64)) #if __USER32_DS != __USER_DS # error "The following code assumes __USER32_DS == __USER_DS"
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