[3.13] gh-128605: Add branch protections for x86_64 in asm_trampoline.S (GH-128606) (GH-135077) (#135083)

[3.14] gh-128605: Add branch protections for x86_64 in asm_trampoline.S (GH-128606) (GH-135077)

Apply Intel Control-flow Technology for x86-64 on asm_trampoline.S.

Required for mitigation against return-oriented programming (ROP)
and Call or Jump Oriented Programming (COP/JOP) attacks.

Manual application is required for the assembly files.

See also: https://sourceware.org/annobin/annobin.html/Test-cf-protection.html
(cherry picked from commit 899cca6dbf)

Co-authored-by: stratakis <cstratak@redhat.com>
This commit is contained in:
Miss Islington (bot) 2025-06-03 15:54:53 +02:00 committed by GitHub
parent b0c9c192f1
commit 9f3d99967c
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
2 changed files with 27 additions and 0 deletions

View file

@ -9,6 +9,9 @@
# } # }
_Py_trampoline_func_start: _Py_trampoline_func_start:
#ifdef __x86_64__ #ifdef __x86_64__
#if defined(__CET__) && (__CET__ & 1)
endbr64
#endif
sub $8, %rsp sub $8, %rsp
call *%rcx call *%rcx
add $8, %rsp add $8, %rsp
@ -34,3 +37,22 @@ _Py_trampoline_func_start:
.globl _Py_trampoline_func_end .globl _Py_trampoline_func_end
_Py_trampoline_func_end: _Py_trampoline_func_end:
.section .note.GNU-stack,"",@progbits .section .note.GNU-stack,"",@progbits
# Note for indicating the assembly code supports CET
#if defined(__x86_64__) && defined(__CET__) && (__CET__ & 1)
.section .note.gnu.property,"a"
.align 8
.long 1f - 0f
.long 4f - 1f
.long 5
0:
.string "GNU"
1:
.align 8
.long 0xc0000002
.long 3f - 2f
2:
.long 0x3
3:
.align 8
4:
#endif // __x86_64__

View file

@ -472,6 +472,11 @@ elf_init_ehframe(ELFObjectContext* ctx)
DWRF_U8(0); /* Augmentation data. */ DWRF_U8(0); /* Augmentation data. */
/* Registers saved in CFRAME. */ /* Registers saved in CFRAME. */
#ifdef __x86_64__ #ifdef __x86_64__
# if defined(__CET__) && (__CET__ & 1)
DWRF_U8(DWRF_CFA_advance_loc | 8);
# else
DWRF_U8(DWRF_CFA_advance_loc | 4);
# endif
DWRF_U8(DWRF_CFA_advance_loc | 4); DWRF_U8(DWRF_CFA_advance_loc | 4);
DWRF_U8(DWRF_CFA_def_cfa_offset); DWRF_UV(16); DWRF_U8(DWRF_CFA_def_cfa_offset); DWRF_UV(16);
DWRF_U8(DWRF_CFA_advance_loc | 6); DWRF_U8(DWRF_CFA_advance_loc | 6);