[PATCH 4.9 88/90] ARM: 8958/1: rename missed uaccess .fixup section

From: Greg Kroah-Hartman
Date: Thu Mar 19 2020 - 09:13:42 EST


From: Kees Cook <keescook@xxxxxxxxxxxx>

commit f87b1c49bc675da30d8e1e8f4b60b800312c7b90 upstream.

When the uaccess .fixup section was renamed to .text.fixup, one case was
missed. Under ld.bfd, the orphaned section was moved close to .text
(since they share the "ax" bits), so things would work normally on
uaccess faults. Under ld.lld, the orphaned section was placed outside
the .text section, making it unreachable.

Link: https://github.com/ClangBuiltLinux/linux/issues/282
Link: https://bugs.chromium.org/p/chromium/issues/detail?id=1020633#c44
Link: https://lore.kernel.org/r/nycvar.YSQ.7.76.1912032147340.17114@xxxxxxxxxxx
Link: https://lore.kernel.org/lkml/202002071754.F5F073F1D@keescook/

Fixes: c4a84ae39b4a5 ("ARM: 8322/1: keep .text and .fixup regions closer together")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/arm/lib/copy_from_user.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm/lib/copy_from_user.S
+++ b/arch/arm/lib/copy_from_user.S
@@ -100,7 +100,7 @@ ENTRY(arm_copy_from_user)

ENDPROC(arm_copy_from_user)

- .pushsection .fixup,"ax"
+ .pushsection .text.fixup,"ax"
.align 0
copy_abort_preamble
ldmfd sp!, {r1, r2, r3}