Re: Bug: Write fault blocked by KUAP! (kernel 6.2-rc6, Talos II)
From: Erhard F. <hidden>
Date: 2023-02-16 15:21:39
On Thu, 9 Feb 2023 07:21:55 +0000 Christophe Leroy [off-list ref] wrote:
quoted hunk ↗ jump to hunk
An easy fix would probably be to also check the suffix as a prefixed instruction with 0 as suffix is not valid :diff --git a/arch/powerpc/include/asm/inst.hb/arch/powerpc/include/asm/inst.h index 684d3f453282..87084a52598b 100644--- a/arch/powerpc/include/asm/inst.h +++ b/arch/powerpc/include/asm/inst.h@@ -86,7 +86,7 @@ static inline ppc_inst_t ppc_inst_read(const u32 *ptr) static inline bool ppc_inst_prefixed(ppc_inst_t x) { - return IS_ENABLED(CONFIG_PPC64) && ppc_inst_primary_opcode(x) ==OP_PREFIX; + return IS_ENABLED(CONFIG_PPC64) && ppc_inst_primary_opcode(x) == OP_PREFIX && ppc_inst_suffix(x); } static inline ppc_inst_t ppc_inst_swab(ppc_inst_t x)
Your patch works fine for me! Applied on top of v6.2-rc7 and in the resulting kernel the Write fault is gone. Thanks! Regards, Erhard