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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id t18sm4582599pfg.111.2021.08.17.23.24.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Aug 2021 23:24:15 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Christophe Leroy , Sudeep Holla , linuxppc-dev@lists.ozlabs.org, kernel test robot , "Gustavo A. R. Silva" , Greg Kroah-Hartman , Andrew Morton , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-staging@lists.linux.dev, linux-block@vger.kernel.org, linux-kbuild@vger.kernel.org, clang-built-linux@googlegroups.com, Rasmus Villemoes , linux-hardening@vger.kernel.org Subject: [PATCH v2 57/63] powerpc/signal32: Use struct_group() to zero spe regs Date: Tue, 17 Aug 2021 23:05:27 -0700 Message-Id: <20210818060533.3569517-58-keescook@chromium.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210818060533.3569517-1-keescook@chromium.org> References: <20210818060533.3569517-1-keescook@chromium.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2908; h=from:subject; bh=uD1y/xoxNTfC/kMxy1YHPqDr4W4r5gvR6/3LUb/d/+Q=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBhHKMqjnaaYE2W2OottJ48+Kv314H+c4/L+2RqMHXv r7V1BciJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYRyjKgAKCRCJcvTf3G3AJgmYD/ 4xOx64rrId3koq1dIVBd1c7qtDRXBXq8ocvbv6TiAzQ5OW2IJsAcesmEDGB0aarLTux96zhVYvPuEY ekfg39GKhCgEPeb5jXP+UH57m9qopfeReANE1S4LvEsOJWuHGa5N2yh0MVFMYdstmPHkfTVtOzOdnW 4FpfS36c3/G650GjYZjHYGK93aUv37ocoMf05CH9DSjWcOrGk+21jowTwXALShjZMmIjz5FWSiAPe+ +1eUzjLiqUeJOGZ7Lv40/p3giVTD2/7lEzVVufOf7KMLHvSJmrltr2bLt88CSW+0Qs2cDc8kDwit4g NSusBANylY1K/6uJsrHXOzr8UYkdtB6bsttgeE9V1+wOYhLMeNib3XArxbwXJKppaNHkpLdAyqOc1N hNWxNmFkEb7gLQI+lgaRv2CySpbhIO+o8h7UWzfZ9W2P7Sz8/0+TLD68DRwxBbPxMHy7FpShanbdlR HAvsXrcU8SaCn8kjeuW7pbNPk+pnaYiQiMH5cl3iCfgq1I13gvGVNmMUEdqsNskPE6H1JjH3DkRQLj i7n33M3844UZk+msL24HAJukYQmiAtXqJDGZb3S179NpLnEREMRQveIz0XRN96WDiRCpbvwy644xQe qmxn1RnVllos5p0W46DDS5Z/a2ezsgCPxronRiihYw6gD81m/cUYTrPKHDSw== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memset(), avoid intentionally writing across neighboring fields. Add a struct_group() for the spe registers so that memset() can correctly reason about the size: In function 'fortify_memset_chk', inlined from 'restore_user_regs.part.0' at arch/powerpc/kernel/signal_32.c:539:3: >> include/linux/fortify-string.h:195:4: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] 195 | __write_overflow_field(); | ^~~~~~~~~~~~~~~~~~~~~~~~ Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Christophe Leroy Cc: Sudeep Holla Cc: linuxppc-dev@lists.ozlabs.org Reported-by: kernel test robot Signed-off-by: Kees Cook --- arch/powerpc/include/asm/processor.h | 6 ++++-- arch/powerpc/kernel/signal_32.c | 6 +++--- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index f348e564f7dd..05dc567cb9a8 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -191,8 +191,10 @@ struct thread_struct { int used_vsr; /* set if process has used VSX */ #endif /* CONFIG_VSX */ #ifdef CONFIG_SPE - unsigned long evr[32]; /* upper 32-bits of SPE regs */ - u64 acc; /* Accumulator */ + struct_group(spe, + unsigned long evr[32]; /* upper 32-bits of SPE regs */ + u64 acc; /* Accumulator */ + ); unsigned long spefscr; /* SPE & eFP status */ unsigned long spefscr_last; /* SPEFSCR value on last prctl call or trap return */ diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index 0608581967f0..77b86caf5c51 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -532,11 +532,11 @@ static long restore_user_regs(struct pt_regs *regs, regs_set_return_msr(regs, regs->msr & ~MSR_SPE); if (msr & MSR_SPE) { /* restore spe registers from the stack */ - unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs, - ELF_NEVRREG * sizeof(u32), failed); + unsafe_copy_from_user(¤t->thread.spe, &sr->mc_vregs, + sizeof(current->thread.spe), failed); current->thread.used_spe = true; } else if (current->thread.used_spe) - memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32)); + memset(¤t->thread.spe, 0, sizeof(current->thread.spe)); /* Always get SPEFSCR back */ unsafe_get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs + ELF_NEVRREG, failed); -- 2.30.2