From 66a5c40f60f5d88ad8d47ba6a4ba05892853fa1f Mon Sep 17 00:00:00 2001 From: Tanzir Hasan Date: Tue, 26 Dec 2023 18:00:00 +0000 Subject: kernel.h: removed REPEAT_BYTE from kernel.h This patch creates wordpart.h and includes it in asm/word-at-a-time.h for all architectures. WORD_AT_A_TIME_CONSTANTS depends on kernel.h because of REPEAT_BYTE. Moving this to another header and including it where necessary allows us to not include the bloated kernel.h. Making this implicit dependency on REPEAT_BYTE explicit allows for later improvements in the lib/string.c inclusion list. Suggested-by: Al Viro Suggested-by: Andy Shevchenko Signed-off-by: Tanzir Hasan Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20231226-libstringheader-v6-1-80aa08c7652c@google.com Signed-off-by: Kees Cook --- arch/x86/include/asm/word-at-a-time.h | 3 ++- arch/x86/kvm/mmu/mmu.c | 1 + 2 files changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/x86') diff --git a/arch/x86/include/asm/word-at-a-time.h b/arch/x86/include/asm/word-at-a-time.h index 46b4f1f7f354..e8d7d4941c4c 100644 --- a/arch/x86/include/asm/word-at-a-time.h +++ b/arch/x86/include/asm/word-at-a-time.h @@ -2,7 +2,8 @@ #ifndef _ASM_WORD_AT_A_TIME_H #define _ASM_WORD_AT_A_TIME_H -#include +#include +#include /* * This is largely generic for little-endian machines, but the diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 2d6cdeab1f8a..6bb42b4fddb4 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -47,6 +47,7 @@ #include #include #include +#include #include #include -- cgit From 918327e9b7ffb45321cbb4b9b86b58ec555fe6b3 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Sun, 28 Jan 2024 10:45:29 -0800 Subject: ubsan: Remove CONFIG_UBSAN_SANITIZE_ALL For simplicity in splitting out UBSan options into separate rules, remove CONFIG_UBSAN_SANITIZE_ALL, effectively defaulting to "y", which is how it is generally used anyway. (There are no ":= y" cases beyond where a specific file is enabled when a top-level ":= n" is in effect.) Cc: Andrey Konovalov Cc: Marco Elver Cc: linux-doc@vger.kernel.org Cc: linux-kbuild@vger.kernel.org Signed-off-by: Kees Cook --- arch/x86/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5edec175b9bf..1c4c326a3640 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -100,7 +100,7 @@ config X86 select ARCH_HAS_STRICT_MODULE_RWX select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE select ARCH_HAS_SYSCALL_WRAPPER - select ARCH_HAS_UBSAN_SANITIZE_ALL + select ARCH_HAS_UBSAN select ARCH_HAS_DEBUG_WX select ARCH_HAS_ZONE_DMA_SET if EXPERT select ARCH_HAVE_NMI_SAFE_CMPXCHG -- cgit From 475ddf1fce1ec4826c8dda40ec59f7f83a7aadb8 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 7 Apr 2023 12:27:13 -0700 Subject: fortify: Split reporting and avoid passing string pointer In preparation for KUnit testing and further improvements in fortify failure reporting, split out the report and encode the function and access failure (read or write overflow) into a single u8 argument. This mainly ends up saving a tiny bit of space in the data segment. For a defconfig with FORTIFY_SOURCE enabled: $ size gcc/vmlinux.before gcc/vmlinux.after text data bss dec hex filename 26132309 9760658 2195460 38088427 2452eeb gcc/vmlinux.before 26132386 9748382 2195460 38076228 244ff44 gcc/vmlinux.after Reviewed-by: Alexander Lobakin Signed-off-by: Kees Cook --- arch/x86/boot/compressed/misc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86') diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index b99e08e6815b..c9971b9dbb09 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -496,7 +496,7 @@ asmlinkage __visible void *extract_kernel(void *rmode, unsigned char *output) return output + entry_offset; } -void fortify_panic(const char *name) +void __fortify_panic(const u8 reason) { error("detected buffer overflow"); } -- cgit From 3d965b33e40d973b450cb0212913f039476c16f4 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 7 Apr 2023 12:27:16 -0700 Subject: fortify: Improve buffer overflow reporting Improve the reporting of buffer overflows under CONFIG_FORTIFY_SOURCE to help accelerate debugging efforts. The calculations are all just sitting in registers anyway, so pass them along to the function to be reported. For example, before: detected buffer overflow in memcpy and after: memcpy: detected buffer overflow: 4096 byte read of buffer size 1 Link: https://lore.kernel.org/r/20230407192717.636137-10-keescook@chromium.org Signed-off-by: Kees Cook --- arch/x86/boot/compressed/misc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86') diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index c9971b9dbb09..1844da203da9 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -496,7 +496,7 @@ asmlinkage __visible void *extract_kernel(void *rmode, unsigned char *output) return output + entry_offset; } -void __fortify_panic(const u8 reason) +void __fortify_panic(const u8 reason, size_t avail, size_t size) { error("detected buffer overflow"); } -- cgit From aaa8736370db1a78f0e8434344a484f9fd20be3b Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 27 Feb 2024 09:51:12 -0800 Subject: x86, relocs: Ignore relocations in .notes section When building with CONFIG_XEN_PV=y, .text symbols are emitted into the .notes section so that Xen can find the "startup_xen" entry point. This information is used prior to booting the kernel, so relocations are not useful. In fact, performing relocations against the .notes section means that the KASLR base is exposed since /sys/kernel/notes is world-readable. To avoid leaking the KASLR base without breaking unprivileged tools that are expecting to read /sys/kernel/notes, skip performing relocations in the .notes section. The values readable in .notes are then identical to those found in System.map. Reported-by: Guixiong Wei Closes: https://lore.kernel.org/all/20240218073501.54555-1-guixiongwei@gmail.com/ Fixes: 5ead97c84fa7 ("xen: Core Xen implementation") Fixes: da1a679cde9b ("Add /sys/kernel/notes") Reviewed-by: Juergen Gross Signed-off-by: Kees Cook --- arch/x86/tools/relocs.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/x86') diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c index a3bae2b24626..b029fb81ebee 100644 --- a/arch/x86/tools/relocs.c +++ b/arch/x86/tools/relocs.c @@ -653,6 +653,14 @@ static void print_absolute_relocs(void) if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) { continue; } + /* + * Do not perform relocations in .notes section; any + * values there are meant for pre-boot consumption (e.g. + * startup_xen). + */ + if (sec_applies->shdr.sh_type == SHT_NOTE) { + continue; + } sh_symtab = sec_symtab->symtab; sym_strtab = sec_symtab->link->strtab; for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) { -- cgit