From: "Naveen N. Rao" naveen.n.rao@linux.vnet.ibm.com

commit 65d9a9a60fd71be964effb2e94747a6acb6e7015 upstream.

As requested (http://lkml.kernel.org/r/87ee0q7b92.fsf@email.froward.int.ebiederm.org), this series converts weak functions in kexec to use the #ifdef approach.

Quoting the 3e35142ef99fe ("kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add]") changelog:

: Since commit d1bcae833b32f1 ("ELF: Don't generate unused section symbols") : [1], binutils (v2.36+) started dropping section symbols that it thought : were unused. This isn't an issue in general, but with kexec_file.c, gcc : is placing kexec_arch_apply_relocations[_add] into a separate : .text.unlikely section and the section symbol ".text.unlikely" is being : dropped. Due to this, recordmcount is unable to find a non-weak symbol in : .text.unlikely to generate a relocation record against.

This patch (of 2);

Drop __weak attribute from functions in kexec_file.c: - arch_kexec_kernel_image_probe() - arch_kimage_file_post_load_cleanup() - arch_kexec_kernel_image_load() - arch_kexec_locate_mem_hole() - arch_kexec_kernel_verify_sig()

arch_kexec_kernel_image_load() calls into kexec_image_load_default(), so drop the static attribute for the latter.

arch_kexec_kernel_verify_sig() is not overridden by any architecture, so drop the __weak attribute.

Link: https://lkml.kernel.org/r/cover.1656659357.git.naveen.n.rao@linux.vnet.ibm.c... Link: https://lkml.kernel.org/r/2cd7ca1fe4d6bb6ca38e3283c717878388ed6788.165665935... Signed-off-by: Naveen N. Rao naveen.n.rao@linux.vnet.ibm.com Suggested-by: Eric Biederman ebiederm@xmission.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Mimi Zohar zohar@linux.ibm.com Signed-off-by: Michal Suchanek msuchanek@suse.de --- arch/arm64/include/asm/kexec.h | 4 ++- arch/powerpc/include/asm/kexec.h | 9 +++++++ arch/s390/include/asm/kexec.h | 3 +++ arch/x86/include/asm/kexec.h | 6 +++++ include/linux/kexec.h | 44 +++++++++++++++++++++++++++----- kernel/kexec_file.c | 35 ++----------------------- 6 files changed, 61 insertions(+), 40 deletions(-)

diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h index 00dbcc71aeb2..91d81824f869 100644 --- a/arch/arm64/include/asm/kexec.h +++ b/arch/arm64/include/asm/kexec.h @@ -103,7 +103,9 @@ extern const struct kexec_file_ops kexec_image_ops;

struct kimage;

-extern int arch_kimage_file_post_load_cleanup(struct kimage *image); +int arch_kimage_file_post_load_cleanup(struct kimage *image); +#define arch_kimage_file_post_load_cleanup arch_kimage_file_post_load_cleanup + extern int load_other_segments(struct kimage *image, unsigned long kernel_load_addr, unsigned long kernel_size, char *initrd, unsigned long initrd_len, diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h index 88d0d7cf3a79..6152fa220054 100644 --- a/arch/powerpc/include/asm/kexec.h +++ b/arch/powerpc/include/asm/kexec.h @@ -119,6 +119,15 @@ int setup_purgatory(struct kimage *image, const void *slave_code, #ifdef CONFIG_PPC64 struct kexec_buf;

+int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, unsigned long buf_len); +#define arch_kexec_kernel_image_probe arch_kexec_kernel_image_probe + +int arch_kimage_file_post_load_cleanup(struct kimage *image); +#define arch_kimage_file_post_load_cleanup arch_kimage_file_post_load_cleanup + +int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf); +#define arch_kexec_locate_mem_hole arch_kexec_locate_mem_hole + int load_crashdump_segments_ppc64(struct kimage *image, struct kexec_buf *kbuf); int setup_purgatory_ppc64(struct kimage *image, const void *slave_code, diff --git a/arch/s390/include/asm/kexec.h b/arch/s390/include/asm/kexec.h index 63098df81c9f..d13bd221cd37 100644 --- a/arch/s390/include/asm/kexec.h +++ b/arch/s390/include/asm/kexec.h @@ -92,5 +92,8 @@ int arch_kexec_apply_relocations_add(struct purgatory_info *pi, const Elf_Shdr *relsec, const Elf_Shdr *symtab); #define arch_kexec_apply_relocations_add arch_kexec_apply_relocations_add + +int arch_kimage_file_post_load_cleanup(struct kimage *image); +#define arch_kimage_file_post_load_cleanup arch_kimage_file_post_load_cleanup #endif #endif /*_S390_KEXEC_H */ diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h index c7c924e15011..5b6e2ae54906 100644 --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -193,6 +193,12 @@ int arch_kexec_apply_relocations_add(struct purgatory_info *pi, const Elf_Shdr *relsec, const Elf_Shdr *symtab); #define arch_kexec_apply_relocations_add arch_kexec_apply_relocations_add + +void *arch_kexec_kernel_image_load(struct kimage *image); +#define arch_kexec_kernel_image_load arch_kexec_kernel_image_load + +int arch_kimage_file_post_load_cleanup(struct kimage *image); +#define arch_kimage_file_post_load_cleanup arch_kimage_file_post_load_cleanup #endif #endif

diff --git a/include/linux/kexec.h b/include/linux/kexec.h index cf042d41c87b..f1e5327a7bf8 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -182,21 +182,53 @@ int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name, void *buf, unsigned int size, bool get_value); void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name); +void *kexec_image_load_default(struct kimage *image); + +#ifndef arch_kexec_kernel_image_probe +static inline int +arch_kexec_kernel_image_probe(struct kimage *image, void *buf, unsigned long buf_len) +{ + return kexec_image_probe_default(image, buf, buf_len); +} +#endif + +#ifndef arch_kimage_file_post_load_cleanup +static inline int arch_kimage_file_post_load_cleanup(struct kimage *image) +{ + return kexec_image_post_load_cleanup_default(image); +} +#endif + +#ifndef arch_kexec_kernel_image_load +static inline void *arch_kexec_kernel_image_load(struct kimage *image) +{ + return kexec_image_load_default(image); +} +#endif

-/* Architectures may override the below functions */ -int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, - unsigned long buf_len); -void *arch_kexec_kernel_image_load(struct kimage *image); -int arch_kimage_file_post_load_cleanup(struct kimage *image); #ifdef CONFIG_KEXEC_SIG int arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, unsigned long buf_len); #endif -int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf);

extern int kexec_add_buffer(struct kexec_buf *kbuf); int kexec_locate_mem_hole(struct kexec_buf *kbuf);

+#ifndef arch_kexec_locate_mem_hole +/** + * arch_kexec_locate_mem_hole - Find free memory to place the segments. + * @kbuf: Parameters for the memory search. + * + * On success, kbuf->mem will have the start address of the memory region found. + * + * Return: 0 on success, negative errno on error. + */ +static inline int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf) +{ + return kexec_locate_mem_hole(kbuf); +} +#endif + /* Alignment required for elf header segment */ #define ELF_CORE_HEADER_ALIGN 4096

diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index f7a4fd4d243f..620021679405 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -62,14 +62,7 @@ int kexec_image_probe_default(struct kimage *image, void *buf, return ret; }

-/* Architectures can provide this probe function */ -int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf, - unsigned long buf_len) -{ - return kexec_image_probe_default(image, buf, buf_len); -} - -static void *kexec_image_load_default(struct kimage *image) +void *kexec_image_load_default(struct kimage *image) { if (!image->fops || !image->fops->load) return ERR_PTR(-ENOEXEC); @@ -80,11 +73,6 @@ static void *kexec_image_load_default(struct kimage *image) image->cmdline_buf_len); }

-void * __weak arch_kexec_kernel_image_load(struct kimage *image) -{ - return kexec_image_load_default(image); -} - int kexec_image_post_load_cleanup_default(struct kimage *image) { if (!image->fops || !image->fops->cleanup) @@ -93,11 +81,6 @@ int kexec_image_post_load_cleanup_default(struct kimage *image) return image->fops->cleanup(image->image_loader_data); }

-int __weak arch_kimage_file_post_load_cleanup(struct kimage *image) -{ - return kexec_image_post_load_cleanup_default(image); -} - #ifdef CONFIG_KEXEC_SIG static int kexec_image_verify_sig_default(struct kimage *image, void *buf, unsigned long buf_len) @@ -110,8 +93,7 @@ static int kexec_image_verify_sig_default(struct kimage *image, void *buf, return image->fops->verify_sig(buf, buf_len); }

-int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, - unsigned long buf_len) +int arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, unsigned long buf_len) { return kexec_image_verify_sig_default(image, buf, buf_len); } @@ -616,19 +598,6 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf) return ret == 1 ? 0 : -EADDRNOTAVAIL; }

-/** - * arch_kexec_locate_mem_hole - Find free memory to place the segments. - * @kbuf: Parameters for the memory search. - * - * On success, kbuf->mem will have the start address of the memory region found. - * - * Return: 0 on success, negative errno on error. - */ -int __weak arch_kexec_locate_mem_hole(struct kexec_buf *kbuf) -{ - return kexec_locate_mem_hole(kbuf); -} - /** * kexec_add_buffer - place a buffer in a kexec segment * @kbuf: Buffer contents and memory parameters.

From: Coiby Xu coxu@redhat.com

commit 689a71493bd2f31c024f8c0395f85a1fd4b2138e upstream.

Before commit 105e10e2cf1c ("kexec_file: drop weak attribute from functions"), there was already no arch-specific implementation of arch_kexec_kernel_verify_sig. With weak attribute dropped by that commit, arch_kexec_kernel_verify_sig is completely useless. So clean it up.

Note later patches are dependent on this patch so it should be backported to the stable tree as well.

Cc: stable@vger.kernel.org Suggested-by: Eric W. Biederman ebiederm@xmission.com Reviewed-by: Michal Suchanek msuchanek@suse.de Acked-by: Baoquan He bhe@redhat.com Signed-off-by: Coiby Xu coxu@redhat.com [zohar@linux.ibm.com: reworded patch description "Note"] Link: https://lore.kernel.org/linux-integrity/20220714134027.394370-1-coxu@redhat.... Signed-off-by: Mimi Zohar zohar@linux.ibm.com Signed-off-by: Michal Suchanek msuchanek@suse.de --- include/linux/kexec.h | 5 ----- kernel/kexec_file.c | 33 +++++++++++++-------------------- 2 files changed, 13 insertions(+), 25 deletions(-)

diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 1638c8d7d216..46f113961dbc 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -206,11 +206,6 @@ static inline void *arch_kexec_kernel_image_load(struct kimage *image) } #endif

-#ifdef CONFIG_KEXEC_SIG -int arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, - unsigned long buf_len); -#endif - extern int kexec_add_buffer(struct kexec_buf *kbuf); int kexec_locate_mem_hole(struct kexec_buf *kbuf);

diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 620021679405..8d73d6d4f0a6 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -81,24 +81,6 @@ int kexec_image_post_load_cleanup_default(struct kimage *image) return image->fops->cleanup(image->image_loader_data); }

-#ifdef CONFIG_KEXEC_SIG -static int kexec_image_verify_sig_default(struct kimage *image, void *buf, - unsigned long buf_len) -{ - if (!image->fops || !image->fops->verify_sig) { - pr_debug("kernel loader does not support signature verification.\n"); - return -EKEYREJECTED; - } - - return image->fops->verify_sig(buf, buf_len); -} - -int arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, unsigned long buf_len) -{ - return kexec_image_verify_sig_default(image, buf, buf_len); -} -#endif - /* * Free up memory used by kernel, initrd, and command line. This is temporary * memory allocation which is not needed any more after these buffers have @@ -141,13 +123,24 @@ void kimage_file_post_load_cleanup(struct kimage *image) }

#ifdef CONFIG_KEXEC_SIG +static int kexec_image_verify_sig(struct kimage *image, void *buf, + unsigned long buf_len) +{ + if (!image->fops || !image->fops->verify_sig) { + pr_debug("kernel loader does not support signature verification.\n"); + return -EKEYREJECTED; + } + + return image->fops->verify_sig(buf, buf_len); +} + static int kimage_validate_signature(struct kimage *image) { int ret;

- ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf, - image->kernel_buf_len); + ret = kexec_image_verify_sig(image, image->kernel_buf, + image->kernel_buf_len); if (ret) {

if (sig_enforce) {

From: Coiby Xu coxu@redhat.com

commit 0d519cadf75184a24313568e7f489a7fc9b1be3b upstream.

Currently, when loading a kernel image via the kexec_file_load() system call, arm64 can only use the .builtin_trusted_keys keyring to verify a signature whereas x86 can use three more keyrings i.e. .secondary_trusted_keys, .machine and .platform keyrings. For example, one resulting problem is kexec'ing a kernel image would be rejected with the error "Lockdown: kexec: kexec of unsigned images is restricted; see man kernel_lockdown.7".

This patch set enables arm64 to make use of the same keyrings as x86 to verify the signature kexec'ed kernel image.

Fixes: 732b7b93d849 ("arm64: kexec_file: add kernel signature verification support") Cc: stable@vger.kernel.org # 105e10e2cf1c: kexec_file: drop weak attribute from functions Cc: stable@vger.kernel.org # 34d5960af253: kexec: clean up arch_kexec_kernel_verify_sig Cc: stable@vger.kernel.org # 83b7bb2d49ae: kexec, KEYS: make the code in bzImage64_verify_sig generic Acked-by: Baoquan He bhe@redhat.com Cc: kexec@lists.infradead.org Cc: keyrings@vger.kernel.org Cc: linux-security-module@vger.kernel.org Co-developed-by: Michal Suchanek msuchanek@suse.de Signed-off-by: Michal Suchanek msuchanek@suse.de Acked-by: Will Deacon will@kernel.org Signed-off-by: Coiby Xu coxu@redhat.com Signed-off-by: Mimi Zohar zohar@linux.ibm.com Signed-off-by: Michal Suchanek msuchanek@suse.de --- arch/arm64/kernel/kexec_image.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c index 9ec34690e255..5ed6a585f21f 100644 --- a/arch/arm64/kernel/kexec_image.c +++ b/arch/arm64/kernel/kexec_image.c @@ -14,7 +14,6 @@ #include <linux/kexec.h> #include <linux/pe.h> #include <linux/string.h> -#include <linux/verification.h> #include <asm/byteorder.h> #include <asm/cpufeature.h> #include <asm/image.h> @@ -130,18 +129,10 @@ static void *image_load(struct kimage *image, return NULL; }

-#ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG -static int image_verify_sig(const char *kernel, unsigned long kernel_len) -{ - return verify_pefile_signature(kernel, kernel_len, NULL, - VERIFYING_KEXEC_PE_SIGNATURE); -} -#endif - const struct kexec_file_ops kexec_image_ops = { .probe = image_probe, .load = image_load, #ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG - .verify_sig = image_verify_sig, + .verify_sig = kexec_kernel_verify_pe_sig, #endif };