From: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com> stable inclusion from stable-v6.19.6 commit 5366ec7d2f793ce703c403d7fd4c25a3db365b9d category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14784 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 10d1c75ed4382a8e79874379caa2ead8952734f9 ] Patch series "Address page fault in ima_restore_measurement_list()", v3. When the second-stage kernel is booted via kexec with a limiting command line such as "mem=<size>" we observe a pafe fault that happens. BUG: unable to handle page fault for address: ffff97793ff47000 RIP: ima_restore_measurement_list+0xdc/0x45a #PF: error_code(0x0000) not-present page This happens on x86_64 only, as this is already fixed in aarch64 in commit: cbf9c4b9617b ("of: check previous kernel's ima-kexec-buffer against memory bounds") This patch (of 3): When the second-stage kernel is booted with a limiting command line (e.g. "mem=<size>"), the IMA measurement buffer handed over from the previous kernel may fall outside the addressable RAM of the new kernel. Accessing such a buffer can fault during early restore. Introduce a small generic helper, ima_validate_range(), which verifies that a physical [start, end] range for the previous-kernel IMA buffer lies within addressable memory: - On x86, use pfn_range_is_mapped(). - On OF based architectures, use page_is_ram(). Link: https://lkml.kernel.org/r/20251231061609.907170-1-harshit.m.mogalapalli@orac... Link: https://lkml.kernel.org/r/20251231061609.907170-2-harshit.m.mogalapalli@orac... Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Cc: Alexander Graf <graf@amazon.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: guoweikang <guoweikang.kernel@gmail.com> Cc: Henry Willard <henry.willard@oracle.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Bohac <jbohac@suse.cz> Cc: Joel Granados <joel.granados@kernel.org> Cc: Jonathan McDowell <noodles@fb.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Paul Webb <paul.x.webb@oracle.com> Cc: Sohil Mehta <sohil.mehta@intel.com> Cc: Sourabh Jain <sourabhjain@linux.ibm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Yifei Liu <yifei.l.liu@oracle.com> Cc: Baoquan He <bhe@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Conflicts: security/integrity/ima/ima_kexec.c [fix context conflicts] Signed-off-by: Lin Yujun <linyujun809@h-partners.com> Signed-off-by: Liu Mingrui <liumingrui@huawei.com> --- include/linux/ima.h | 1 + security/integrity/ima/ima_kexec.c | 35 ++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/include/linux/ima.h b/include/linux/ima.h index eb119cd62f02..ec860b373109 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -151,6 +151,7 @@ static inline int ima_measure_critical_data(const char *event_label, #ifdef CONFIG_HAVE_IMA_KEXEC int __init ima_free_kexec_buffer(void); int __init ima_get_kexec_buffer(void **addr, size_t *size); +int ima_validate_range(phys_addr_t phys, size_t size); #endif #ifdef CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index ad133fe120db..d7c18d8a3103 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -12,6 +12,8 @@ #include <linux/kexec.h> #include <linux/of.h> #include <linux/ima.h> +#include <linux/mm.h> +#include <linux/overflow.h> #include "ima.h" #ifdef CONFIG_IMA_KEXEC @@ -164,3 +166,36 @@ void __init ima_load_kexec_buffer(void) pr_debug("Error restoring the measurement list: %d\n", rc); } } + +/* + * ima_validate_range - verify a physical buffer lies in addressable RAM + * @phys: physical start address of the buffer from previous kernel + * @size: size of the buffer + * + * On success return 0. On failure returns -EINVAL so callers can skip + * restoring. + */ +int ima_validate_range(phys_addr_t phys, size_t size) +{ + unsigned long start_pfn, end_pfn; + phys_addr_t end_phys; + + if (check_add_overflow(phys, (phys_addr_t)size - 1, &end_phys)) + return -EINVAL; + + start_pfn = PHYS_PFN(phys); + end_pfn = PHYS_PFN(end_phys); + +#ifdef CONFIG_X86 + if (!pfn_range_is_mapped(start_pfn, end_pfn)) +#else + if (!page_is_ram(start_pfn) || !page_is_ram(end_pfn)) +#endif + { + pr_warn("IMA: previous kernel measurement buffer %pa (size 0x%zx) lies outside available memory\n", + &phys, size); + return -EINVAL; + } + + return 0; +} -- 2.34.1