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author | 2023-10-30 19:09:55 -1000 | |
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committer | 2023-10-30 19:09:55 -1000 | |
commit | befaa609f4c784f505c02ea3ff036adf4f4aa814 (patch) | |
tree | 310a29484cda62f7cb19fb07f4c3cd7c1b87c5f2 /kernel | |
parent | Merge tag 'slab-for-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/vba... (diff) | |
parent | hwmon: (acpi_power_meter) replace open-coded kmemdup_nul (diff) | |
download | linux-befaa609f4c784f505c02ea3ff036adf4f4aa814.tar.gz linux-befaa609f4c784f505c02ea3ff036adf4f4aa814.tar.bz2 linux-befaa609f4c784f505c02ea3ff036adf4f4aa814.zip |
Merge tag 'hardening-v6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening updates from Kees Cook:
"One of the more voluminous set of changes is for adding the new
__counted_by annotation[1] to gain run-time bounds checking of
dynamically sized arrays with UBSan.
- Add LKDTM test for stuck CPUs (Mark Rutland)
- Improve LKDTM selftest behavior under UBSan (Ricardo Cañuelo)
- Refactor more 1-element arrays into flexible arrays (Gustavo A. R.
Silva)
- Analyze and replace strlcpy and strncpy uses (Justin Stitt, Azeem
Shaikh)
- Convert group_info.usage to refcount_t (Elena Reshetova)
- Add __counted_by annotations (Kees Cook, Gustavo A. R. Silva)
- Add Kconfig fragment for basic hardening options (Kees Cook, Lukas
Bulwahn)
- Fix randstruct GCC plugin performance mode to stay in groups (Kees
Cook)
- Fix strtomem() compile-time check for small sources (Kees Cook)"
* tag 'hardening-v6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (56 commits)
hwmon: (acpi_power_meter) replace open-coded kmemdup_nul
reset: Annotate struct reset_control_array with __counted_by
kexec: Annotate struct crash_mem with __counted_by
virtio_console: Annotate struct port_buffer with __counted_by
ima: Add __counted_by for struct modsig and use struct_size()
MAINTAINERS: Include stackleak paths in hardening entry
string: Adjust strtomem() logic to allow for smaller sources
hardening: x86: drop reference to removed config AMD_IOMMU_V2
randstruct: Fix gcc-plugin performance mode to stay in group
mailbox: zynqmp: Annotate struct zynqmp_ipi_pdata with __counted_by
drivers: thermal: tsens: Annotate struct tsens_priv with __counted_by
irqchip/imx-intmux: Annotate struct intmux_data with __counted_by
KVM: Annotate struct kvm_irq_routing_table with __counted_by
virt: acrn: Annotate struct vm_memory_region_batch with __counted_by
hwmon: Annotate struct gsc_hwmon_platform_data with __counted_by
sparc: Annotate struct cpuinfo_tree with __counted_by
isdn: kcapi: replace deprecated strncpy with strscpy_pad
isdn: replace deprecated strncpy with strscpy
NFS/flexfiles: Annotate struct nfs4_ff_layout_segment with __counted_by
nfs41: Annotate struct nfs4_file_layout_dsaddr with __counted_by
...
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/configs/hardening.config | 98 | ||||
-rw-r--r-- | kernel/cred.c | 2 | ||||
-rw-r--r-- | kernel/groups.c | 2 |
3 files changed, 100 insertions, 2 deletions
diff --git a/kernel/configs/hardening.config b/kernel/configs/hardening.config new file mode 100644 index 000000000000..95a400f042b1 --- /dev/null +++ b/kernel/configs/hardening.config @@ -0,0 +1,98 @@ +# Help: Basic kernel hardening options +# +# These are considered the basic kernel hardening, self-protection, and +# attack surface reduction options. They are expected to have low (or +# no) performance impact on most workloads, and have a reasonable level +# of legacy API removals. + +# Make sure reporting of various hardening actions is possible. +CONFIG_BUG=y + +# Basic kernel memory permission enforcement. +CONFIG_STRICT_KERNEL_RWX=y +CONFIG_STRICT_MODULE_RWX=y +CONFIG_VMAP_STACK=y + +# Kernel image and memory ASLR. +CONFIG_RANDOMIZE_BASE=y +CONFIG_RANDOMIZE_MEMORY=y + +# Randomize allocator freelists, harden metadata. +CONFIG_SLAB_FREELIST_RANDOM=y +CONFIG_SLAB_FREELIST_HARDENED=y +CONFIG_SHUFFLE_PAGE_ALLOCATOR=y +CONFIG_RANDOM_KMALLOC_CACHES=y + +# Randomize kernel stack offset on syscall entry. +CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT=y + +# Basic stack frame overflow protection. +CONFIG_STACKPROTECTOR=y +CONFIG_STACKPROTECTOR_STRONG=y + +# Basic buffer length bounds checking. +CONFIG_HARDENED_USERCOPY=y +CONFIG_FORTIFY_SOURCE=y + +# Basic array index bounds checking. +CONFIG_UBSAN=y +CONFIG_UBSAN_TRAP=y +CONFIG_UBSAN_BOUNDS=y +# CONFIG_UBSAN_SHIFT is not set +# CONFIG_UBSAN_DIV_ZERO +# CONFIG_UBSAN_UNREACHABLE +# CONFIG_UBSAN_BOOL +# CONFIG_UBSAN_ENUM +# CONFIG_UBSAN_ALIGNMENT +CONFIG_UBSAN_SANITIZE_ALL=y + +# Linked list integrity checking. +CONFIG_LIST_HARDENED=y + +# Initialize all heap variables to zero on allocation. +CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y + +# Initialize all stack variables to zero on function entry. +CONFIG_INIT_STACK_ALL_ZERO=y + +# Wipe RAM at reboot via EFI. For more details, see: +# https://trustedcomputinggroup.org/resource/pc-client-work-group-platform-reset-attack-mitigation-specification/ +# https://bugzilla.redhat.com/show_bug.cgi?id=1532058 +CONFIG_RESET_ATTACK_MITIGATION=y + +# Disable DMA between EFI hand-off and the kernel's IOMMU setup. +CONFIG_EFI_DISABLE_PCI_DMA=y + +# Force IOMMU TLB invalidation so devices will never be able to access stale +# data content. +CONFIG_IOMMU_SUPPORT=y +CONFIG_IOMMU_DEFAULT_DMA_STRICT=y + +# Do not allow direct physical memory access to non-device memory. +CONFIG_STRICT_DEVMEM=y +CONFIG_IO_STRICT_DEVMEM=y + +# Provide userspace with seccomp BPF API for syscall attack surface reduction. +CONFIG_SECCOMP=y +CONFIG_SECCOMP_FILTER=y + +# Provides some protections against SYN flooding. +CONFIG_SYN_COOKIES=y + +# Attack surface reduction: do not autoload TTY line disciplines. +# CONFIG_LDISC_AUTOLOAD is not set + +# Dangerous; enabling this disables userspace brk ASLR. +# CONFIG_COMPAT_BRK is not set + +# Dangerous; exposes kernel text image layout. +# CONFIG_PROC_KCORE is not set + +# Dangerous; enabling this disables userspace VDSO ASLR. +# CONFIG_COMPAT_VDSO is not set + +# Attack surface reduction: Use the modern PTY interface (devpts) only. +# CONFIG_LEGACY_PTYS is not set + +# Attack surface reduction: Use only modesetting video drivers. +# CONFIG_DRM_LEGACY is not set diff --git a/kernel/cred.c b/kernel/cred.c index 98cb4eca23fb..4dc0b27b5462 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -36,7 +36,7 @@ do { \ static struct kmem_cache *cred_jar; /* init to 2 - one for init_task, one to ensure it is never freed */ -static struct group_info init_groups = { .usage = ATOMIC_INIT(2) }; +static struct group_info init_groups = { .usage = REFCOUNT_INIT(2) }; /* * The initial credentials for the initial task diff --git a/kernel/groups.c b/kernel/groups.c index 9aaed2a31073..9b43da22647d 100644 --- a/kernel/groups.c +++ b/kernel/groups.c @@ -19,7 +19,7 @@ struct group_info *groups_alloc(int gidsetsize) if (!gi) return NULL; - atomic_set(&gi->usage, 1); + refcount_set(&gi->usage, 1); gi->ngroups = gidsetsize; return gi; } |