AL2023 kernel changes from Amazon Linux 1 (AL1) - Amazon Linux 2023
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AL2023 kernel changes from Amazon Linux 1 (AL1)

Kernel Live Patching

Both AL2023 and AL2 add support for kernel live-patching functionality. This allows you to patch critical and important security vulnerabilities in the Linux kernel without reboot or downtime. For more information, see Kernel Live Patching on AL2023.

Kernel file system support

There have been several changes in the file systems that the kernel in AL1 will support mounting, along with changes in the partitioning schemes that the kernel will parse.

CONFIG option AL1/4.14/x86_64 AL2023/6.1/aarch64 AL2023/6.1/x86_64 AL2023/6.12/aarch64 AL2023/6.12/x86_64
CONFIG_AFS_FS m n n n n
CONFIG_AF_RXRPC m n n n n
CONFIG_BSD_DISKLABEL y n n n n
CONFIG_CRAMFS m n n n n
CONFIG_CRAMFS_BLOCKDEV N/A N/A N/A N/A N/A
CONFIG_DM_CLONE N/A n n n n
CONFIG_DM_ERA n n n n n
CONFIG_DM_INTEGRITY m m m m m
CONFIG_DM_LOG_WRITES n m m m m
CONFIG_DM_SWITCH n n n n n
CONFIG_DM_VERITY n n n n n
CONFIG_ECRYPT_FS m n n n n
CONFIG_EXFAT_FS N/A m m m m
CONFIG_EXT2_FS m n n n n
CONFIG_EXT3_FS m n n n n
CONFIG_GFS2_FS n n n n n
CONFIG_HFSPLUS_FS m n n n n
CONFIG_HFS_FS m n n n n
CONFIG_JFS_FS n n n n n
CONFIG_LDM_PARTITION y n n n n
CONFIG_MAC_PARTITION y n n n n
CONFIG_NFS_V2 m n n n n
CONFIG_NTFS_FS m n n n n
CONFIG_ROMFS_FS m n n n n
CONFIG_SOLARIS_X86_PARTITION y n n n n
CONFIG_SQUASHFS_ZSTD y y y y y
CONFIG_SUN_PARTITION y n n n n

Security focused kernel config changes

CONFIG option AL1/4.14/x86_64 AL2023/6.1/aarch64 AL2023/6.1/x86_64 AL2023/6.12/aarch64 AL2023/6.12/x86_64
CONFIG_BUG_ON_DATA_CORRUPTION y y y y y
CONFIG_DEFAULT_MMAP_MIN_ADDR 4096 65536 65536 65536 65536
CONFIG_DEVMEM y n n n n
CONFIG_DEVPORT y n n n n
CONFIG_FORTIFY_SOURCE y y y y y
CONFIG_HARDENED_USERCOPY_FALLBACK N/A N/A N/A N/A N/A
CONFIG_INIT_ON_ALLOC_DEFAULT_ON N/A n n n n
CONFIG_INIT_ON_FREE_DEFAULT_ON N/A n n n n
CONFIG_IOMMU_DEFAULT_DMA_STRICT N/A n n n n
CONFIG_LDISC_AUTOLOAD y n n n n
CONFIG_SCHED_CORE N/A N/A y N/A y
CONFIG_SCHED_STACK_END_CHECK y y y y y
CONFIG_SECURITY_DMESG_RESTRICT n y y y y
CONFIG_SECURITY_SELINUX_DISABLE y n n N/A N/A
CONFIG_SHUFFLE_PAGE_ALLOCATOR N/A y y y y
CONFIG_SLAB_FREELIST_HARDENED y y y y y
CONFIG_SLAB_FREELIST_RANDOM n y y y y

Other kernel configuration changes

CONFIG option AL1/4.14/x86_64 AL2023/6.1/aarch64 AL2023/6.1/x86_64 AL2023/6.12/aarch64 AL2023/6.12/x86_64
CONFIG_HZ 250 100 100 100 100
CONFIG_NR_CPUS 8192 4096 8192 4096 8192
CONFIG_PANIC_ON_OOPS n y y y y
CONFIG_PANIC_ON_OOPS_VALUE 0 1 1 1 1
CONFIG_PPP m n n n n
CONFIG_SLIP m n n n n
CONFIG_XEN_PV y N/A n N/A n