In the Linux kernel, the following vulnerability has been resolved:
mm/slub: avoid zeroing outside-object freepointer for single free
Commit 284f17ac13fe (mm/slub: handle bulk and single object freeing separately) splits single and bulk object freeing in two functions slab_free() and slab_free_bulk() which leads slab_free() to call slab_free_hook() directly instead of slab_free_freelist_hook().
If init_on_free
is set, slab_free_hook() zeroes the object.
Afterward, if slub_debug=F
and CONFIG_SLAB_FREELIST_HARDENED
are
set, the do_slab_free() slowpath executes freelist consistency
checks and try to decode a zeroed freepointer which leads to a
Freepointer corrupt detection in check_object().
During bulk free, slab_free_freelist_hook() isnt affected as it always
sets it objects freepointer using set_freepointer() to maintain its
reconstructed freelist after init_on_free
.
For single free, objects freepointer thus needs to be avoided when
stored outside the object if init_on_free
is set. The freepointer left
as is, check_object() may later detect an invalid pointer value due to
objects overflow.
To reproduce, set slub_debug=FU init_on_free=1 log_level=7
on the
command line of a kernel build with CONFIG_SLAB_FREELIST_HARDENED=y
.
dmesg sample log: [ 10.708715] ============================================================================= [ 10.710323] BUG kmalloc-rnd-05-32 (Tainted: G B T ): Freepointer corrupt [ 10.712695] —————————————————————————– [ 10.712695] [ 10.712695] Slab 0xffffd8bdc400d580 objects=32 used=4 fp=0xffff9d9a80356f80 flags=0x200000000000a00(workingset|slab|node=0|zone=2) [ 10.716698] Object 0xffff9d9a80356600 @offset=1536 fp=0x7ee4f480ce0ecd7c [ 10.716698] [ 10.716698] Bytes b4 ffff9d9a803565f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ……………. [ 10.720703] Object ffff9d9a80356600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ……………. [ 10.720703] Object ffff9d9a80356610: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ……………. [ 10.724696] Padding ffff9d9a8035666c: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ……………. [ 10.724696] Padding ffff9d9a8035667c: 00 00 00 00 …. [ 10.724696] FIX kmalloc-rnd-05-32: Object at 0xffff9d9a80356600 not freed
Name | Vendor | Start Version | End Version |
---|---|---|---|
Linux | Ubuntu | devel | * |
Linux | Ubuntu | noble | * |
Linux | Ubuntu | upstream | * |
Linux-allwinner-5.19 | Ubuntu | jammy | * |
Linux-allwinner-5.19 | Ubuntu | upstream | * |
Linux-aws | Ubuntu | devel | * |
Linux-aws | Ubuntu | noble | * |
Linux-aws | Ubuntu | upstream | * |
Linux-aws-5.0 | Ubuntu | esm-infra/bionic | * |
Linux-aws-5.0 | Ubuntu | upstream | * |
Linux-aws-5.11 | Ubuntu | focal | * |
Linux-aws-5.11 | Ubuntu | upstream | * |
Linux-aws-5.13 | Ubuntu | focal | * |
Linux-aws-5.13 | Ubuntu | upstream | * |
Linux-aws-5.15 | Ubuntu | upstream | * |
Linux-aws-5.19 | Ubuntu | jammy | * |
Linux-aws-5.19 | Ubuntu | upstream | * |
Linux-aws-5.3 | Ubuntu | esm-infra/bionic | * |
Linux-aws-5.3 | Ubuntu | upstream | * |
Linux-aws-5.4 | Ubuntu | upstream | * |
Linux-aws-5.8 | Ubuntu | focal | * |
Linux-aws-5.8 | Ubuntu | upstream | * |
Linux-aws-6.2 | Ubuntu | jammy | * |
Linux-aws-6.2 | Ubuntu | upstream | * |
Linux-aws-6.5 | Ubuntu | upstream | * |
Linux-aws-fips | Ubuntu | upstream | * |
Linux-aws-hwe | Ubuntu | upstream | * |
Linux-azure | Ubuntu | devel | * |
Linux-azure | Ubuntu | esm-infra/bionic | * |
Linux-azure | Ubuntu | noble | * |
Linux-azure | Ubuntu | upstream | * |
Linux-azure-4.15 | Ubuntu | upstream | * |
Linux-azure-5.11 | Ubuntu | focal | * |
Linux-azure-5.11 | Ubuntu | upstream | * |
Linux-azure-5.13 | Ubuntu | focal | * |
Linux-azure-5.13 | Ubuntu | upstream | * |
Linux-azure-5.15 | Ubuntu | upstream | * |
Linux-azure-5.19 | Ubuntu | jammy | * |
Linux-azure-5.19 | Ubuntu | upstream | * |
Linux-azure-5.3 | Ubuntu | esm-infra/bionic | * |
Linux-azure-5.3 | Ubuntu | upstream | * |
Linux-azure-5.4 | Ubuntu | upstream | * |
Linux-azure-5.8 | Ubuntu | focal | * |
Linux-azure-5.8 | Ubuntu | upstream | * |
Linux-azure-6.2 | Ubuntu | jammy | * |
Linux-azure-6.2 | Ubuntu | upstream | * |
Linux-azure-6.5 | Ubuntu | upstream | * |
Linux-azure-edge | Ubuntu | esm-infra/bionic | * |
Linux-azure-edge | Ubuntu | upstream | * |
Linux-azure-fde | Ubuntu | focal | * |
Linux-azure-fde | Ubuntu | upstream | * |
Linux-azure-fde-5.15 | Ubuntu | upstream | * |
Linux-azure-fde-5.19 | Ubuntu | jammy | * |
Linux-azure-fde-5.19 | Ubuntu | upstream | * |
Linux-azure-fde-6.2 | Ubuntu | jammy | * |
Linux-azure-fde-6.2 | Ubuntu | upstream | * |
Linux-azure-fips | Ubuntu | upstream | * |
Linux-bluefield | Ubuntu | upstream | * |
Linux-fips | Ubuntu | upstream | * |
Linux-gcp | Ubuntu | devel | * |
Linux-gcp | Ubuntu | esm-infra/bionic | * |
Linux-gcp | Ubuntu | noble | * |
Linux-gcp | Ubuntu | upstream | * |
Linux-gcp-4.15 | Ubuntu | upstream | * |
Linux-gcp-5.11 | Ubuntu | focal | * |
Linux-gcp-5.11 | Ubuntu | upstream | * |
Linux-gcp-5.13 | Ubuntu | focal | * |
Linux-gcp-5.13 | Ubuntu | upstream | * |
Linux-gcp-5.15 | Ubuntu | upstream | * |
Linux-gcp-5.19 | Ubuntu | jammy | * |
Linux-gcp-5.19 | Ubuntu | upstream | * |
Linux-gcp-5.3 | Ubuntu | esm-infra/bionic | * |
Linux-gcp-5.3 | Ubuntu | upstream | * |
Linux-gcp-5.4 | Ubuntu | upstream | * |
Linux-gcp-5.8 | Ubuntu | focal | * |
Linux-gcp-5.8 | Ubuntu | upstream | * |
Linux-gcp-6.2 | Ubuntu | jammy | * |
Linux-gcp-6.2 | Ubuntu | upstream | * |
Linux-gcp-6.5 | Ubuntu | upstream | * |
Linux-gcp-fips | Ubuntu | upstream | * |
Linux-gke | Ubuntu | devel | * |
Linux-gke | Ubuntu | focal | * |
Linux-gke | Ubuntu | noble | * |
Linux-gke | Ubuntu | upstream | * |
Linux-gke-4.15 | Ubuntu | esm-infra/bionic | * |
Linux-gke-4.15 | Ubuntu | upstream | * |
Linux-gke-5.15 | Ubuntu | focal | * |
Linux-gke-5.15 | Ubuntu | upstream | * |
Linux-gke-5.4 | Ubuntu | esm-infra/bionic | * |
Linux-gke-5.4 | Ubuntu | upstream | * |
Linux-gkeop | Ubuntu | upstream | * |
Linux-gkeop-5.15 | Ubuntu | upstream | * |
Linux-gkeop-5.4 | Ubuntu | esm-infra/bionic | * |
Linux-gkeop-5.4 | Ubuntu | upstream | * |
Linux-hwe | Ubuntu | esm-infra/bionic | * |
Linux-hwe | Ubuntu | upstream | * |
Linux-hwe-5.11 | Ubuntu | focal | * |
Linux-hwe-5.11 | Ubuntu | upstream | * |
Linux-hwe-5.13 | Ubuntu | focal | * |
Linux-hwe-5.13 | Ubuntu | upstream | * |
Linux-hwe-5.15 | Ubuntu | upstream | * |
Linux-hwe-5.19 | Ubuntu | jammy | * |
Linux-hwe-5.19 | Ubuntu | upstream | * |
Linux-hwe-5.4 | Ubuntu | upstream | * |
Linux-hwe-5.8 | Ubuntu | focal | * |
Linux-hwe-5.8 | Ubuntu | upstream | * |
Linux-hwe-6.2 | Ubuntu | jammy | * |
Linux-hwe-6.2 | Ubuntu | upstream | * |
Linux-hwe-6.5 | Ubuntu | upstream | * |
Linux-hwe-edge | Ubuntu | esm-infra/bionic | * |
Linux-hwe-edge | Ubuntu | esm-infra/xenial | * |
Linux-hwe-edge | Ubuntu | upstream | * |
Linux-ibm | Ubuntu | devel | * |
Linux-ibm | Ubuntu | mantic | * |
Linux-ibm | Ubuntu | noble | * |
Linux-ibm | Ubuntu | upstream | * |
Linux-ibm-5.15 | Ubuntu | upstream | * |
Linux-ibm-5.4 | Ubuntu | upstream | * |
Linux-intel | Ubuntu | noble | * |
Linux-intel | Ubuntu | upstream | * |
Linux-intel-5.13 | Ubuntu | focal | * |
Linux-intel-5.13 | Ubuntu | upstream | * |
Linux-intel-iotg | Ubuntu | upstream | * |
Linux-intel-iotg-5.15 | Ubuntu | upstream | * |
Linux-iot | Ubuntu | upstream | * |
Linux-kvm | Ubuntu | upstream | * |
Linux-laptop | Ubuntu | upstream | * |
Linux-lowlatency | Ubuntu | devel | * |
Linux-lowlatency | Ubuntu | noble | * |
Linux-lowlatency | Ubuntu | upstream | * |
Linux-lowlatency-hwe-5.15 | Ubuntu | upstream | * |
Linux-lowlatency-hwe-5.19 | Ubuntu | jammy | * |
Linux-lowlatency-hwe-5.19 | Ubuntu | upstream | * |
Linux-lowlatency-hwe-6.2 | Ubuntu | jammy | * |
Linux-lowlatency-hwe-6.2 | Ubuntu | upstream | * |
Linux-lowlatency-hwe-6.5 | Ubuntu | upstream | * |
Linux-lts-xenial | Ubuntu | upstream | * |
Linux-nvidia | Ubuntu | noble | * |
Linux-nvidia | Ubuntu | upstream | * |
Linux-nvidia-6.2 | Ubuntu | jammy | * |
Linux-nvidia-6.2 | Ubuntu | upstream | * |
Linux-nvidia-6.5 | Ubuntu | upstream | * |
Linux-nvidia-6.8 | Ubuntu | jammy | * |
Linux-nvidia-lowlatency | Ubuntu | noble | * |
Linux-oem | Ubuntu | esm-infra/bionic | * |
Linux-oem | Ubuntu | upstream | * |
Linux-oem-5.10 | Ubuntu | focal | * |
Linux-oem-5.10 | Ubuntu | upstream | * |
Linux-oem-5.13 | Ubuntu | focal | * |
Linux-oem-5.13 | Ubuntu | upstream | * |
Linux-oem-5.14 | Ubuntu | focal | * |
Linux-oem-5.14 | Ubuntu | upstream | * |
Linux-oem-5.17 | Ubuntu | jammy | * |
Linux-oem-5.17 | Ubuntu | upstream | * |
Linux-oem-5.6 | Ubuntu | focal | * |
Linux-oem-5.6 | Ubuntu | upstream | * |
Linux-oem-6.0 | Ubuntu | jammy | * |
Linux-oem-6.0 | Ubuntu | upstream | * |
Linux-oem-6.1 | Ubuntu | jammy | * |
Linux-oem-6.1 | Ubuntu | upstream | * |
Linux-oem-6.5 | Ubuntu | upstream | * |
Linux-oem-6.8 | Ubuntu | noble | * |
Linux-oem-6.8 | Ubuntu | upstream | * |
Linux-oracle | Ubuntu | devel | * |
Linux-oracle | Ubuntu | noble | * |
Linux-oracle | Ubuntu | upstream | * |
Linux-oracle-5.0 | Ubuntu | esm-infra/bionic | * |
Linux-oracle-5.0 | Ubuntu | upstream | * |
Linux-oracle-5.11 | Ubuntu | focal | * |
Linux-oracle-5.11 | Ubuntu | upstream | * |
Linux-oracle-5.13 | Ubuntu | focal | * |
Linux-oracle-5.13 | Ubuntu | upstream | * |
Linux-oracle-5.15 | Ubuntu | upstream | * |
Linux-oracle-5.3 | Ubuntu | esm-infra/bionic | * |
Linux-oracle-5.3 | Ubuntu | upstream | * |
Linux-oracle-5.4 | Ubuntu | upstream | * |
Linux-oracle-5.8 | Ubuntu | focal | * |
Linux-oracle-5.8 | Ubuntu | upstream | * |
Linux-oracle-6.5 | Ubuntu | upstream | * |
Linux-raspi | Ubuntu | devel | * |
Linux-raspi | Ubuntu | noble | * |
Linux-raspi | Ubuntu | upstream | * |
Linux-raspi-5.4 | Ubuntu | upstream | * |
Linux-raspi2 | Ubuntu | focal | * |
Linux-raspi2 | Ubuntu | upstream | * |
Linux-riscv | Ubuntu | devel | * |
Linux-riscv | Ubuntu | focal | * |
Linux-riscv | Ubuntu | jammy | * |
Linux-riscv | Ubuntu | noble | * |
Linux-riscv | Ubuntu | upstream | * |
Linux-riscv-5.11 | Ubuntu | focal | * |
Linux-riscv-5.11 | Ubuntu | upstream | * |
Linux-riscv-5.15 | Ubuntu | upstream | * |
Linux-riscv-5.19 | Ubuntu | jammy | * |
Linux-riscv-5.19 | Ubuntu | upstream | * |
Linux-riscv-5.8 | Ubuntu | focal | * |
Linux-riscv-5.8 | Ubuntu | upstream | * |
Linux-riscv-6.5 | Ubuntu | upstream | * |
Linux-starfive | Ubuntu | upstream | * |
Linux-starfive-5.19 | Ubuntu | jammy | * |
Linux-starfive-5.19 | Ubuntu | upstream | * |
Linux-starfive-6.2 | Ubuntu | jammy | * |
Linux-starfive-6.2 | Ubuntu | upstream | * |
Linux-starfive-6.5 | Ubuntu | upstream | * |
Linux-xilinx-zynqmp | Ubuntu | upstream | * |