In the Linux kernel, the following vulnerability has been resolved:

arm64: mte: Avoid setting PG_mte_tagged if no tags cleared or restored

Prior to commit 69e3b846d8a7 ("arm64: mte: Sync tags for pages where PTE is untagged"), mte_sync_tags() was only called for pte_tagged() entries (those mapped with PROT_MTE). Therefore mte_sync_tags() could safely use test_and_set_bit(PG_mte_tagged, &page->flags) without inadvertently setting PG_mte_tagged on an untagged page.

The above commit was required as guests may enable MTE without any control at the stage 2 mapping, nor a PROT_MTE mapping in the VMM. However, the side-effect was that any page with a PTE that looked like swap (or migration) was getting PG_mte_tagged set automatically. A subsequent page copy (e.g. migration) copied the tags to the destination page even if the tags were owned by KASAN.

This issue was masked by the page_kasan_tag_reset() call introduced in commit e5b8d9218951 ("arm64: mte: reset the page tag in page->flags"). When this commit was reverted (20794545c146), KASAN started reporting access faults because the overriding tags in a page did not match the original page->flags (with CONFIG_KASAN_HW_TAGS=y):

BUG: KASAN: invalid-access in copy_page+0x10/0xd0 arch/arm64/lib/copy_page.S:26 Read at addr f5ff000017f2e000 by task syz-executor.1/2218 Pointer tag: [f5], memory tag: [f2]

Move the PG_mte_tagged bit setting from mte_sync_tags() to the actual place where tags are cleared (mte_sync_page_tags()) o…

In the Linux kernel, the following vulnerability has been resolved:

arm64: mte: Avoid setting PG_mte_tagged if no tags cleared or restored

Prior to commit 69e3b846d8a7 ("arm64: mte: Sync tags for pages where PTE is untagged"), mte_sync_tags() was only called for pte_tagged() entries (those mapped with PROT_MTE). Therefore mte_sync_tags() could safely use test_and_set_bit(PG_mte_tagged, &page->flags) without inadvertently setting PG_mte_tagged on an untagged page.

The above commit was required as guests may enable MTE without any control at the stage 2 mapping, nor a PROT_MTE mapping in the VMM. However, the side-effect was that any page with a PTE that looked like swap (or migration) was getting PG_mte_tagged set automatically. A subsequent page copy (e.g. migration) copied the tags to the destination page even if the tags were owned by KASAN.

This issue was masked by the page_kasan_tag_reset() call introduced in commit e5b8d9218951 ("arm64: mte: reset the page tag in page->flags"). When this commit was reverted (20794545c146), KASAN started reporting access faults because the overriding tags in a page did not match the original page->flags (with CONFIG_KASAN_HW_TAGS=y):

BUG: KASAN: invalid-access in copy_page+0x10/0xd0 arch/arm64/lib/copy_page.S:26 Read at addr f5ff000017f2e000 by task syz-executor.1/2218 Pointer tag: [f5], memory tag: [f2]

Move the PG_mte_tagged bit setting from mte_sync_tags() to the actual place where tags are cleared (mte_sync_page_tags()) o…

kernel: seg6: fix the iif in the IPv6 socket control block Kernel: race when faulting a device private page in memory manager kernel: use-after-free in l1oip timer handlers kernel: Rate limit overflow messages in r8152 in intr_callback kernel: vmwgfx: use-after-free in vmw_cmd_res_check kernel: vmwgfx: use-after-free in vmw_execbuf_tie_context hw: Intel: Gather Data Sampling (GDS) side channel vulnerability kernel: Information leak in l2cap_parse_conf_req in net/bluetooth/l2cap_core.c kernel: perf: Fix perf_pending_task() UaF kernel: gpiolib: fix memory leak in gpiochip_setup_dev() kernel: memcg: fix possible use-after-free in memcg_write_event_control() kernel: mm/khugepaged: invoke MMU notifiers in shmem/file collapse paths kernel: char: tpm: Protect tpm_pm_suspend with locks kernel: ixgbevf: Fix resource leak in ixgbevf_init_module() kernel: dax: make sure inodes are flushed before destroy cache kernel: watch_queue: Actually free the watch kernel: watch_queue: Fix NULL dereference in error cleanup kernel: rtc: pl031: fix rtc features null pointer dereference kernel: tpm: fix reference counting for struct tpm_chip kernel: NFSv4: Don't hold the layoutget locks across multiple RPC calls kernel: xprtrdma: treat all calls not a bcall when bc_serv is NULL kernel: net: ipv6: unexport __init-annotated seg6_hmac_init() kernel: af_unix: Fix a data-race in unix_dgram_peer_wake_me(). kernel: regulator: scmi: Fix refcount leak in scmi_regulator_probe kernel: mm/mempolicy: fix uninit-v…

Security update for the Linux Kernel

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 105 more

In the Linux kernel, the following vulnerability has been resolved: arm64: mte: Avoid setting PG_mte_tagged if no tags cleared or restored Prior to commit 69e3b846d8a7 ("arm64: mte: Sync tags for pages where PTE is untagged"), mte_sync_tags() was only called for pte_tagged() entries (those mapped with PROT_MTE). Therefore mte_sync_tags() could safely use test_and_set_bit(PG_mte_tagged, &page->flags) without inadvertently setting PG_mte_tagged on an untagged page. The above commit was required as guests may enable MTE without any control at the stage 2 mapping, nor a PROT_MTE mapping in the VMM. However, the side-effect was that any page with a PTE that looked like swap (or migration) was getting PG_mte_tagged set automatically. A subsequent page copy (e.g. migration) copied the tags to the destination page even if the tags were owned by KASAN. This issue was masked by the page_kasan_tag_reset() call introduced in commit e5b8d9218951 ("arm64: mte: reset the page tag in page->flags"). When this commit was reverted (20794545c146), KASAN started reporting access faults because the overriding tags in a page did not match the original page->flags (with CONFIG_KASAN_HW_TAGS=y): BUG: KASAN: invalid-access in copy_page+0x10/0xd0 arch/arm64/lib/copy_page.S:26 Read at addr f5ff000017f2e000 by task syz-executor.1/2218 Pointer tag: [f5], memory tag: [f2] Move the PG_mte_tagged bit setting from mte_sync_tags() to the actual place where tags are cleared (mte_sync_page_tags()) or rest…

Ein lokaler Angreifer kann mehrere Schwachstellen in Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen.