Affected: Alpaquita:stream: linux-lts

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

iommu/iova: Fix alloc iova overflows issue

In __alloc_and_insert_iova_range, there is an issue that retry_pfn overflows. The value of iovad->anchor.pfn_hi is ~0UL, then when iovad->cached_node is iovad->anchor, curr_iova->pfn_hi + 1 will overflow. As a result, if the retry logic is executed, low_pfn is updated to 0, and then new_pfn < low_pfn returns false to make the allocation successful.

This issue occurs in the following two situations: 1. The first iova size exceeds the domain size. When initializing iova domain, iovad->cached_node is assigned as iovad->anchor. For example, the iova domain size is 10M, start_pfn is 0x1_F000_0000, and the iova size allocated for the first time is 11M. The following is the log information, new->pfn_lo is smaller than iovad->cached_node.

Example log as follows: [ 223.798112][T1705487] sh: [name:iova&]__alloc_and_insert_iova_range start_pfn:0x1f0000,retry_pfn:0x0,size:0xb00,limit_pfn:0x1f0a00 [ 223.799590][T1705487] sh: [name:iova&]__alloc_and_insert_iova_range success start_pfn:0x1f0000,new->pfn_lo:0x1efe00,new->pfn_hi:0x1f08ff

2. The node with the largest iova->pfn_lo value in the iova domain is deleted, iovad->cached_node will be updated to iovad->anchor, and then the alloc iova size exceeds the maximum iova size that can be allocated in the domain.

After judging that retry_pfn is less than limit_pfn, call retry_pfn+1 to fix the overflow issue.

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

iommu/iova: Fix alloc iova overflows issue

In __alloc_and_insert_iova_range, there is an issue that retry_pfn overflows. The value of iovad->anchor.pfn_hi is ~0UL, then when iovad->cached_node is iovad->anchor, curr_iova->pfn_hi + 1 will overflow. As a result, if the retry logic is executed, low_pfn is updated to 0, and then new_pfn < low_pfn returns false to make the allocation successful.

This issue occurs in the following two situations: 1. The first iova size exceeds the domain size. When initializing iova domain, iovad->cached_node is assigned as iovad->anchor. For example, the iova domain size is 10M, start_pfn is 0x1_F000_0000, and the iova size allocated for the first time is 11M. The following is the log information, new->pfn_lo is smaller than iovad->cached_node.

Example log as follows: [ 223.798112][T1705487] sh: [name:iova&]__alloc_and_insert_iova_range start_pfn:0x1f0000,retry_pfn:0x0,size:0xb00,limit_pfn:0x1f0a00 [ 223.799590][T1705487] sh: [name:iova&]__alloc_and_insert_iova_range success start_pfn:0x1f0000,new->pfn_lo:0x1efe00,new->pfn_hi:0x1f08ff

2. The node with the largest iova->pfn_lo value in the iova domain is deleted, iovad->cached_node will be updated to iovad->anchor, and then the alloc iova size exceeds the maximum iova size that can be allocated in the domain.

After judging that retry_pfn is less than limit_pfn, call retry_pfn+1 to fix the overflow issue.

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 91 more

In the Linux kernel, the following vulnerability has been resolved: iommu/iova: Fix alloc iova overflows issue In __alloc_and_insert_iova_range, there is an issue that retry_pfn overflows. The value of iovad->anchor.pfn_hi is ~0UL, then when iovad->cached_node is iovad->anchor, curr_iova->pfn_hi + 1 will overflow. As a result, if the retry logic is executed, low_pfn is updated to 0, and then new_pfn < low_pfn returns false to make the allocation successful. This issue occurs in the following two situations: 1. The first iova size exceeds the domain size. When initializing iova domain, iovad->cached_node is assigned as iovad->anchor. For example, the iova domain size is 10M, start_pfn is 0x1_F000_0000, and the iova size allocated for the first time is 11M. The following is the log information, new->pfn_lo is smaller than iovad->cached_node. Example log as follows: [ 223.798112][T1705487] sh: [name:iova&]__alloc_and_insert_iova_range start_pfn:0x1f0000,retry_pfn:0x0,size:0xb00,limit_pfn:0x1f0a00 [ 223.799590][T1705487] sh: [name:iova&]__alloc_and_insert_iova_range success start_pfn:0x1f0000,new->pfn_lo:0x1efe00,new->pfn_hi:0x1f08ff 2. The node with the largest iova->pfn_lo value in the iova domain is deleted, iovad->cached_node will be updated to iovad->anchor, and then the alloc iova size exceeds the maximum iova size that can be allocated in the domain. After judging that retry_pfn is less than limit_pfn, call retry_pfn+1 to fix the overflow issue.

Ein lokaler Angreifer kann mehrere Schwachstellen im Linux-Kernel ausnutzen, um einen Denial-of-Service-Zustand zu erzeugen oder einen unspezifischen Angriff durchzuführen.