ALT-PU-2025-15228-3

Package update kernel-image-6.12 in branch c10f2

Version6.12.59-alt0.c10f.2

Published2026-02-28

Max severityMEDIUM

Severity:

Closed issues (3)

MEDIUM4.4

Уязвимость функции nf_tables_updchain компонента net/netfilter/nf_tables_api.c ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

Published: 2025-12-11Modified: 2026-04-14

CVSS 3.xMEDIUM 4.4

CVSS:3.x/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

CVSS 2.0MEDIUM 4.6

CVSS:2.0/AV:L/AC:L/Au:S/C:N/I:N/A:C

References

CVE-2025-38678

MEDIUM5.5

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: reject duplicate device on updates A chain/flowtable update with duplicated devices in the same batch is possible. Unfortunately, netdev event path only removes the first device that is found, leaving unregistered the hook of the duplicated device. Check if a duplicated device exists in the transaction batch, bail out with EEXIST in such case. WARNING is hit when unregistering the hook: [49042.221275] WARNING: CPU: 4 PID: 8425 at net/netfilter/core.c:340 nf_hook_entry_head+0xaa/0x150 [49042.221375] CPU: 4 UID: 0 PID: 8425 Comm: nft Tainted: G S 6.16.0+ #170 PREEMPT(full) [...] [49042.221382] RIP: 0010:nf_hook_entry_head+0xaa/0x150

Published: 2025-09-03Modified: 2025-12-06

CVSS 3.xMEDIUM 5.5

CVSS:3.x/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

MEDIUM5.5

In the Linux kernel, the following vulnerability has been resolved: ksm: use range-walk function to jump over holes in scan_get_next_rmap_item Currently, scan_get_next_rmap_item() walks every page address in a VMA to locate mergeable pages. This becomes highly inefficient when scanning large virtual memory areas that contain mostly unmapped regions, causing ksmd to use large amount of cpu without deduplicating much pages. This patch replaces the per-address lookup with a range walk using walk_page_range(). The range walker allows KSM to skip over entire unmapped holes in a VMA, avoiding unnecessary lookups. This problem was previously discussed in [1]. Consider the following test program which creates a 32 TiB mapping in the virtual address space but only populates a single page: #include #include #include /* 32 TiB / const size_t size = 32ul 1024 * 1024 * 1024 * 1024; int main() { char area = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_NORESERVE | MAP_PRIVATE | MAP_ANON, -1, 0); if (area == MAP_FAILED) { perror("mmap() failed\n"); return -1; } / Populate a single page such that we get an anon_vma. / area = 0; /* Enable KSM. */ madvise(area, size, MADV_MERGEABLE); pause(); return 0; } $ ./ksm-sparse & $ echo 1 > /sys/kernel/mm/ksm/run Without this patch ksmd uses 100% of the cpu for a long time (more then 1 hour in my test machine) scanning all the 32 TiB virtual address space that contain only one mapped page. This makes ksmd essentially deadlocked not able to deduplicate anything of value. With this patch ksmd walks only the one mapped page and skips the rest of the 32 TiB virtual address space, making the scan fast using little cpu.

Published: 2025-12-16Modified: 2026-02-26

CVSS 3.xMEDIUM 5.5

CVSS:3.x/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References