CVE-2025-71134
Publication date:
14/01/2026
In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
mm/page_alloc: change all pageblocks migrate type on coalescing<br />
<br />
When a page is freed it coalesces with a buddy into a higher order page<br />
while possible. When the buddy page migrate type differs, it is expected<br />
to be updated to match the one of the page being freed.<br />
<br />
However, only the first pageblock of the buddy page is updated, while the<br />
rest of the pageblocks are left unchanged.<br />
<br />
That causes warnings in later expand() and other code paths (like below),<br />
since an inconsistency between migration type of the list containing the<br />
page and the page-owned pageblocks migration types is introduced.<br />
<br />
[ 308.986589] ------------[ cut here ]------------<br />
[ 308.987227] page type is 0, passed migratetype is 1 (nr=256)<br />
[ 308.987275] WARNING: CPU: 1 PID: 5224 at mm/page_alloc.c:812 expand+0x23c/0x270<br />
[ 308.987293] Modules linked in: algif_hash(E) af_alg(E) nft_fib_inet(E) nft_fib_ipv4(E) nft_fib_ipv6(E) nft_fib(E) nft_reject_inet(E) nf_reject_ipv4(E) nf_reject_ipv6(E) nft_reject(E) nft_ct(E) nft_chain_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) nf_tables(E) s390_trng(E) vfio_ccw(E) mdev(E) vfio_iommu_type1(E) vfio(E) sch_fq_codel(E) drm(E) i2c_core(E) drm_panel_orientation_quirks(E) loop(E) nfnetlink(E) vsock_loopback(E) vmw_vsock_virtio_transport_common(E) vsock(E) ctcm(E) fsm(E) diag288_wdt(E) watchdog(E) zfcp(E) scsi_transport_fc(E) ghash_s390(E) prng(E) aes_s390(E) des_generic(E) des_s390(E) libdes(E) sha3_512_s390(E) sha3_256_s390(E) sha_common(E) paes_s390(E) crypto_engine(E) pkey_cca(E) pkey_ep11(E) zcrypt(E) rng_core(E) pkey_pckmo(E) pkey(E) autofs4(E)<br />
[ 308.987439] Unloaded tainted modules: hmac_s390(E):2<br />
[ 308.987650] CPU: 1 UID: 0 PID: 5224 Comm: mempig_verify Kdump: loaded Tainted: G E 6.18.0-gcc-bpf-debug #431 PREEMPT<br />
[ 308.987657] Tainted: [E]=UNSIGNED_MODULE<br />
[ 308.987661] Hardware name: IBM 3906 M04 704 (z/VM 7.3.0)<br />
[ 308.987666] Krnl PSW : 0404f00180000000 00000349976fa600 (expand+0x240/0x270)<br />
[ 308.987676] R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:3 PM:0 RI:0 EA:3<br />
[ 308.987682] Krnl GPRS: 0000034980000004 0000000000000005 0000000000000030 000003499a0e6d88<br />
[ 308.987688] 0000000000000005 0000034980000005 000002be803ac000 0000023efe6c8300<br />
[ 308.987692] 0000000000000008 0000034998d57290 000002be00000100 0000023e00000008<br />
[ 308.987696] 0000000000000000 0000000000000000 00000349976fa5fc 000002c99b1eb6f0<br />
[ 308.987708] Krnl Code: 00000349976fa5f0: c020008a02f2 larl %r2,000003499883abd4<br />
00000349976fa5f6: c0e5ffe3f4b5 brasl %r14,0000034997378f60<br />
#00000349976fa5fc: af000000 mc 0,0<br />
>00000349976fa600: a7f4ff4c brc 15,00000349976fa498<br />
00000349976fa604: b9040026 lgr %r2,%r6<br />
00000349976fa608: c0300088317f larl %r3,0000034998800906<br />
00000349976fa60e: c0e5fffdb6e1 brasl %r14,00000349976b13d0<br />
00000349976fa614: af000000 mc 0,0<br />
[ 308.987734] Call Trace:<br />
[ 308.987738] [] expand+0x240/0x270<br />
[ 308.987744] ([] expand+0x23c/0x270)<br />
[ 308.987749] [] rmqueue_bulk+0x71e/0x940<br />
[ 308.987754] [] __rmqueue_pcplist+0x1fe/0x2a0<br />
[ 308.987759] [] rmqueue.isra.0+0xb46/0xf40<br />
[ 308.987763] [] get_page_from_freelist+0x198/0x8d0<br />
[ 308.987768] [] __alloc_frozen_pages_noprof+0x198/0x400<br />
[ 308.987774] [] alloc_pages_mpol+0xb8/0x220<br />
[ 308.987781] [] folio_alloc_mpol_noprof+0x26/0xc0<br />
[ 308.987786] [] vma_alloc_folio_noprof+0x6c/0xa0<br />
[ 308.987791] [] vma_alloc_anon_folio_pmd+0x42/0x240<br />
[ 308.987799] [] __do_huge_pmd_anonymous_page+0x3a/0x210<br />
[ 308.987804] [
Severity CVSS v4.0: Pending analysis
Last modification:
14/01/2026