CVE-2025-37779 | lib/iov_iter: fix to increase non slab folio refcount

In the Linux kernel, the following vulnerability has been resolved: lib/iov_iter: fix to increase non slab folio refcount When testing EROFS file-backed mount over v9fs on qemu, I encountered a folio UAF issue. The page sanity check reports the following call trace. The root cause is that pages in bvec are coalesced across a folio bounary. The refcount of all non-slab folios should be increased to ensure p9_releas_pages can put them correctly. BUG: Bad page state in process md5sum pfn:18300 page: refcount:0 mapcount:0 mapping:00000000d5ad8e4e index:0x60 pfn:0x18300 head: order:0 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 aops:z_erofs_aops ino:30b0f dentry name(?):"GoogleExtServicesCn.apk" flags: 0x100000000000041(locked|head|node=0|zone=1) raw: 0100000000000041 dead000000000100 dead000000000122 ffff888014b13bd0 raw: 0000000000000060 0000000000000020 00000000ffffffff 0000000000000000 head: 0100000000000041 dead000000000100 dead000000000122 ffff888014b13bd0 head: 0000000000000060 0000000000000020 00000000ffffffff 0000000000000000 head: 0100000000000000 0000000000000000 ffffffffffffffff 0000000000000000 head: 0000000000000010 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set Call Trace: dump_stack_lvl+0x53/0x70 bad_page+0xd4/0x220 __free_pages_ok+0x76d/0xf30 __folio_put+0x230/0x320 p9_release_pages+0x179/0x1f0 p9_virtio_zc_request+0xa2a/0x1230 p9_client_zc_rpc.constprop.0+0x247/0x700 p9_client_read_once+0x34d/0x810 p9_client_read+0xf3/0x150 v9fs_issue_read+0x111/0x360 netfs_unbuffered_read_iter_locked+0x927/0x1390 netfs_unbuffered_read_iter+0xa2/0xe0 vfs_iocb_iter_read+0x2c7/0x460 erofs_fileio_rq_submit+0x46b/0x5b0 z_erofs_runqueue+0x1203/0x21e0 z_erofs_readahead+0x579/0x8b0 read_pages+0x19f/0xa70 page_cache_ra_order+0x4ad/0xb80 filemap_readahead.isra.0+0xe7/0x150 filemap_get_pages+0x7aa/0x1890 filemap_read+0x320/0xc80 vfs_read+0x6c6/0xa30 ksys_read+0xf9/0x1c0 do_syscall_64+0x9e/0x1a0 entry_SYSCALL_64_after_hwframe+0x71/0x79

Published: 2025-05-01 Last update: 2025-11-06 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-37779 is rated Low Risk (29.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.07%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-37779

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-25 0.02% 0.07% +0.06%
2 2025-05-02 — 0.02% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-37779

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]

Weakness enumeration for CVE-2025-37779

OS Trackers for CVE-2025-37779

vendor priority summary link
debian unimportant CVE-2025-37779 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2025-37779
redhat — — https://access.redhat.com/security/cve/CVE-2025-37779
suse medium CVE-2025-37779 severity moderate: SUSE including 52 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 290 product×package rows across 52 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Linux Enterprise High Availability Extension 15 SP7, … (52 product lines)): Known Not Affected 264, Fixed 26. https://www.suse.com/security/cve/CVE-2025-37779/
ubuntu medium CVE-2025-37779 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, not-affected 158, ignored 147, released 99, needs-triage 2. https://ubuntu.com/security/CVE-2025-37779

Affected software / configurations for CVE-2025-37779

Vendor Product Version Raw CPE
linux linux_kernel >= 6.14.1, < 6.14.4 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 6.14 cpe:2.3:o:linux:linux_kernel:6.14:-:*:*:*:*:*:*
linux linux_kernel 6.15 cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:*
linux linux_kernel 6.15 cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:*

References for CVE-2025-37779

cvelogic Threat Intelligence