CVE-2025-38059 [Medium] | Security Vulnerability in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: btrfs: avoid NULL pointer dereference if no valid csum tree [BUG] When trying read-only scrub on a btrfs with rescue=idatacsums mount option, it will crash with the following call trace: BUG: kernel NULL pointer dereference, address: 0000000000000208 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page CPU: 1 UID: 0 PID: 835 Comm: btrfs Tainted: G O 6.15.0-rc3-custom+ #236 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022 RIP: 0010:btrfs_lookup_csums_bitmap+0x49/0x480 [btrfs] Call Trace: <TASK> scrub_find_fill_first_stripe+0x35b/0x3d0 [btrfs] scrub_simple_mirror+0x175/0x290 [btrfs] scrub_stripe+0x5f7/0x6f0 [btrfs] scrub_chunk+0x9a/0x150 [btrfs] scrub_enumerate_chunks+0x333/0x660 [btrfs] btrfs_scrub_dev+0x23e/0x600 [btrfs] btrfs_ioctl+0x1dcf/0x2f80 [btrfs] __x64_sys_ioctl+0x97/0xc0 do_syscall_64+0x4f/0x120 entry_SYSCALL_64_after_hwframe+0x76/0x7e [CAUSE] Mount option "rescue=idatacsums" will completely skip loading the csum tree, so that any data read will not find any data csum thus we will ignore data checksum verification. Normally call sites utilizing csum tree will check the fs state flag NO_DATA_CSUMS bit, but unfortunately scrub does not check that bit at all. This results in scrub to call btrfs_search_slot() on a NULL pointer and triggered above crash. [FIX] Check both extent and csum tree root before doing any tree search.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-04-14	0.02%	0.07%	+0.05%
2	2025-06-18	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-04-14

0.02%

0.07%

+0.05%

2025-06-18

—

0.02%

—

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]

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]

OS Trackers for CVE-2025-38059

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2025-38059 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2.	https://security-tracker.debian.org/tracker/CVE-2025-38059
`redhat`	—	—	https://access.redhat.com/security/cve/CVE-2025-38059
`suse`	medium	—	https://www.suse.com/security/cve/CVE-2025-38059/
`ubuntu`	medium	CVE-2025-38059 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, ignored 168, released 137, needed 77, not-affected 21, needs-triage 2, pending 1.	https://ubuntu.com/security/CVE-2025-38059

Affected software / configurations for CVE-2025-38059

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 5.9, < 6.6.93	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.7, < 6.12.31	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.13, < 6.14.9	cpe:2.3:o:linux:linux_kernel::::::::
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::::::
linux	linux_kernel	6.15	cpe:2.3:o:linux:linux_kernel:6.15:rc3::::::
linux	linux_kernel	6.15	cpe:2.3:o:linux:linux_kernel:6.15:rc4::::::
linux	linux_kernel	6.15	cpe:2.3:o:linux:linux_kernel:6.15:rc5::::::

References for CVE-2025-38059

URL	Tags
https://git.kernel.org/stable/c/50d0de59f66cbe6d597481e099bf1c70fd07e0a9	Patch
https://git.kernel.org/stable/c/6e9770de024964b1017f99ee94f71967bd6edaeb	Patch
https://git.kernel.org/stable/c/d35bed14b0bc95c6845863a3744ecd10b888c830	Patch
https://git.kernel.org/stable/c/f95d186255b319c48a365d47b69bd997fecb674e	Patch

URL

CVE-2025-38059 | btrfs: avoid NULL pointer dereference if no valid csum tree

Exploit prediction scoring system (EPSS) score for CVE-2025-38059

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38059

Weakness enumeration for CVE-2025-38059

OS Trackers for CVE-2025-38059

Affected software / configurations for CVE-2025-38059

References for CVE-2025-38059