Medium 5.5Published Apr 22, 2026

CVE-2026-31434btrfs: fix leak of kobject name for sub-group space_info

Updated under an hour ago (Oct 27, 2026, 6:10 AM ET)

Does this affect you?

It affects Linux and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for Linux

Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix leak of kobject name for sub-group space_info When create_space_info_sub_group() allocates elements of space_info->sub_group[], kobject_init_and_add() is called for each element via btrfs_sysfs_add_space_info_type(). However, when check_removing_space_info() frees these elements, it does not call btrfs_sysfs_remove_space_info() on them. As a result, kobject_put() is not called and the associated kobj->name objects are leaked. This memory leak is reproduced by running the blktests test case zbd/009 on kernels built with CONFIG_DEBUG_KMEMLEAK. The kmemleak feature reports the following error: unreferenced object 0xffff888112877d40 (size 16): comm "mount", pid 1244, jiffies 4294996972 hex dump (first 16 bytes): 64 61 74 61 2d 72 65 6c 6f 63 00 c4 c6 a7 cb 7f data-reloc...... backtrace (crc 53ffde4d): __kmalloc_node_track_caller_noprof+0x619/0x870 kstrdup+0x42/0xc0 kobject_set_name_vargs+0x44/0x110 kobject_init_and_add+0xcf/0x150 btrfs_sysfs_add_space_info_type+0xfc/0x210 [btrfs] create_space_info_sub_group.constprop.0+0xfb/0x1b0 [btrfs] create_space_info+0x211/0x320 [btrfs] btrfs_init_space_info+0x15a/0x1b0 [btrfs] open_ctree+0x33c7/0x4a50 [btrfs] btrfs_get_tree.cold+0x9f/0x1ee [btrfs] vfs_get_tree+0x87/0x2f0 vfs_cmd_create+0xbd/0x280 __do_sys_fsconfig+0x3df/0x990 do_syscall_64+0x136/0x1540 entry_SYSCALL_64_after_hwframe+0x76/0x7e To avoid the leak, call btrfs_sysfs_remove_space_info() instead of kfree() for the elements.

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: May 23, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 64c7ddda83acfbaa0efb381a1928ce908c584607 before 416484f21a9d1280cf6daa7ebc10c79b59c46e48; from 0bd151ce4200ca847990e05cca29a76456982ca5 before 94054ffd311a1f76b7093ba8ebf50bdb0d28337c; from 190d5a7c4fe42b8c9aa46e3336389e7cb10395bb before 1737ddeafbb1304f41ec2eede4f7366082e7c96a; from f92ee31e031c7819126d2febdda0c3e91f5d2eb9 before 3c844d01f9874a43004c82970d8da94f9aba8949; from f92ee31e031c7819126d2febdda0c3e91f5d2eb9 before 3c645c6f7e5470debbb81666b230056de48f36dc; from f92ee31e031c7819126d2febdda0c3e91f5d2eb9 before a4376d9a5d4c9610e69def3fc0b32c86a7ab7a41; from 6.1.162 before 6.1.168; from 6.6.122 before 6.6.131; and 1 more ranges	CNA record
linux linux_kernel linux:linux_kernel	from 6.1.162 before 6.1.168; from 6.6.122 before 6.6.131; from 6.12.67 before 6.12.80; from 6.16 before 6.18.21; from 6.19 before 6.19.11; 7.0; 7.0; 7.0; and 3 more ranges	NVD

References

References

https://git.kernel.org/stable/c/416484f21a9d1280cf6daa7ebc10c79b59c46e48	patch
https://git.kernel.org/stable/c/94054ffd311a1f76b7093ba8ebf50bdb0d28337c	patch
https://git.kernel.org/stable/c/1737ddeafbb1304f41ec2eede4f7366082e7c96a	patch
https://git.kernel.org/stable/c/3c844d01f9874a43004c82970d8da94f9aba8949	patch
https://git.kernel.org/stable/c/3c645c6f7e5470debbb81666b230056de48f36dc	patch
https://git.kernel.org/stable/c/a4376d9a5d4c9610e69def3fc0b32c86a7ab7a41	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.