Linux Kernel up to 6.19.3 drm lib/kobject.c devm_add_action_or_reset use after free

Summaryinfo

A vulnerability marked as critical has been reported in Linux Kernel up to 6.19.3. This affects the function devm_add_action_or_reset in the library lib/kobject.c of the component drm. The manipulation leads to use after free. This vulnerability is listed as CVE-2026-46264. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.19.3. This issue affects the function devm_add_action_or_reset in the library lib/kobject.c of the component drm. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: drm/xe/pf: Fix sysfs initialization In case of devm_add_action_or_reset() failure the provided cleanup action will be run immediately on the not yet initialized kobject. This may lead to errors like: [ ] kobject: '(null)' (ff110001393608e0): is not initialized, yet kobject_put() is being called. [ ] WARNING: lib/kobject.c:734 at kobject_put+0xd9/0x250, CPU#0: kworker/0:0/9 [ ] RIP: 0010:kobject_put+0xdf/0x250 [ ] Call Trace: [ ] xe_sriov_pf_sysfs_init+0x21/0x100 [xe] [ ] xe_sriov_pf_init_late+0x87/0x2b0 [xe] [ ] xe_sriov_init_late+0x5f/0x2c0 [xe] [ ] xe_device_probe+0x5f2/0xc20 [xe] [ ] xe_pci_probe+0x396/0x610 [xe] [ ] local_pci_probe+0x47/0xb0 [ ] refcount_t: underflow; use-after-free. [ ] WARNING: lib/refcount.c:28 at refcount_warn_saturate+0x68/0xb0, CPU#0: kworker/0:0/9 [ ] RIP: 0010:refcount_warn_saturate+0x68/0xb0 [ ] Call Trace: [ ] kobject_put+0x174/0x250 [ ] xe_sriov_pf_sysfs_init+0x21/0x100 [xe] [ ] xe_sriov_pf_init_late+0x87/0x2b0 [xe] [ ] xe_sriov_init_late+0x5f/0x2c0 [xe] [ ] xe_device_probe+0x5f2/0xc20 [xe] [ ] xe_pci_probe+0x396/0x610 [xe] [ ] local_pci_probe+0x47/0xb0 Fix that by calling kobject_init() and kobject_add() separately and register cleanup action after the kobject is initialized. Also make this cleanup registration a part of the create helper to fix another mistake, as in the loop we were wrongly passing parent kobject while registering cleanup action, and this resulted in some undetected leaks. (cherry picked from commit 98b16727f07e26a5d4de84d88805ce7ffcfdd324)

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-46264 since 05/13/2026. The exploitation is known to be easy. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 06/03/2026).

Upgrading to version 6.19.4 eliminates this vulnerability. Applying the patch 6ae479b1919ee9bd0560fc7af649932dd420d010/bf7172cd25ed182f30af2cbb9f80c730dc717d8e is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

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