CVE-2025-21857 (GCVE-0-2025-21857)
Vulnerability from cvelistv5
Published
2025-03-12 09:42
Modified
2026-05-11 21:07
Severity ?
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_api: fix error handling causing NULL dereference tcf_exts_miss_cookie_base_alloc() calls xa_alloc_cyclic() which can return 1 if the allocation succeeded after wrapping. This was treated as an error, with value 1 returned to caller tcf_exts_init_ex() which sets exts->actions to NULL and returns 1 to caller fl_change(). fl_change() treats err == 1 as success, calling tcf_exts_validate_ex() which calls tcf_action_init() with exts->actions as argument, where it is dereferenced. Example trace: BUG: kernel NULL pointer dereference, address: 0000000000000000 CPU: 114 PID: 16151 Comm: handler114 Kdump: loaded Not tainted 5.14.0-503.16.1.el9_5.x86_64 #1 RIP: 0010:tcf_action_init+0x1f8/0x2c0 Call Trace: tcf_action_init+0x1f8/0x2c0 tcf_exts_validate_ex+0x175/0x190 fl_change+0x537/0x1120 [cls_flower]
References
Impacted products
Vendor Product Version
Linux Linux Version: 80cd22c35c9001fe72bf614d29439de41933deca
Version: 80cd22c35c9001fe72bf614d29439de41933deca
Version: 80cd22c35c9001fe72bf614d29439de41933deca
Version: 80cd22c35c9001fe72bf614d29439de41933deca
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