CVE - CVE-2025-21857

CVE-ID
CVE-2025-21857	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
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
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://git.kernel.org/stable/c/071ed42cff4fcdd89025d966d48eabef59913bf2 URL:https://git.kernel.org/stable/c/071ed42cff4fcdd89025d966d48eabef59913bf2 MISC:https://git.kernel.org/stable/c/3c74b5787caf59bb1e9c5fe0a360643a71eb1e8a URL:https://git.kernel.org/stable/c/3c74b5787caf59bb1e9c5fe0a360643a71eb1e8a MISC:https://git.kernel.org/stable/c/3e4c56cf41876ef2a82f0877fe2a67648f8632b8 URL:https://git.kernel.org/stable/c/3e4c56cf41876ef2a82f0877fe2a67648f8632b8 MISC:https://git.kernel.org/stable/c/de4b679aa3b4da7ec34f639df068b914f20e3c3c URL:https://git.kernel.org/stable/c/de4b679aa3b4da7ec34f639df068b914f20e3c3c
Assigning CNA
kernel.org
Date Record Created
20241229	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20241229)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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