cbcvebase.
CVE-2025-21857
published 2025-03-12

CVE-2025-21857: In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_api: fix error handling causing NULL dereference…

PriorityP418medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.21%
11.7th percentile
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]

Affected

15 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.12.17-1 (forky)linux 6.12.17-1 (forky)
linuxlinux
linuxlinux>= 80cd22c35c9001fe72bf614d29439de41933deca < de4b679aa3b4da7ec34f639df068b914f20e3c3cde4b679aa3b4da7ec34f639df068b914f20e3c3c
linuxlinux>= 80cd22c35c9001fe72bf614d29439de41933deca < 3e4c56cf41876ef2a82f0877fe2a67648f8632b83e4c56cf41876ef2a82f0877fe2a67648f8632b8
linuxlinux>= 80cd22c35c9001fe72bf614d29439de41933deca < 3c74b5787caf59bb1e9c5fe0a360643a71eb1e8a3c74b5787caf59bb1e9c5fe0a360643a71eb1e8a
linuxlinux>= 80cd22c35c9001fe72bf614d29439de41933deca < 071ed42cff4fcdd89025d966d48eabef59913bf2071ed42cff4fcdd89025d966d48eabef59913bf2
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.12.17-16.12.17-1
linuxlinux_kernel>= 0 < 6.12.17-16.12.17-1
linuxlinux_kernel>= 0 < 6.8.0-78.786.8.0-78.78
linuxlinux_kernel>= 6.13 < 6.13.56.13.5
linuxlinux_kernel>= 6.3 < 6.6.806.6.80
linuxlinux_kernel>= 6.7 < 6.12.176.12.17
msrcazl3_kernel_6.6.78.1-3_on_azure_linux_3.0
msrcazl3_kernel_6.6.82.1-1_on_azure_linux_3.0

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5LOW
vendor_msrc5.5MEDIUM
vendor_redhat5.5MEDIUM
vendor_ubuntu5.5MEDIUM
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