CVE-2023-53843: In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: reject negative ifindex Recent changes in net-next (commit 759ab1edb56c…

PriorityP423medium5.1

EPSS

0.22%

12.1th percentile

In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: reject negative ifindex Recent changes in net-next (commit 759ab1edb56c ("net: store netdevs in an xarray")) refactored the handling of pre-assigned ifindexes and let syzbot surface a latent problem in ovs. ovs does not validate ifindex, making it possible to create netdev ports with negative ifindex values. It's easy to repro with YNL: $ ./cli.py --spec netlink/specs/ovs_datapath.yaml \ --do new \ --json '{"upcall-pid": 1, "name":"my-dp"}' $ ./cli.py --spec netlink/specs/ovs_vport.yaml \ --do new \ --json '{"upcall-pid": "00000001", "name": "some-port0", "dp-ifindex":3,"ifindex":4294901760,"type":2}' $ ip link show -65536: some-port0: mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether 7a:48:21:ad:0b:fb brd ff:ff:ff:ff:ff:ff ... Validate the inputs. Now the second command correctly returns: $ ./cli.py --spec netlink/specs/ovs_vport.yaml \ --do new \ --json '{"upcall-pid": "00000001", "name": "some-port0", "dp-ifindex":3,"ifindex":4294901760,"type":2}' lib.ynl.NlError: Netlink error: Numerical result out of range nl_len = 108 (92) nl_flags = 0x300 nl_type = 2 error: -34 extack: {'msg': 'integer out of range', 'unknown': [[type:4 len:36] b'\x0c\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x03\x00\xff\xff\xff\x7f\x00\x00\x00\x00\x08\x00\x01\x00\x08\x00\x00\x00'], 'bad-attr': '.ifindex'} Accept 0 since it used to be silently ignored.

Affected

10 ranges

Vendor	Product	Version range	Fixed in
debian	linux	< linux 6.1.52-1 (bookworm)	linux 6.1.52-1 (bookworm)
linux	linux	—	—
linux	linux	>= 54c4ef34c4b6f9720fded620e2893894f9f2c554 < c965a58376146dcfdda186819462e8eb3aadef3a	c965a58376146dcfdda186819462e8eb3aadef3a
linux	linux	>= 54c4ef34c4b6f9720fded620e2893894f9f2c554 < 881faff9e548a7ddfb11595be7c1c649217d27db	881faff9e548a7ddfb11595be7c1c649217d27db
linux	linux	>= 54c4ef34c4b6f9720fded620e2893894f9f2c554 < a552bfa16bab4ce901ee721346a28c4e483f4066	a552bfa16bab4ce901ee721346a28c4e483f4066
linux	linux_kernel	>= 0 < 6.1.52-1	6.1.52-1
linux	linux_kernel	>= 0 < 6.4.13-1	6.4.13-1
linux	linux_kernel	>= 0 < 6.4.13-1	6.4.13-1
linux	linux_kernel	>= 6.1.0 < 6.1.47	6.1.47
linux	linux_kernel	>= 6.2.0 < 6.4.12	6.4.12

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