2.6 KiB
CVE-2024-56717
Description
In the Linux kernel, the following vulnerability has been resolved:net: mscc: ocelot: fix incorrect IFH SRC_PORT field in ocelot_ifh_set_basic()Packets injected by the CPU should have a SRC_PORT field equal to theCPU port module index in the Analyzer block (ocelot->num_phys_ports).The blamed commit copied the ocelot_ifh_set_basic() call incorrectlyfrom ocelot_xmit_common() in net/dsa/tag_ocelot.c. Instead of callingwith "x", it calls with BIT_ULL(x), but the field is not a port mask,but rather a single port index.[ side note: this is the technical debt of code duplication :( ]The error used to be silent and doesn't appear to have otheruser-visible manifestations, but with new changes in the packinglibrary, it now fails loudly as follows:------------[ cut here ]------------Cannot store 0x40 inside bits 46-43 - will truncatesja1105 spi2.0: xmit timed outWARNING: CPU: 1 PID: 102 at lib/packing.c:98 __pack+0x90/0x198sja1105 spi2.0: timed out polling for tstampCPU: 1 UID: 0 PID: 102 Comm: felix_xmitTainted: G W N 6.13.0-rc1-00372-gf706b85d972d-dirty #2605Call trace: __pack+0x90/0x198 (P) __pack+0x90/0x198 (L) packing+0x78/0x98 ocelot_ifh_set_basic+0x260/0x368 ocelot_port_inject_frame+0xa8/0x250 felix_port_deferred_xmit+0x14c/0x258 kthread_worker_fn+0x134/0x350 kthread+0x114/0x138The code path pertains to the ocelot switchdev driver and to the felixsecondary DSA tag protocol, ocelot-8021q. Here seen with ocelot-8021q.The messenger (packing) is not really to blame, so fix the originalcommit instead.
POC
Reference
No PoCs from references.