pktgen: Avoid out-of-bounds access in get_imix_entries

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: pktgen: Avoid out-of-bounds access in get_imix_entries Passing a sufficient amount of imix entries leads to invalid access to the pkt_dev->imix_entries array because of the incorrect boundary check. UBSAN: array-index-out-of-bounds in net/core/pktgen.c:874:24 index 20 is out of range for type 'imix_pkt [20]' CPU: 2 PID: 1210 Comm: bash Not tainted 6.10.0-rc1 #121 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) Call Trace: <TASK> dump_stack_lvl lib/dump_stack.c:117 __ubsan_handle_out_of_bounds lib/ubsan.c:429 get_imix_entries net/core/pktgen.c:874 pktgen_if_write net/core/pktgen.c:1063 pde_write fs/proc/inode.c:334 proc_reg_write fs/proc/inode.c:346 vfs_write fs/read_write.c:593 ksys_write fs/read_write.c:644 do_syscall_64 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe arch/x86/entry/entry_64.S:130 Found by Linux Verification Center (linuxtesting.org) with SVACE. [ fp: allow to fill the array completely; minor changelog cleanup ]

References

• https://git.kernel.org/stable/c/3450092cc2d1c311c5ea92a2486daa2a33520ea5
• https://git.kernel.org/stable/c/e5d24a7074dcd0c7e76b7e7e4efbbe7418d62486
• https://git.kernel.org/stable/c/7cde21f52042aa2e29a654458166b873d2ae66b3
• https://git.kernel.org/stable/c/1a9b65c672ca9dc4ba52ca2fd54329db9580ce29
• https://git.kernel.org/stable/c/76201b5979768500bca362871db66d77cb4c225e