In the Linux kernel, the following vulnerability has been resolved: net: ethernet: mtk_wed: fix use-after-free panic in mtk_wed_setup_tc_block_cb() When there are multiple ap interfaces on one band and with WED on, turning the interface down will cause a kernel panic on MT798X. Previously, cb_priv was freed in mtk_wed_setup_tc_block() without marking NULL,and mtk_wed_setup_tc_block_cb() didn't check the value, too. Assign NULL after free cb_priv in mtk_wed_setup_tc_block() and check NULL in mtk_wed_setup_tc_block_cb(). ---------- Unable to handle kernel paging request at virtual address 0072460bca32b4f5 Call trace: mtk_wed_setup_tc_block_cb+0x4/0x38 0xffffffc0794084bc tcf_block_playback_offloads+0x70/0x1e8 tcf_block_unbind+0x6c/0xc8 ... ---------
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.