In the Linux kernel, the following vulnerability has been resolved: net:emac/emac-mac: Fix a use after free in emac_mac_tx_buf_send In emac_mac_tx_buf_send, it calls emac_tx_fill_tpd(..,skb,..). If some error happens in emac_tx_fill_tpd(), the skb will be freed via dev_kfree_skb(skb) in error branch of emac_tx_fill_tpd(). But the freed skb is still used via skb->len by netdev_sent_queue(,skb->len). As i observed that emac_tx_fill_tpd() haven't modified the value of skb->len, thus my patch assigns skb->len to 'len' before the possible free and use 'len' instead of skb->len later.
In the Linux kernel, the following vulnerability has been resolved: net:emac/emac-mac: Fix a use after free in emac_mac_tx_buf_send In emac_mac_tx_buf_send, it calls emac_tx_fill_tpd(..,skb,..). If some error happens in emac_tx_fill_tpd(), the skb will be freed via dev_kfree_skb(skb) in error branch of emac_tx_fill_tpd(). But the freed skb is still used via skb->len by netdev_sent_queue(,skb->len). As i observed that emac_tx_fill_tpd() haven't modified the value of skb->len, thus my patch assigns skb->len to 'len' before the possible free and use 'len' instead of skb->len later.
Linux Linux, linux kernel의 현재 전체 버전이 공식 영향 범위(Linux Linux, linux kernel >= b9b17debc69d27cd55e21ee51a5ba7fc50a426cf < c7f75d11fe72913d2619f97b2334b083cd7bb955, >= b9b17debc69d27cd55e21ee51a5ba7fc50a426cf < dc1b438a35773d030be0ee80d9c635c3e558a322, >= b9b17debc69d27cd55e21ee51a5ba7fc50a426cf < 16d8c44be52e3650917736d45f5904384a9da834, >= b9b17debc69d27cd55e21ee51a5ba7fc50a426cf < 55fcdd1258faaecca74b91b88cc0921f9edd775d, >= b9b17debc69d27cd55e21ee51a5ba7fc50a426cf < 9dc373f74097edd0e35f3393d6248eda8d1ba99d, >= b9b17debc69d27cd55e21ee51a5ba7fc50a426cf < 8c06f34785068b87e2b560534c77c163d6c6dca7, >= b9b17debc69d27cd55e21ee51a5ba7fc50a426cf < e407495ba6788a67d1bd41714158c079e340879b, >= b9b17debc69d27cd55e21ee51a5ba7fc50a426cf < 6d72e7c767acbbdd44ebc7d89c6690b405b32b57, >= 4.9, >= 4.9 < 4.9.269, >= 4.10 < 4.14.233, >= 4.15 < 4.19.191, >= 4.20 < 5.4.119, >= 5.5 < 5.10.37, >= 5.11 < 5.11.21, >= 5.12 < 5.12.4)에 포함되는지 확인합니다. OS를 선택하면 해당 OS의 제품·패키지·KB·APAR 확인 명령만 표시됩니다.
조치방안
구조화된 수정 버전 값(4.9.269, 4.14.233, 4.19.191, 5.4.119, 5.10.37, 5.11.21, 5.12.4)은 참고용입니다. 공급사 공식 보안 권고에서 제품·에디션·설치 방식별 수정 기준을 확인한 뒤 적용합니다.
조치 후 확인사항
패치 후 같은 명령으로 전체 버전을 다시 확인해 Linux Linux, linux kernel 4.9.269, 4.14.233, 4.19.191, 5.4.119, 5.10.37, 5.11.21, 5.12.4 기준을 충족하는지 확인합니다. 이어서 메모리 손상 관련 오류·공격 흔적이 새로 발생하지 않는지 확인합니다.
