发布于3月6日3月6日 Members SUSE: CVE-2023-52843: SUSE Linux Security Advisory Severity 4 CVSS (AV:L/AC:M/Au:N/C:P/I:P/A:P) Published 05/21/2024 Created 08/16/2024 Added 08/09/2024 Modified 08/28/2024 Description In the Linux kernel, the following vulnerability has been resolved: llc: verify mac len before reading mac header LLC reads the mac header with eth_hdr without verifying that the skb has an Ethernet header. Syzbot was able to enter llc_rcv on a tun device. Tun can insert packets without mac len and with user configurable skb->protocol (passing a tun_pi header when not configuring IFF_NO_PI). BUG: KMSAN: uninit-value in llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline] BUG: KMSAN: uninit-value in llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111 llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline] llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111 llc_rcv+0xc5d/0x14a0 net/llc/llc_input.c:218 __netif_receive_skb_one_core net/core/dev.c:5523 [inline] __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5637 netif_receive_skb_internal net/core/dev.c:5723 [inline] netif_receive_skb+0x58/0x660 net/core/dev.c:5782 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555 tun_get_user+0x54c5/0x69c0 drivers/net/tun.c:2002 Add a mac_len test before all three eth_hdr(skb) calls under net/llc. There are further uses in include/net/llc_pdu.h. All these are protected by a test skb->protocol == ETH_P_802_2. Which does not protect against this tun scenario. But the mac_len test added in this patch in llc_fixup_skb will indirectly protect those too. That is called from llc_rcv before any other LLC code. It is tempting to just add a blanket mac_len check in llc_rcv, but not sure whether that could break valid LLC paths that do not assume an Ethernet header. 802.2 LLC may be used on top of non-802.3 protocols in principle. The below referenced commit shows that used to, on top of Token Ring. At least one of the three eth_hdr uses goes back to before the start of git history. But the one that syzbot exercises is introduced in this commit. That commit is old enough (2008), that effectively all stable kernels should receive this. Solution(s) suse-upgrade-cluster-md-kmp-64kb suse-upgrade-cluster-md-kmp-azure suse-upgrade-cluster-md-kmp-default suse-upgrade-cluster-md-kmp-rt suse-upgrade-dlm-kmp-64kb suse-upgrade-dlm-kmp-azure suse-upgrade-dlm-kmp-default suse-upgrade-dlm-kmp-rt suse-upgrade-dtb-allwinner suse-upgrade-dtb-altera suse-upgrade-dtb-amazon suse-upgrade-dtb-amd suse-upgrade-dtb-amlogic suse-upgrade-dtb-apm suse-upgrade-dtb-apple suse-upgrade-dtb-arm suse-upgrade-dtb-broadcom suse-upgrade-dtb-cavium suse-upgrade-dtb-exynos suse-upgrade-dtb-freescale suse-upgrade-dtb-hisilicon suse-upgrade-dtb-lg suse-upgrade-dtb-marvell suse-upgrade-dtb-mediatek suse-upgrade-dtb-nvidia suse-upgrade-dtb-qcom suse-upgrade-dtb-renesas suse-upgrade-dtb-rockchip suse-upgrade-dtb-socionext suse-upgrade-dtb-sprd suse-upgrade-dtb-xilinx suse-upgrade-gfs2-kmp-64kb suse-upgrade-gfs2-kmp-azure suse-upgrade-gfs2-kmp-default suse-upgrade-gfs2-kmp-rt suse-upgrade-kernel-64kb suse-upgrade-kernel-64kb-devel suse-upgrade-kernel-64kb-extra suse-upgrade-kernel-64kb-livepatch-devel suse-upgrade-kernel-64kb-optional suse-upgrade-kernel-azure suse-upgrade-kernel-azure-base suse-upgrade-kernel-azure-devel suse-upgrade-kernel-azure-extra suse-upgrade-kernel-azure-livepatch-devel suse-upgrade-kernel-azure-optional suse-upgrade-kernel-azure-vdso suse-upgrade-kernel-debug suse-upgrade-kernel-debug-devel suse-upgrade-kernel-debug-livepatch-devel suse-upgrade-kernel-debug-vdso suse-upgrade-kernel-default suse-upgrade-kernel-default-base suse-upgrade-kernel-default-base-rebuild suse-upgrade-kernel-default-devel suse-upgrade-kernel-default-extra suse-upgrade-kernel-default-livepatch suse-upgrade-kernel-default-livepatch-devel suse-upgrade-kernel-default-man suse-upgrade-kernel-default-optional suse-upgrade-kernel-default-vdso suse-upgrade-kernel-devel suse-upgrade-kernel-devel-azure suse-upgrade-kernel-devel-rt suse-upgrade-kernel-docs suse-upgrade-kernel-docs-html suse-upgrade-kernel-kvmsmall suse-upgrade-kernel-kvmsmall-devel suse-upgrade-kernel-kvmsmall-livepatch-devel suse-upgrade-kernel-kvmsmall-vdso suse-upgrade-kernel-macros suse-upgrade-kernel-obs-build suse-upgrade-kernel-obs-qa suse-upgrade-kernel-rt suse-upgrade-kernel-rt-devel suse-upgrade-kernel-rt-extra suse-upgrade-kernel-rt-livepatch suse-upgrade-kernel-rt-livepatch-devel suse-upgrade-kernel-rt-optional suse-upgrade-kernel-rt-vdso suse-upgrade-kernel-rt_debug suse-upgrade-kernel-rt_debug-devel suse-upgrade-kernel-rt_debug-livepatch-devel suse-upgrade-kernel-rt_debug-vdso suse-upgrade-kernel-source suse-upgrade-kernel-source-azure suse-upgrade-kernel-source-rt suse-upgrade-kernel-source-vanilla suse-upgrade-kernel-syms suse-upgrade-kernel-syms-azure suse-upgrade-kernel-syms-rt suse-upgrade-kernel-zfcpdump suse-upgrade-kselftests-kmp-64kb suse-upgrade-kselftests-kmp-azure suse-upgrade-kselftests-kmp-default suse-upgrade-kselftests-kmp-rt suse-upgrade-ocfs2-kmp-64kb suse-upgrade-ocfs2-kmp-azure suse-upgrade-ocfs2-kmp-default suse-upgrade-ocfs2-kmp-rt suse-upgrade-reiserfs-kmp-64kb suse-upgrade-reiserfs-kmp-azure suse-upgrade-reiserfs-kmp-default suse-upgrade-reiserfs-kmp-rt References https://attackerkb.com/topics/cve-2023-52843 CVE - 2023-52843
