{"id":"AZL-48297","summary":"CVE-2024-38538 affecting package kernel for versions less than 5.15.176.3-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: xmit: make sure we have at least eth header len bytes\n\nsyzbot triggered an uninit value[1] error in bridge device's xmit path\nby sending a short (less than ETH_HLEN bytes) skb. To fix it check if\nwe can actually pull that amount instead of assuming.\n\nTested with dropwatch:\n drop at: br_dev_xmit+0xb93/0x12d0 [bridge] (0xffffffffc06739b3)\n origin: software\n timestamp: Mon May 13 11:31:53 2024 778214037 nsec\n protocol: 0x88a8\n length: 2\n original length: 2\n drop reason: PKT_TOO_SMALL\n\n[1]\nBUG: KMSAN: uninit-value in br_dev_xmit+0x61d/0x1cb0 net/bridge/br_device.c:65\n br_dev_xmit+0x61d/0x1cb0 net/bridge/br_device.c:65\n __netdev_start_xmit include/linux/netdevice.h:4903 [inline]\n netdev_start_xmit include/linux/netdevice.h:4917 [inline]\n xmit_one net/core/dev.c:3531 [inline]\n dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3547\n __dev_queue_xmit+0x34db/0x5350 net/core/dev.c:4341\n dev_queue_xmit include/linux/netdevice.h:3091 [inline]\n __bpf_tx_skb net/core/filter.c:2136 [inline]\n __bpf_redirect_common net/core/filter.c:2180 [inline]\n __bpf_redirect+0x14a6/0x1620 net/core/filter.c:2187\n ____bpf_clone_redirect net/core/filter.c:2460 [inline]\n bpf_clone_redirect+0x328/0x470 net/core/filter.c:2432\n ___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997\n __bpf_prog_run512+0xb5/0xe0 kernel/bpf/core.c:2238\n bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]\n __bpf_prog_run include/linux/filter.h:657 [inline]\n bpf_prog_run include/linux/filter.h:664 [inline]\n bpf_test_run+0x499/0xc30 net/bpf/test_run.c:425\n bpf_prog_test_run_skb+0x14ea/0x1f20 net/bpf/test_run.c:1058\n bpf_prog_test_run+0x6b7/0xad0 kernel/bpf/syscall.c:4269\n __sys_bpf+0x6aa/0xd90 kernel/bpf/syscall.c:5678\n __do_sys_bpf kernel/bpf/syscall.c:5767 [inline]\n __se_sys_bpf kernel/bpf/syscall.c:5765 [inline]\n __x64_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5765\n x64_sys_call+0x96b/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:322\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f","modified":"2026-04-01T05:16:01.597826Z","published":"2024-06-19T14:15:14Z","upstream":["CVE-2024-38538"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-38538"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.176.3-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-48297.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H"}]}