{"id":"DEBIAN-CVE-2022-50253","details":"In the Linux kernel, the following vulnerability has been resolved:  bpf: make sure skb-\u003elen != 0 when redirecting to a tunneling device  syzkaller managed to trigger another case where skb-\u003elen == 0 when we enter __dev_queue_xmit:  WARNING: CPU: 0 PID: 2470 at include/linux/skbuff.h:2576 skb_assert_len include/linux/skbuff.h:2576 [inline] WARNING: CPU: 0 PID: 2470 at include/linux/skbuff.h:2576 __dev_queue_xmit+0x2069/0x35e0 net/core/dev.c:4295  Call Trace:  dev_queue_xmit+0x17/0x20 net/core/dev.c:4406  __bpf_tx_skb net/core/filter.c:2115 [inline]  __bpf_redirect_no_mac net/core/filter.c:2140 [inline]  __bpf_redirect+0x5fb/0xda0 net/core/filter.c:2163  ____bpf_clone_redirect net/core/filter.c:2447 [inline]  bpf_clone_redirect+0x247/0x390 net/core/filter.c:2419  bpf_prog_48159a89cb4a9a16+0x59/0x5e  bpf_dispatcher_nop_func include/linux/bpf.h:897 [inline]  __bpf_prog_run include/linux/filter.h:596 [inline]  bpf_prog_run include/linux/filter.h:603 [inline]  bpf_test_run+0x46c/0x890 net/bpf/test_run.c:402  bpf_prog_test_run_skb+0xbdc/0x14c0 net/bpf/test_run.c:1170  bpf_prog_test_run+0x345/0x3c0 kernel/bpf/syscall.c:3648  __sys_bpf+0x43a/0x6c0 kernel/bpf/syscall.c:5005  __do_sys_bpf kernel/bpf/syscall.c:5091 [inline]  __se_sys_bpf kernel/bpf/syscall.c:5089 [inline]  __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5089  do_syscall_64+0x54/0x70 arch/x86/entry/common.c:48  entry_SYSCALL_64_after_hwframe+0x61/0xc6  The reproducer doesn't really reproduce outside of syzkaller environment, so I'm taking a guess here. It looks like we do generate correct ETH_HLEN-sized packet, but we redirect the packet to the tunneling device. Before we do so, we __skb_pull l2 header and arrive again at skb-\u003elen == 0. Doesn't seem like we can do anything better than having an explicit check after __skb_pull?","modified":"2026-09-01T20:04:58.054105510Z","published":"2025-09-15T14:15:36.007Z","upstream":["CVE-2022-50253"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2022-50253"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.4-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50253.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.4-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50253.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.4-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50253.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}