{"id":"CVE-2024-35893","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_skbmod: prevent kernel-infoleak\n\nsyzbot found that tcf_skbmod_dump() was copying four bytes\nfrom kernel stack to user space [1].\n\nThe issue here is that …","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_skbmod: prevent kernel-infoleak\n\nsyzbot found that tcf_skbmod_dump() was copying four bytes\nfrom kernel stack to user space [1].\n\nThe issue here is that …","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-908"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 4.9, < 4.19.312","linux_kernel >= 4.20, < 5.4.274","linux_kernel >= 5.5, < 5.10.215","linux_kernel >= 5.11, < 5.15.154","linux_kernel >= 5.16, < 6.1.85","linux_kernel >= 6.2, < 6.6.26","linux_kernel >= 6.7, < 6.8.5","linux_kernel = 6.9","debian_linux = 10.0"],"patched":["linux_kernel 6.8.5"],"published":"2024-05-19","updated":"2026-10-15","sourceUpdated":"2026-10-15T01:17:50.420","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2024-35893","references":[{"url":"https://git.kernel.org/stable/c/55d3fe7b2b7bc354e7cbc1f7b8f98a29ccd5a366","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5e45dc4408857305f4685abfd7a528a1e58b51b5","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/729ad2ac2a2cdc9f4a4bdfd40bfd276e6bc33924","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7bb2c7103d8c13b06a57bf997b8cdbe93cd7283c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a097fc199ab5f4b5392c5144034c0d2148b55a14","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d313eb8b77557a6d5855f42d2234bd592c7b50dd","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f190a4aa03cbd518bd9c62a66e1233984f5fd2ec","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f356eb2fb567e0931143ac1769ac802d3b3e2077","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/55d3fe7b2b7bc354e7cbc1f7b8f98a29ccd5a366","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/5e45dc4408857305f4685abfd7a528a1e58b51b5","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/729ad2ac2a2cdc9f4a4bdfd40bfd276e6bc33924","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/7bb2c7103d8c13b06a57bf997b8cdbe93cd7283c","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/a097fc199ab5f4b5392c5144034c0d2148b55a14","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/d313eb8b77557a6d5855f42d2234bd592c7b50dd","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/f190a4aa03cbd518bd9c62a66e1233984f5fd2ec","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/f356eb2fb567e0931143ac1769ac802d3b3e2077","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-265688.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00234,"epssPercentile":0.14283,"ingestedAt":"2026-10-15T03:30:12.684Z","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2024-05-23T19:31:02.298124Z"},"slug":"CVE-2024-35893","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_skbmod: prevent kernel-infoleak\n\nsyzbot found that tcf_skbmod_dump() was copying four bytes\nfrom kernel stack to user space [1].\n\nThe issue here is that 'struct tc_skbmod' has a four bytes hole.\n\nWe need to clear the structure before filling fields.\n\n[1]\nBUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]\n BUG: KMSAN: kernel-infoleak in copy_to_user_iter lib/iov_iter.c:24 [inline]\n BUG: KMSAN: kernel-infoleak in iterate_ubuf include/linux/iov_iter.h:29 [inline]\n BUG: KMSAN: kernel-infoleak in iterate_and_advance2 include/linux/iov_iter.h:245 [inline]\n BUG: KMSAN: kernel-infoleak in iterate_and_advance include/linux/iov_iter.h:271 [inline]\n BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x366/0x2520 lib/iov_iter.c:185\n  instrument_copy_to_user include/linux/instrumented.h:114 [inline]\n  copy_to_user_iter lib/iov_iter.c:24 [inline]\n  iterate_ubuf include/linux/iov_iter.h:29 [inline]\n  iterate_and_advance2 include/linux/iov_iter.h:245 [inline]\n  iterate_and_advance include/linux/iov_iter.h:271 [inline]\n  _copy_to_iter+0x366/0x2520 lib/iov_iter.c:185\n  copy_to_iter include/linux/uio.h:196 [inline]\n  simple_copy_to_iter net/core/datagram.c:532 [inline]\n  __skb_datagram_iter+0x185/0x1000 net/core/datagram.c:420\n  skb_copy_datagram_iter+0x5c/0x200 net/core/datagram.c:546\n  skb_copy_datagram_msg include/linux/skbuff.h:4050 [inline]\n  netlink_recvmsg+0x432/0x1610 net/netlink/af_netlink.c:1962\n  sock_recvmsg_nosec net/socket.c:1046 [inline]\n  sock_recvmsg+0x2c4/0x340 net/socket.c:1068\n  __sys_recvfrom+0x35a/0x5f0 net/socket.c:2242\n  __do_sys_recvfrom net/socket.c:2260 [inline]\n  __se_sys_recvfrom net/socket.c:2256 [inline]\n  __x64_sys_recvfrom+0x126/0x1d0 net/socket.c:2256\n do_syscall_64+0xd5/0x1f0\n entry_SYSCALL_64_after_hwframe+0x6d/0x75\n\nUninit was stored to memory at:\n  pskb_expand_head+0x30f/0x19d0 net/core/skbuff.c:2253\n  netlink_trim+0x2c2/0x330 net/netlink/af_netlink.c:1317\n  netlink_unicast+0x9f/0x1260 net/netlink/af_netlink.c:1351\n  nlmsg_unicast include/net/netlink.h:1144 [inline]\n  nlmsg_notify+0x21d/0x2f0 net/netlink/af_netlink.c:2610\n  rtnetlink_send+0x73/0x90 net/core/rtnetlink.c:741\n  rtnetlink_maybe_send include/linux/rtnetlink.h:17 [inline]\n  tcf_add_notify net/sched/act_api.c:2048 [inline]\n  tcf_action_add net/sched/act_api.c:2071 [inline]\n  tc_ctl_action+0x146e/0x19d0 net/sched/act_api.c:2119\n  rtnetlink_rcv_msg+0x1737/0x1900 net/core/rtnetlink.c:6595\n  netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2559\n  rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6613\n  netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]\n  netlink_unicast+0xf4c/0x1260 net/netlink/af_netlink.c:1361\n  netlink_sendmsg+0x10df/0x11f0 net/netlink/af_netlink.c:1905\n  sock_sendmsg_nosec net/socket.c:730 [inline]\n  __sock_sendmsg+0x30f/0x380 net/socket.c:745\n  ____sys_sendmsg+0x877/0xb60 net/socket.c:2584\n  ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638\n  __sys_sendmsg net/socket.c:2667 [inline]\n  __do_sys_sendmsg net/socket.c:2676 [inline]\n  __se_sys_sendmsg net/socket.c:2674 [inline]\n  __x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2674\n do_syscall_64+0xd5/0x1f0\n entry_SYSCALL_64_after_hwframe+0x6d/0x75\n\nUninit was stored to memory at:\n  __nla_put lib/nlattr.c:1041 [inline]\n  nla_put+0x1c6/0x230 lib/nlattr.c:1099\n  tcf_skbmod_dump+0x23f/0xc20 net/sched/act_skbmod.c:256\n  tcf_action_dump_old net/sched/act_api.c:1191 [inline]\n  tcf_action_dump_1+0x85e/0x970 net/sched/act_api.c:1227\n  tcf_action_dump+0x1fd/0x460 net/sched/act_api.c:1251\n  tca_get_fill+0x519/0x7a0 net/sched/act_api.c:1628\n  tcf_add_notify_msg net/sched/act_api.c:2023 [inline]\n  tcf_add_notify net/sched/act_api.c:2042 [inline]\n  tcf_action_add net/sched/act_api.c:2071 [inline]\n  tc_ctl_action+0x1365/0x19d0 net/sched/act_api.c:2119\n  rtnetlink_rcv_msg+0x1737/0x1900 net/core/rtnetlink.c:6595\n  netlink_rcv_skb+0x375/0x650 net/netlink/af_netli\n---truncated---\n\n## Affected\n\n- `linux_kernel >= 4.9, < 4.19.312`\n- `linux_kernel >= 4.20, < 5.4.274`\n- `linux_kernel >= 5.5, < 5.10.215`\n- `linux_kernel >= 5.11, < 5.15.154`\n- `linux_kernel >= 5.16, < 6.1.85`\n- `linux_kernel >= 6.2, < 6.6.26`\n- `linux_kernel >= 6.7, < 6.8.5`\n- `linux_kernel = 6.9`\n- `debian_linux = 10.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.8.5`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}