net/sched: act_skbmod: prevent kernel-infoleak

Summary

CVECVE-2024-35893
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2024-05-19 09:15:10 UTC
Updated2026-05-12 12:16:39 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: net/sched: act_skbmod: prevent kernel-infoleak syzbot found that tcf_skbmod_dump() was copying four bytes from kernel stack to user space [1]. The issue here is that 'struct tc_skbmod' has a four bytes hole. We need to clear the structure before filling fields. [1] BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline] BUG: KMSAN: kernel-infoleak in copy_to_user_iter lib/iov_iter.c:24 [inline] BUG: KMSAN: kernel-infoleak in iterate_ubuf include/linux/iov_iter.h:29 [inline] BUG: KMSAN: kernel-infoleak in iterate_and_advance2 include/linux/iov_iter.h:245 [inline] BUG: KMSAN: kernel-infoleak in iterate_and_advance include/linux/iov_iter.h:271 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x366/0x2520 lib/iov_iter.c:185 instrument_copy_to_user include/linux/instrumented.h:114 [inline] copy_to_user_iter lib/iov_iter.c:24 [inline] iterate_ubuf include/linux/iov_iter.h:29 [inline] iterate_and_advance2 include/linux/iov_iter.h:245 [inline] iterate_and_advance include/linux/iov_iter.h:271 [inline] _copy_to_iter+0x366/0x2520 lib/iov_iter.c:185 copy_to_iter include/linux/uio.h:196 [inline] simple_copy_to_iter net/core/datagram.c:532 [inline] __skb_datagram_iter+0x185/0x1000 net/core/datagram.c:420 skb_copy_datagram_iter+0x5c/0x200 net/core/datagram.c:546 skb_copy_datagram_msg include/linux/skbuff.h:4050 [inline] netlink_recvmsg+0x432/0x1610 net/netlink/af_netlink.c:1962 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg+0x2c4/0x340 net/socket.c:1068 __sys_recvfrom+0x35a/0x5f0 net/socket.c:2242 __do_sys_recvfrom net/socket.c:2260 [inline] __se_sys_recvfrom net/socket.c:2256 [inline] __x64_sys_recvfrom+0x126/0x1d0 net/socket.c:2256 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Uninit was stored to memory at: pskb_expand_head+0x30f/0x19d0 net/core/skbuff.c:2253 netlink_trim+0x2c2/0x330 net/netlink/af_netlink.c:1317 netlink_unicast+0x9f/0x1260 net/netlink/af_netlink.c:1351 nlmsg_unicast include/net/netlink.h:1144 [inline] nlmsg_notify+0x21d/0x2f0 net/netlink/af_netlink.c:2610 rtnetlink_send+0x73/0x90 net/core/rtnetlink.c:741 rtnetlink_maybe_send include/linux/rtnetlink.h:17 [inline] tcf_add_notify net/sched/act_api.c:2048 [inline] tcf_action_add net/sched/act_api.c:2071 [inline] tc_ctl_action+0x146e/0x19d0 net/sched/act_api.c:2119 rtnetlink_rcv_msg+0x1737/0x1900 net/core/rtnetlink.c:6595 netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2559 rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6613 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0xf4c/0x1260 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x10df/0x11f0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x30f/0x380 net/socket.c:745 ____sys_sendmsg+0x877/0xb60 net/socket.c:2584 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638 __sys_sendmsg net/socket.c:2667 [inline] __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2674 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Uninit was stored to memory at: __nla_put lib/nlattr.c:1041 [inline] nla_put+0x1c6/0x230 lib/nlattr.c:1099 tcf_skbmod_dump+0x23f/0xc20 net/sched/act_skbmod.c:256 tcf_action_dump_old net/sched/act_api.c:1191 [inline] tcf_action_dump_1+0x85e/0x970 net/sched/act_api.c:1227 tcf_action_dump+0x1fd/0x460 net/sched/act_api.c:1251 tca_get_fill+0x519/0x7a0 net/sched/act_api.c:1628 tcf_add_notify_msg net/sched/act_api.c:2023 [inline] tcf_add_notify net/sched/act_api.c:2042 [inline] tcf_action_add net/sched/act_api.c:2071 [inline] tc_ctl_action+0x1365/0x19d0 net/sched/act_api.c:2119 rtnetlink_rcv_msg+0x1737/0x1900 net/core/rtnetlink.c:6595 netlink_rcv_skb+0x375/0x650 net/netlink/af_netli ---truncated---

Risk And Classification

Primary CVSS: v3.1 5.5 MEDIUM from [email protected]

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Problem Types: CWE-908

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 86da71b57383d40993cb90baafb3735cffe5d800 f190a4aa03cbd518bd9c62a66e1233984f5fd2ec git Not specified
CNA Linux Linux affected 86da71b57383d40993cb90baafb3735cffe5d800 f356eb2fb567e0931143ac1769ac802d3b3e2077 git Not specified
CNA Linux Linux affected 86da71b57383d40993cb90baafb3735cffe5d800 5e45dc4408857305f4685abfd7a528a1e58b51b5 git Not specified
CNA Linux Linux affected 86da71b57383d40993cb90baafb3735cffe5d800 a097fc199ab5f4b5392c5144034c0d2148b55a14 git Not specified
CNA Linux Linux affected 86da71b57383d40993cb90baafb3735cffe5d800 55d3fe7b2b7bc354e7cbc1f7b8f98a29ccd5a366 git Not specified
CNA Linux Linux affected 86da71b57383d40993cb90baafb3735cffe5d800 729ad2ac2a2cdc9f4a4bdfd40bfd276e6bc33924 git Not specified
CNA Linux Linux affected 86da71b57383d40993cb90baafb3735cffe5d800 7bb2c7103d8c13b06a57bf997b8cdbe93cd7283c git Not specified
CNA Linux Linux affected 86da71b57383d40993cb90baafb3735cffe5d800 d313eb8b77557a6d5855f42d2234bd592c7b50dd git Not specified
CNA Linux Linux affected 4.9 Not specified
CNA Linux Linux unaffected 4.9 semver Not specified
CNA Linux Linux unaffected 4.19.312 4.19.* semver Not specified
CNA Linux Linux unaffected 5.4.274 5.4.* semver Not specified
CNA Linux Linux unaffected 5.10.215 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.154 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.85 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.26 6.6.* semver Not specified
CNA Linux Linux unaffected 6.8.5 6.8.* semver Not specified
CNA Linux Linux unaffected 6.9 * original_commit_for_fix Not specified
ADP Siemens SIMATIC S7-1500 TM MFP - GNU/Linux Subsystem affected * custom Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/d313eb8b77557a6d5855f42d2234bd592c7b50dd af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
lists.debian.org/debian-lts-announce/2024/06/msg00017.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org Third Party Advisory
git.kernel.org/stable/c/f190a4aa03cbd518bd9c62a66e1233984f5fd2ec af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
cert-portal.siemens.com/productcert/html/ssa-265688.html 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e cert-portal.siemens.com
git.kernel.org/stable/c/55d3fe7b2b7bc354e7cbc1f7b8f98a29ccd5a366 af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
git.kernel.org/stable/c/f356eb2fb567e0931143ac1769ac802d3b3e2077 af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
git.kernel.org/stable/c/729ad2ac2a2cdc9f4a4bdfd40bfd276e6bc33924 af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
git.kernel.org/stable/c/7bb2c7103d8c13b06a57bf997b8cdbe93cd7283c af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
git.kernel.org/stable/c/5e45dc4408857305f4685abfd7a528a1e58b51b5 af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
lists.debian.org/debian-lts-announce/2024/06/msg00020.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org Third Party Advisory
git.kernel.org/stable/c/a097fc199ab5f4b5392c5144034c0d2148b55a14 af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
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