| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-35893: net/sched: act_skbmod: prevent kernel-infoleak |
| |
| Description |
| =========== |
| |
| In 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_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 |
| |
| Local variable opt created at: |
| tcf_skbmod_dump+0x9d/0xc20 net/sched/act_skbmod.c:244 |
| tcf_action_dump_old net/sched/act_api.c:1191 [inline] |
| tcf_action_dump_1+0x85e/0x970 net/sched/act_api.c:1227 |
| |
| Bytes 188-191 of 248 are uninitialized |
| Memory access of size 248 starts at ffff888117697680 |
| Data copied to user address 00007ffe56d855f0 |
| |
| The Linux kernel CVE team has assigned CVE-2024-35893 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.9 with commit 86da71b57383d40993cb90baafb3735cffe5d800 and fixed in 4.19.312 with commit f190a4aa03cbd518bd9c62a66e1233984f5fd2ec |
| Issue introduced in 4.9 with commit 86da71b57383d40993cb90baafb3735cffe5d800 and fixed in 5.4.274 with commit f356eb2fb567e0931143ac1769ac802d3b3e2077 |
| Issue introduced in 4.9 with commit 86da71b57383d40993cb90baafb3735cffe5d800 and fixed in 5.10.215 with commit 5e45dc4408857305f4685abfd7a528a1e58b51b5 |
| Issue introduced in 4.9 with commit 86da71b57383d40993cb90baafb3735cffe5d800 and fixed in 5.15.154 with commit a097fc199ab5f4b5392c5144034c0d2148b55a14 |
| Issue introduced in 4.9 with commit 86da71b57383d40993cb90baafb3735cffe5d800 and fixed in 6.1.85 with commit 55d3fe7b2b7bc354e7cbc1f7b8f98a29ccd5a366 |
| Issue introduced in 4.9 with commit 86da71b57383d40993cb90baafb3735cffe5d800 and fixed in 6.6.26 with commit 729ad2ac2a2cdc9f4a4bdfd40bfd276e6bc33924 |
| Issue introduced in 4.9 with commit 86da71b57383d40993cb90baafb3735cffe5d800 and fixed in 6.8.5 with commit 7bb2c7103d8c13b06a57bf997b8cdbe93cd7283c |
| Issue introduced in 4.9 with commit 86da71b57383d40993cb90baafb3735cffe5d800 and fixed in 6.9 with commit d313eb8b77557a6d5855f42d2234bd592c7b50dd |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-35893 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| net/sched/act_skbmod.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/f190a4aa03cbd518bd9c62a66e1233984f5fd2ec |
| https://git.kernel.org/stable/c/f356eb2fb567e0931143ac1769ac802d3b3e2077 |
| https://git.kernel.org/stable/c/5e45dc4408857305f4685abfd7a528a1e58b51b5 |
| https://git.kernel.org/stable/c/a097fc199ab5f4b5392c5144034c0d2148b55a14 |
| https://git.kernel.org/stable/c/55d3fe7b2b7bc354e7cbc1f7b8f98a29ccd5a366 |
| https://git.kernel.org/stable/c/729ad2ac2a2cdc9f4a4bdfd40bfd276e6bc33924 |
| https://git.kernel.org/stable/c/7bb2c7103d8c13b06a57bf997b8cdbe93cd7283c |
| https://git.kernel.org/stable/c/d313eb8b77557a6d5855f42d2234bd592c7b50dd |
