| 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-2024-56674: virtio_net: correct netdev_tx_reset_queue() invocation point |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| virtio_net: correct netdev_tx_reset_queue() invocation point |
| |
| When virtnet_close is followed by virtnet_open, some TX completions can |
| possibly remain unconsumed, until they are finally processed during the |
| first NAPI poll after the netdev_tx_reset_queue(), resulting in a crash |
| [1]. Commit b96ed2c97c79 ("virtio_net: move netdev_tx_reset_queue() call |
| before RX napi enable") was not sufficient to eliminate all BQL crash |
| cases for virtio-net. |
| |
| This issue can be reproduced with the latest net-next master by running: |
| `while :; do ip l set DEV down; ip l set DEV up; done` under heavy network |
| TX load from inside the machine. |
| |
| netdev_tx_reset_queue() can actually be dropped from virtnet_open path; |
| the device is not stopped in any case. For BQL core part, it's just like |
| traffic nearly ceases to exist for some period. For stall detector added |
| to BQL, even if virtnet_close could somehow lead to some TX completions |
| delayed for long, followed by virtnet_open, we can just take it as stall |
| as mentioned in commit 6025b9135f7a ("net: dqs: add NIC stall detector |
| based on BQL"). Note also that users can still reset stall_max via sysfs. |
| |
| So, drop netdev_tx_reset_queue() from virtnet_enable_queue_pair(). This |
| eliminates the BQL crashes. As a result, netdev_tx_reset_queue() is now |
| explicitly required in freeze/restore path. This patch adds it to |
| immediately after free_unused_bufs(), following the rule of thumb: |
| netdev_tx_reset_queue() should follow any SKB freeing not followed by |
| netdev_tx_completed_queue(). This seems the most consistent and |
| streamlined approach, and now netdev_tx_reset_queue() runs whenever |
| free_unused_bufs() is done. |
| |
| [1]: |
| ------------[ cut here ]------------ |
| kernel BUG at lib/dynamic_queue_limits.c:99! |
| Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI |
| CPU: 7 UID: 0 PID: 1598 Comm: ip Tainted: G N 6.12.0net-next_main+ #2 |
| Tainted: [N]=TEST |
| Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), \ |
| BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 |
| RIP: 0010:dql_completed+0x26b/0x290 |
| Code: b7 c2 49 89 e9 44 89 da 89 c6 4c 89 d7 e8 ed 17 47 00 58 65 ff 0d |
| 4d 27 90 7e 0f 85 fd fe ff ff e8 ea 53 8d ff e9 f3 fe ff ff <0f> 0b 01 |
| d2 44 89 d1 29 d1 ba 00 00 00 00 0f 48 ca e9 28 ff ff ff |
| RSP: 0018:ffffc900002b0d08 EFLAGS: 00010297 |
| RAX: 0000000000000000 RBX: ffff888102398c80 RCX: 0000000080190009 |
| RDX: 0000000000000000 RSI: 000000000000006a RDI: 0000000000000000 |
| RBP: ffff888102398c00 R08: 0000000000000000 R09: 0000000000000000 |
| R10: 00000000000000ca R11: 0000000000015681 R12: 0000000000000001 |
| R13: ffffc900002b0d68 R14: ffff88811115e000 R15: ffff8881107aca40 |
| FS: 00007f41ded69500(0000) GS:ffff888667dc0000(0000) |
| knlGS:0000000000000000 |
| CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| CR2: 0000556ccc2dc1a0 CR3: 0000000104fd8003 CR4: 0000000000772ef0 |
| PKRU: 55555554 |
| Call Trace: |
| <IRQ> |
| ? die+0x32/0x80 |
| ? do_trap+0xd9/0x100 |
| ? dql_completed+0x26b/0x290 |
| ? dql_completed+0x26b/0x290 |
| ? do_error_trap+0x6d/0xb0 |
| ? dql_completed+0x26b/0x290 |
| ? exc_invalid_op+0x4c/0x60 |
| ? dql_completed+0x26b/0x290 |
| ? asm_exc_invalid_op+0x16/0x20 |
| ? dql_completed+0x26b/0x290 |
| __free_old_xmit+0xff/0x170 [virtio_net] |
| free_old_xmit+0x54/0xc0 [virtio_net] |
| virtnet_poll+0xf4/0xe30 [virtio_net] |
| ? __update_load_avg_cfs_rq+0x264/0x2d0 |
| ? update_curr+0x35/0x260 |
| ? reweight_entity+0x1be/0x260 |
| __napi_poll.constprop.0+0x28/0x1c0 |
| net_rx_action+0x329/0x420 |
| ? enqueue_hrtimer+0x35/0x90 |
| ? trace_hardirqs_on+0x1d/0x80 |
| ? kvm_sched_clock_read+0xd/0x20 |
| ? sched_clock+0xc/0x30 |
| ? kvm_sched_clock_read+0xd/0x20 |
| ? sched_clock+0xc/0x30 |
| ? sched_clock_cpu+0xd/0x1a0 |
| handle_softirqs+0x138/0x3e0 |
| do_softirq.part.0+0x89/0xc0 |
| </IRQ> |
| <TASK> |
| __local_bh_enable_ip+0xa7/0xb0 |
| virtnet_open+0xc8/0x310 [virtio_net] |
| __dev_open+0xfa/0x1b0 |
| __dev_change_flags+0x1de/0x250 |
| dev_change_flags+0x22/0x60 |
| do_setlink.isra.0+0x2df/0x10b0 |
| ? rtnetlink_rcv_msg+0x34f/0x3f0 |
| ? netlink_rcv_skb+0x54/0x100 |
| ? netlink_unicast+0x23e/0x390 |
| ? netlink_sendmsg+0x21e/0x490 |
| ? ____sys_sendmsg+0x31b/0x350 |
| ? avc_has_perm_noaudit+0x67/0xf0 |
| ? cred_has_capability.isra.0+0x75/0x110 |
| ? __nla_validate_parse+0x5f/0xee0 |
| ? __pfx___probestub_irq_enable+0x3/0x10 |
| ? __create_object+0x5e/0x90 |
| ? security_capable+0x3b/0x70 |
| rtnl_newlink+0x784/0xaf0 |
| ? avc_has_perm_noaudit+0x67/0xf0 |
| ? cred_has_capability.isra.0+0x75/0x110 |
| ? stack_depot_save_flags+0x24/0x6d0 |
| ? __pfx_rtnl_newlink+0x10/0x10 |
| rtnetlink_rcv_msg+0x34f/0x3f0 |
| ? do_syscall_64+0x6c/0x180 |
| ? entry_SYSCALL_64_after_hwframe+0x76/0x7e |
| ? __pfx_rtnetlink_rcv_msg+0x10/0x10 |
| netlink_rcv_skb+0x54/0x100 |
| netlink_unicast+0x23e/0x390 |
| netlink_sendmsg+0x21e/0x490 |
| ____sys_sendmsg+0x31b/0x350 |
| ? copy_msghdr_from_user+0x6d/0xa0 |
| ___sys_sendmsg+0x86/0xd0 |
| ? __pte_offset_map+0x17/0x160 |
| ? preempt_count_add+0x69/0xa0 |
| ? __call_rcu_common.constprop.0+0x147/0x610 |
| ? preempt_count_add+0x69/0xa0 |
| ? preempt_count_add+0x69/0xa0 |
| ? _raw_spin_trylock+0x13/0x60 |
| ? trace_hardirqs_on+0x1d/0x80 |
| __sys_sendmsg+0x66/0xc0 |
| do_syscall_64+0x6c/0x180 |
| entry_SYSCALL_64_after_hwframe+0x76/0x7e |
| RIP: 0033:0x7f41defe5b34 |
| Code: 15 e1 12 0f 00 f7 d8 64 89 02 b8 ff ff ff ff eb bf 0f 1f 44 00 00 |
| f3 0f 1e fa 80 3d 35 95 0f 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 |
| f0 ff ff 77 4c c3 0f 1f 00 55 48 89 e5 48 83 ec 20 89 55 |
| RSP: 002b:00007ffe5336ecc8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e |
| RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f41defe5b34 |
| RDX: 0000000000000000 RSI: 00007ffe5336ed30 RDI: 0000000000000003 |
| RBP: 00007ffe5336eda0 R08: 0000000000000010 R09: 0000000000000001 |
| R10: 00007ffe5336f6f9 R11: 0000000000000202 R12: 0000000000000003 |
| R13: 0000000067452259 R14: 0000556ccc28b040 R15: 0000000000000000 |
| </TASK> |
| [...] |
| |
| [ pabeni: trimmed possibly troublesome separator ] |
| |
| The Linux kernel CVE team has assigned CVE-2024-56674 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.11 with commit c8bd1f7f3e61fc6c562c806045f3ccd2cc819c01 and fixed in 6.12.6 with commit b4294d4ac61fbb382811a1d64eaf81f446ce2af4 |
| Issue introduced in 6.11 with commit c8bd1f7f3e61fc6c562c806045f3ccd2cc819c01 and fixed in 6.13 with commit 3ddccbefebdbe0c4c72a248676e4d39ac66a8e26 |
| |
| 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-2024-56674 |
| 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: |
| drivers/net/virtio_net.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/b4294d4ac61fbb382811a1d64eaf81f446ce2af4 |
| https://git.kernel.org/stable/c/3ddccbefebdbe0c4c72a248676e4d39ac66a8e26 |
