Описание
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Check for NOT_READY flag state after locking
Currently the check for NOT_READY flag is performed before obtaining the
necessary lock. This opens a possibility for race condition when the flow
is concurrently removed from unready_flows list by the workqueue task,
which causes a double-removal from the list and a crash[0]. Fix the issue
by moving the flag check inside the section protected by
uplink_priv->unready_flows_lock mutex.
[0]:
[44376.389654] general protection fault, probably for non-canonical address 0xdead000000000108: 0000 [#1] SMP
[44376.391665] CPU: 7 PID: 59123 Comm: tc Not tainted 6.4.0-rc4+ #1
[44376.392984] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[44376.395342] RIP: 0010:mlx5e_tc_del_fdb_flow+0xb3/0x340 [mlx5_core]
[44376.396857] Code: 00 48 8b b8 68 ce 02 00 e8 8a 4d 02 00 4c 8d a8 a8 01 00 00 4c 89 ef e8 8b 79 88 e1 48 8b 83 98 06 00 00 48 8b 93 90 06 00 00 <48> 89 42 08 48 89 10 48 b8 00 01 00 00 00 00 ad de 48 89 83 90 06
[44376.399167] RSP: 0018:ffff88812cc97570 EFLAGS: 00010246
[44376.399680] RAX: dead000000000122 RBX: ffff8881088e3800 RCX: ffff8881881bac00
[44376.400337] RDX: dead000000000100 RSI: ffff88812cc97500 RDI: ffff8881242f71b0
[44376.401001] RBP: ffff88811cbb0940 R08: 0000000000000400 R09: 0000000000000001
[44376.401663] R10: 0000000000000001 R11: 0000000000000000 R12: ffff88812c944000
[44376.402342] R13: ffff8881242f71a8 R14: ffff8881222b4000 R15: 0000000000000000
[44376.402999] FS: 00007f0451104800(0000) GS:ffff88852cb80000(0000) knlGS:0000000000000000
[44376.403787] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[44376.404343] CR2: 0000000000489108 CR3: 0000000123a79003 CR4: 0000000000370ea0
[44376.405004] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[44376.405665] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[44376.406339] Call Trace:
[44376.406651]
[44376.406939] ? die_addr+0x33/0x90
[44376.407311] ? exc_general_protection+0x192/0x390
[44376.407795] ? asm_exc_general_protection+0x22/0x30
[44376.408292] ? mlx5e_tc_del_fdb_flow+0xb3/0x340 [mlx5_core]
[44376.408876] __mlx5e_tc_del_fdb_peer_flow+0xbc/0xe0 [mlx5_core]
[44376.409482] mlx5e_tc_del_flow+0x42/0x210 [mlx5_core]
[44376.410055] mlx5e_flow_put+0x25/0x50 [mlx5_core]
[44376.410529] mlx5e_delete_flower+0x24b/0x350 [mlx5_core]
[44376.411043] tc_setup_cb_reoffload+0x22/0x80
[44376.411462] fl_reoffload+0x261/0x2f0 [cls_flower]
[44376.411907] ? mlx5e_rep_indr_setup_ft_cb+0x160/0x160 [mlx5_core]
[44376.412481] ? mlx5e_rep_indr_setup_ft_cb+0x160/0x160 [mlx5_core]
[44376.413044] tcf_block_playback_offloads+0x76/0x170
[44376.413497] tcf_block_unbind+0x7b/0xd0
[44376.413881] tcf_block_setup+0x17d/0x1c0
[44376.414269] tcf_block_offload_cmd.isra.0+0xf1/0x130
[44376.414725] tcf_block_offload_unbind+0x43/0x70
[44376.415153] __tcf_block_put+0x82/0x150
[44376.415532] ingress_destroy+0x22/0x30 [sch_ingress]
[44376.415986] qdisc_destroy+0x3b/0xd0
[44376.416343] qdisc_graft+0x4d0/0x620
[44376.416706] tc_get_qdisc+0x1c9/0x3b0
[44376.417074] rtnetlink_rcv_msg+0x29c/0x390
[44376.419978] ? rep_movs_alternative+0x3a/0xa0
[44376.420399] ? rtnl_calcit.isra.0+0x120/0x120
[44376.420813] netlink_rcv_skb+0x54/0x100
[44376.421192] netlink_unicast+0x1f6/0x2c0
[44376.421573] netlink_sendmsg+0x232/0x4a0
[44376.421980] sock_sendmsg+0x38/0x60
[44376.422328] ____sys_sendmsg+0x1d0/0x1e0
[44376.422709] ? copy_msghdr_from_user+0x6d/0xa0
[44376.423127] ___sys_sendmsg+0x80/0xc0
[44376.423495] ? ___sys_recvmsg+0x8b/0xc0
[44376.423869] __sys_sendmsg+0x51/0x90
[44376.424226] do_syscall_64+0x3d/0x90
[44376.424587] entry_SYSCALL_64_after_hwframe+0x46/0xb0
[44376.425046] RIP: 0033:0x7f045134f887
[44376.425403] Code: 0a 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00
---truncated---
A race condition was found in the Linux kernel Mellanox mlx5 network driver's traffic control offload flow management.
A local user with privileges to configure traffic control flower filters can trigger concurrent flow deletion operations where the NOT_READY flag is checked before acquiring the necessary lock, allowing a workqueue task to concurrently remove the flow from the unready_flows list, which causes double-removal from the linked list and results in list corruption leading to denial of service via kernel crash or potentially memory corruption.
Отчет
The issue arises because of incorrect lock ordering in the flow deletion path. When mlx5e_tc_del_fdb_flow() processes a flow deletion, it first checks the NOT_READY flag to determine if the flow is on the unready_flows list, then acquires the uplink_priv->unready_flows_lock mutex to remove it. However, between the flag check and lock acquisition, a workqueue task can acquire the same lock and remove the flow from the list. When the original thread then acquires the lock and attempts list removal, it performs a double-removal on an entry that is no longer in the list. This corrupts the linked list pointers, causing subsequent list operations to access freed memory containing poison values (0xdead000000000100). The race window is narrow, requiring the workqueue to execute between the flag check and lock acquisition. While this reliably causes kernel crashes when the race occurs, the underlying list corruption represents a memory safety violation that could potentially be leveraged for more sophisticated attacks with careful timing and heap manipulation.
Меры по смягчению последствий
To mitigate this issue, prevent the mlx5_core module from loading. See https://access.redhat.com/solutions/41278 for instructions on blacklisting kernel modules.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Affected | ||
| Red Hat Enterprise Linux 8 | kernel | Fixed | RHSA-2020:1769 | 28.04.2020 |
| Red Hat Enterprise Linux 8 | kernel | Fixed | RHSA-2024:3138 | 22.05.2024 |
| Red Hat Enterprise Linux 8.2 Advanced Update Support | kernel | Fixed | RHSA-2026:2664 | 12.02.2026 |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | kernel | Fixed | RHSA-2026:3360 | 25.02.2026 |
Показывать по
Дополнительная информация
Статус:
7 High
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Check for NOT_READY flag state after locking Currently the check for NOT_READY flag is performed before obtaining the necessary lock. This opens a possibility for race condition when the flow is concurrently removed from unready_flows list by the workqueue task, which causes a double-removal from the list and a crash[0]. Fix the issue by moving the flag check inside the section protected by uplink_priv->unready_flows_lock mutex. [0]: [44376.389654] general protection fault, probably for non-canonical address 0xdead000000000108: 0000 [#1] SMP [44376.391665] CPU: 7 PID: 59123 Comm: tc Not tainted 6.4.0-rc4+ #1 [44376.392984] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [44376.395342] RIP: 0010:mlx5e_tc_del_fdb_flow+0xb3/0x340 [mlx5_core] [44376.396857] Code: 00 48 8b b8 68 ce 02 00 e8 8a 4d 02 00 4c 8d a8 a8 01 00 00 4c 89 ef e8 8b 79 88 e1...
In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Check for NOT_READY flag state after locking Currently the check for NOT_READY flag is performed before obtaining the necessary lock. This opens a possibility for race condition when the flow is concurrently removed from unready_flows list by the workqueue task, which causes a double-removal from the list and a crash[0]. Fix the issue by moving the flag check inside the section protected by uplink_priv->unready_flows_lock mutex. [0]: [44376.389654] general protection fault, probably for non-canonical address 0xdead000000000108: 0000 [#1] SMP [44376.391665] CPU: 7 PID: 59123 Comm: tc Not tainted 6.4.0-rc4+ #1 [44376.392984] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [44376.395342] RIP: 0010:mlx5e_tc_del_fdb_flow+0xb3/0x340 [mlx5_core] [44376.396857] Code: 00 48 8b b8 68 ce 02 00 e8 8a 4d 02 00 4c 8d a8 a8 01 00 00 4c 89 ef e8 8b 79 88 e1
In the Linux kernel, the following vulnerability has been resolved: n ...
In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Check for NOT_READY flag state after locking Currently the check for NOT_READY flag is performed before obtaining the necessary lock. This opens a possibility for race condition when the flow is concurrently removed from unready_flows list by the workqueue task, which causes a double-removal from the list and a crash[0]. Fix the issue by moving the flag check inside the section protected by uplink_priv->unready_flows_lock mutex. [0]: [44376.389654] general protection fault, probably for non-canonical address 0xdead000000000108: 0000 [#1] SMP [44376.391665] CPU: 7 PID: 59123 Comm: tc Not tainted 6.4.0-rc4+ #1 [44376.392984] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [44376.395342] RIP: 0010:mlx5e_tc_del_fdb_flow+0xb3/0x340 [mlx5_core] [44376.396857] Code: 00 48 8b b8 68 ce 02 00 e8 8a 4d 02 00 4c 8d a8 a8 01 00 00 4c 89 ef e8 8b 79 88...
7 High
CVSS3