ghsa-4c77-8jrg-w382
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Fix race between DIM disable and net_dim()
There's a race between disabling DIM and NAPI callbacks using the dim pointer on the RQ or SQ.
If NAPI checks the DIM state bit and sees it still set, it assumes
rq->dim or sq->dim is valid. But if DIM gets disabled right after
that check, the pointer might already be set to NULL, leading to a NULL
pointer dereference in net_dim().
Fix this by calling synchronize_net() before freeing the DIM context.
This ensures all in-progress NAPI callbacks are finished before the
pointer is cleared.
Kernel log:
BUG: kernel NULL pointer dereference, address: 0000000000000000 ... RIP: 0010:net_dim+0x23/0x190 ... Call Trace: ? __die+0x20/0x60 ? page_fault_oops+0x150/0x3e0 ? common_interrupt+0xf/0xa0 ? sysvec_call_function_single+0xb/0x90 ? exc_page_fault+0x74/0x130 ? asm_exc_page_fault+0x22/0x30 ? net_dim+0x23/0x190 ? mlx5e_poll_ico_cq+0x41/0x6f0 [mlx5_core] ? sysvec_apic_timer_interrupt+0xb/0x90 mlx5e_handle_rx_dim+0x92/0xd0 [mlx5_core] mlx5e_napi_poll+0x2cd/0xac0 [mlx5_core] ? mlx5e_poll_ico_cq+0xe5/0x6f0 [mlx5_core] busy_poll_stop+0xa2/0x200 ? mlx5e_napi_poll+0x1d9/0xac0 [mlx5_core] ? mlx5e_trigger_irq+0x130/0x130 [mlx5_core] __napi_busy_loop+0x345/0x3b0 ? sysvec_call_function_single+0xb/0x90 ? asm_sysvec_call_function_single+0x16/0x20 ? sysvec_apic_timer_interrupt+0xb/0x90 ? pcpu_free_area+0x1e4/0x2e0 napi_busy_loop+0x11/0x20 xsk_recvmsg+0x10c/0x130 sock_recvmsg+0x44/0x70 __sys_recvfrom+0xbc/0x130 ? __schedule+0x398/0x890 __x64_sys_recvfrom+0x20/0x30 do_syscall_64+0x4c/0x100 entry_SYSCALL_64_after_hwframe+0x4b/0x53 ... ---[ end trace 0000000000000000 ]--- ... ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---
{
"affected": [],
"aliases": [
"CVE-2025-38440"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-07-25T16:15:29Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix race between DIM disable and net_dim()\n\nThere\u0027s a race between disabling DIM and NAPI callbacks using the dim\npointer on the RQ or SQ.\n\nIf NAPI checks the DIM state bit and sees it still set, it assumes\n`rq-\u003edim` or `sq-\u003edim` is valid. But if DIM gets disabled right after\nthat check, the pointer might already be set to NULL, leading to a NULL\npointer dereference in net_dim().\n\nFix this by calling `synchronize_net()` before freeing the DIM context.\nThis ensures all in-progress NAPI callbacks are finished before the\npointer is cleared.\n\nKernel log:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000000\n...\nRIP: 0010:net_dim+0x23/0x190\n...\nCall Trace:\n \u003cTASK\u003e\n ? __die+0x20/0x60\n ? page_fault_oops+0x150/0x3e0\n ? common_interrupt+0xf/0xa0\n ? sysvec_call_function_single+0xb/0x90\n ? exc_page_fault+0x74/0x130\n ? asm_exc_page_fault+0x22/0x30\n ? net_dim+0x23/0x190\n ? mlx5e_poll_ico_cq+0x41/0x6f0 [mlx5_core]\n ? sysvec_apic_timer_interrupt+0xb/0x90\n mlx5e_handle_rx_dim+0x92/0xd0 [mlx5_core]\n mlx5e_napi_poll+0x2cd/0xac0 [mlx5_core]\n ? mlx5e_poll_ico_cq+0xe5/0x6f0 [mlx5_core]\n busy_poll_stop+0xa2/0x200\n ? mlx5e_napi_poll+0x1d9/0xac0 [mlx5_core]\n ? mlx5e_trigger_irq+0x130/0x130 [mlx5_core]\n __napi_busy_loop+0x345/0x3b0\n ? sysvec_call_function_single+0xb/0x90\n ? asm_sysvec_call_function_single+0x16/0x20\n ? sysvec_apic_timer_interrupt+0xb/0x90\n ? pcpu_free_area+0x1e4/0x2e0\n napi_busy_loop+0x11/0x20\n xsk_recvmsg+0x10c/0x130\n sock_recvmsg+0x44/0x70\n __sys_recvfrom+0xbc/0x130\n ? __schedule+0x398/0x890\n __x64_sys_recvfrom+0x20/0x30\n do_syscall_64+0x4c/0x100\n entry_SYSCALL_64_after_hwframe+0x4b/0x53\n...\n---[ end trace 0000000000000000 ]---\n...\n---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---",
"id": "GHSA-4c77-8jrg-w382",
"modified": "2025-07-25T18:30:39Z",
"published": "2025-07-25T18:30:39Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-38440"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2bc6fb90486e42dd80e660ef7a40c02b2516c6d6"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7581afc051542e11ccf3ade68acd01b7fb1a3cde"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/eb41a264a3a576dc040ee37c3d9d6b7e2d9be968"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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