CVE-2025-38439 bnxt_en: Set DMA unmap len correctly for XDP_REDIRECT
A bug in the bnxt_en driver causes incorrect DMA unmap lengths during XDP redirects, triggering kernel warnings and potential instability on systems with IOMMU enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-38439?
CVE-2025-38439 is a critical vulnerability in Debian Debian Linux, published on 25 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
bnxt_en: Set DMA unmap len correctly for XDP_REDIRECT
When transmitting an XDP_REDIRECT packet, call dma_unmap_len_set() with the proper length instead of 0. This bug triggers this warning on a system with IOMMU enabled:
WARNING: CPU: 36 PID: 0 at drivers/iommu/dma-iommu.c:842 __iommu_dma_unmap+0x159/0x170 RIP: 0010:__iommu_dma_unmap+0x159/0x170 Code: a8 00 00 00 00 48 c7 45 b0 00 00 00 00 48 c7 45 c8 00 00 00 00 48 c7 45 a0 ff ff ff ff 4c 89 45 b8 4c 89 45 c0 e9 77 ff ff ff <0f> 0b e9 60 ff ff ff e8 8b bf 6a 00 66 66 2e 0f 1f 84 00 00 00 00 RSP: 0018:ff22d31181150c88 EFLAGS: 00010206 RAX: 0000000000002000 RBX: 00000000e13a0000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ff22d31181150cf0 R08: ff22d31181150ca8 R09: 0000000000000000 R10: 0000000000000000 R11: ff22d311d36c9d80 R12: 0000000000001000 R13: ff13544d10645010 R14: ff22d31181150c90 R15: ff13544d0b2bac00 FS: 0000000000000000(0000) GS:ff13550908a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005be909dacff8 CR3: 0008000173408003 CR4: 0000000000f71ef0 PKRU: 55555554 Call Trace: <IRQ> ? show_regs+0x6d/0x80 ? __warn+0x89/0x160 ? __iommu_dma_unmap+0x159/0x170 ? report_bug+0x17e/0x1b0 ? handle_bug+0x46/0x90 ? exc_invalid_op+0x18/0x80 ? asm_exc_invalid_op+0x1b/0x20 ? __iommu_dma_unmap+0x159/0x170 ? __iommu_dma_unmap+0xb3/0x170 iommu_dma_unmap_page+0x4f/0x100 dma_unmap_page_attrs+0x52/0x220 ? srso_alias_return_thunk+0x5/0xfbef5 ? xdp_return_frame+0x2e/0xd0 bnxt_tx_int_xdp+0xdf/0x440 [bnxt_en] __bnxt_poll_work_done+0x81/0x1e0 [bnxt_en] bnxt_poll+0xd3/0x1e0 [bnxt_en]
Which versions are affected by CVE-2025-38439?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-38439?
Apply the vendor's patch.
Is CVE-2025-38439 being exploited?
There is no known exploitation of CVE-2025-38439 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as AZL-65705, AZL-72917, BELL-CVE-2025-38439, DEBIAN-CVE-2025-38439, GHSA-55p2-7r59-rr9c, ROOT-OS-DEBIAN-11-CVE-2025-38439 and 4 more.