CVE-2023-53831 in Linux
Zusammenfassung
von VulDB • 21.05.2026
Implied question: What is causing the kernel crash/panic shown in the call trace?
Answer: The call trace shows a crash in the IPv6 output path (`ip6_finish_output2`) triggered from an ipvlan device (`ipvlan_xmit_mode_l3` → `ipvlan_start_xmit`). The key register values are:
- CR3: 000000014ee5b000 (page table base) - DR6: 00000000fffe0ff0 - DR7: 0000000000000400
DR6 = 0xfffe0ff0 and DR7 = 0x400 indicate that a debug exception occurred due to a breakpoint (DR7 bit 0 set) or single-step, but more importantly, the pattern 0xfffe0ff0 in DR6 typically means that one or more debug registers triggered. However, in crash dumps this often correlates with a NULL pointer dereference or invalid memory access during packet processing.
Given the context: - The crash happens in `ip6_finish_output2`, which is part of IPv6 packet transmission. - The packet is being sent through an ipvlan device in L3 mode. - The call trace ends in softirq context (`net_tx_action` → `__do_softirq`), which is typical for network TX completion.
Most likely cause: A NULL pointer dereference or invalid memory access in the IPv6 output path, possibly due to: 1. A bug in the ipvlan driver when handling IPv6 packets in L3 mode. 2. Corrupted or invalid network device state. 3. A race condition or use-after-free in the network stack.
Recommended actions: 1. Check kernel logs (`dmesg`) for the exact oops message (e.g., "BUG: unable to handle kernel NULL pointer dereference at ..."). 2. Verify the kernel version and check for known bugs in ipvlan or IPv6 output path. 3. Update to a newer kernel if a fix is available. 4. If possible, reproduce with a minimal test case and report to the kernel maintainers. 5. As a workaround, consider using ipvlan in L2 mode or another virtual interface type if L3 mode is not strictly required.
Note: Without the full oops message (including the faulting address and register dump), this is an educated guess based on the call trace and debug registers.
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