CVE-2025-68322: parisc: Avoid crash due to unaligned access in unwinder
In the Linux kernel, the following vulnerability has been resolved:
parisc: Avoid crash due to unaligned access in unwinder
Guenter Roeck reported this kernel crash on his emulated B160L machine:
Starting network: udhcpc: started, v1.36.1 Backtrace: [<104320d4>] unwindonce+0x1c/0x5c [<10434a00>] walkstackframe.isra.0+0x74/0xb8 [<10434a6c>] archstackwalk+0x28/0x38 [<104e5efc>] stacktracesave+0x48/0x5c [<105d1bdc>] settrackprepare+0x44/0x6c [<105d9c80>] slaballoc+0xfc4/0x1024 [<105d9d38>] slaballoc.isra.0+0x58/0x90 [<105dc80c>] kmemcacheallocnoprof+0x2ac/0x4a0 [<105b8e54>] anonvmaprepare+0x60/0x280 [<105a823c>] vmfanonprepare+0x68/0x94 [<105a8b34>] dowppage+0x8cc/0xf10 [<105aad88>] handlemmfault+0x6c0/0xf08 [<10425568>] dopagefault+0x110/0x440 [<10427938>] handleinterruption+0x184/0x748 [<11178398>] schedule+0x4c/0x190 BUG: spinlock recursion on CPU#0, ifconfig/2420 lock: terminatelock.2+0x0/0x1c, .magic: dead4ead, .owner: ifconfig/2420, .ownercpu: 0
While creating the stack trace, the unwinder uses the stack pointer to guess the previous frame to read the previous stack pointer from memory. The crash happens, because the unwinder tries to read from unaligned memory and as such triggers the unalignment trap handler which then leads to the spinlock recursion and finally to a deadlock.
Fix it by checking the alignment before accessing the memory.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
In the parisc stack unwinder, check the alignment of the memory address before accessing it to avoid unaligned reads and the resulting spinlock recursion/deadlock.
Event History
Frequently Asked Questions
What is the severity of CVE-2025-68322?
CVE-2025-68322 has a medium severity level due to its potential to cause kernel crashes on affected systems.
How do I fix CVE-2025-68322?
To fix CVE-2025-68322, you should update the Linux kernel to the latest stable version that contains the patch.
Which versions of the Linux kernel are affected by CVE-2025-68322?
CVE-2025-68322 affects versions of the Linux kernel prior to the patch being applied.
What impact does CVE-2025-68322 have on system stability?
CVE-2025-68322 can lead to potential crashes in the kernel, affecting overall system stability and reliability.
Is CVE-2025-68322 exploitable remotely?
CVE-2025-68322 is primarily a local issue related to unaligned access, making it less likely to be exploited remotely but still a concern for system users.