Linux Kernel vmalloc Memory Mapping Fix in mm/vmalloc.c

From this webpage screenshot, the following key information about the vulnerability can be obtained: 1. Vulnerability Description: - Issue: The function, when allocating high-order memory, attempts to fall back to low-order (order 0) allocation if the high-order allocation fails. However, this fallback may result in incorrect memory mapping, leading to memory corruption. - Cause: The function assumes that its parameter has uniform page offsets. If includes and the allocation in fails, it may result in pages with different offsets, causing incorrect mapping. 2. Fix: - Solution: Remove the fallback code that attempts low-order allocation when high-order allocation fails. Since will attempt low-order allocation if needed, the fallback in is redundant and unnecessary. - Code Change: The fallback code for low-order allocation has been removed. 3. Patch Link: - Link: https://lkml.kernel.org/r/20240808122019.3361-1-hailong.liu@oppo.com 4. Fix History: - Commit: e93c3da4d86e - Reporter: Hailong Liu - Reviewers: Tangquan Zheng, Baoquan He, Uladislau Rezki, Barry Song, Michal Hocko, Matthew Wilcox, Andrew Morton, Greg Kroah-Hartman 5. Patch Content: - File: - Modification Location: Lines -2992,15 +2992,8 - Code Changes: - Description: The fallback code for low-order allocation has been removed. This information indicates that the vulnerability is related to incorrect memory mapping, and the fix involves removing redundant fallback logic to prevent erroneous memory mappings.

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Linux Kernel vmalloc Memory Mapping Fix in mm/vmalloc.c