Description
In the Linux kernel, the following vulnerability has been resolved: nios2: ensure that memblock.current_limit is set when setting pfn limits On nios2, with CONFIG_FLATMEM set, the kernel relies on memblock_get_current_limit() to determine the limits of mem_map, in particular for max_low_pfn. Unfortunately, memblock.current_limit is only default initialized to MEMBLOCK_ALLOC_ANYWHERE at this point of the bootup, potentially leading to situations where max_low_pfn can erroneously exceed the value of max_pfn and, thus, the valid range of available DRAM. This can in turn cause kernel-level paging failures, e.g.: [ 76.900000] Unable to handle kernel paging request at virtual address 20303000 [ 76.900000] ea = c0080890, ra = c000462c, cause = 14 [ 76.900000] Kernel panic - not syncing: Oops [ 76.900000] ---[ end Kernel panic - not syncing: Oops ]--- This patch fixes this by pre-calculating memblock.current_limit based on the upper limits of the available memory ranges via adjust_lowmem_bounds, a simplified version of the equivalent implementation within the arm architecture.
Product status
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before 25f09699edd360b534ccae16bc276c3b52c471f3
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before 5c3e38a367822f036227dd52bac82dc4a05157e2
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before b1ec9faef7e36269ca3ec890972a78effbaeb975
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before 90f5f715550e07cd6a51f80fc3f062d832c8c997
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before 8912814f14e298b83df072fecc1f7ed1b63b1b2c
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before a20b83cf45be2057f3d073506779e52c7fa17f94
5.15.196 (semver)
6.1.158 (semver)
6.6.115 (semver)
6.12.56 (semver)
6.17.6 (semver)
6.18 (original_commit_for_fix)
References
git.kernel.org/...c/25f09699edd360b534ccae16bc276c3b52c471f3
git.kernel.org/...c/5c3e38a367822f036227dd52bac82dc4a05157e2
git.kernel.org/...c/b1ec9faef7e36269ca3ec890972a78effbaeb975
git.kernel.org/...c/90f5f715550e07cd6a51f80fc3f062d832c8c997
git.kernel.org/...c/8912814f14e298b83df072fecc1f7ed1b63b1b2c
git.kernel.org/...c/a20b83cf45be2057f3d073506779e52c7fa17f94
