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authorAlexander Gordeev <agordeev@linux.ibm.com>2024-08-21 18:55:06 +0200
committerVasily Gorbik <gor@linux.ibm.com>2024-08-22 19:24:13 +0200
commitd7fd2941ae9a67423d1c7bee985f240e4686634f (patch)
treed296828efe994aa9b0187650848e3e247357fc88 /arch/s390/boot
parentb4f5bd60d558f6ba451d7e76aa05782c07a182a3 (diff)
s390/boot: Avoid possible physmem_info segment corruption
When physical memory for the kernel image is allocated it does not consider extra memory required for offsetting the image start to match it with the lower 20 bits of KASLR virtual base address. That might lead to kernel access beyond its memory range. Suggested-by: Vasily Gorbik <gor@linux.ibm.com> Fixes: 693d41f7c938 ("s390/mm: Restore mapping of kernel image using large pages") Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/boot')
-rw-r--r--arch/s390/boot/startup.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index cff34744b5a9..d69f1dfd3b1e 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -457,9 +457,9 @@ void startup_kernel(void)
*/
kaslr_large_page_offset = __kaslr_offset & ~_SEGMENT_MASK;
if (kaslr_enabled()) {
- unsigned long end = ident_map_size - kaslr_large_page_offset;
+ unsigned long size = kernel_size + kaslr_large_page_offset;
- __kaslr_offset_phys = randomize_within_range(kernel_size, _SEGMENT_SIZE, 0, end);
+ __kaslr_offset_phys = randomize_within_range(size, _SEGMENT_SIZE, 0, ident_map_size);
}
if (!__kaslr_offset_phys)
__kaslr_offset_phys = nokaslr_offset_phys;