diff options
| author | Pasha Tatashin <pasha.tatashin@soleen.com> | 2026-02-26 01:38:57 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-04-05 23:53:06 +0300 |
| commit | 019fc36872374db6fd35e118c9e935374404bfbf (patch) | |
| tree | 845a44db9832e2330e054ca8a0b5fdc44e2a1c9c | |
| parent | ec106365394dc6c4e9ecf00842186d367dcc955a (diff) | |
| download | linux-019fc36872374db6fd35e118c9e935374404bfbf.tar.xz | |
kho: fix KASAN support for restored vmalloc regions
Restored vmalloc regions are currently not properly marked for KASAN,
causing KASAN to treat accesses to these regions as out-of-bounds.
Fix this by properly unpoisoning the restored vmalloc area using
kasan_unpoison_vmalloc(). This requires setting the VM_UNINITIALIZED flag
during the initial area allocation and clearing it after the pages have
been mapped and unpoisoned, using the clear_vm_uninitialized_flag()
helper.
Link: https://lkml.kernel.org/r/20260225223857.1714801-3-pasha.tatashin@soleen.com
Fixes: a667300bd53f ("kho: add support for preserving vmalloc allocations")
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reported-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org>
Tested-by: Pratyush Yadav (Google) <pratyush@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | kernel/liveupdate/kexec_handover.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c index 410098bae0bf..747a35107c84 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -14,6 +14,7 @@ #include <linux/cma.h> #include <linux/kmemleak.h> #include <linux/count_zeros.h> +#include <linux/kasan.h> #include <linux/kexec.h> #include <linux/kexec_handover.h> #include <linux/kho_radix_tree.h> @@ -1077,6 +1078,7 @@ EXPORT_SYMBOL_GPL(kho_unpreserve_vmalloc); void *kho_restore_vmalloc(const struct kho_vmalloc *preservation) { struct kho_vmalloc_chunk *chunk = KHOSER_LOAD_PTR(preservation->first); + kasan_vmalloc_flags_t kasan_flags = KASAN_VMALLOC_PROT_NORMAL; unsigned int align, order, shift, vm_flags; unsigned long total_pages, contig_pages; unsigned long addr, size; @@ -1128,7 +1130,8 @@ void *kho_restore_vmalloc(const struct kho_vmalloc *preservation) goto err_free_pages_array; area = __get_vm_area_node(total_pages * PAGE_SIZE, align, shift, - vm_flags, VMALLOC_START, VMALLOC_END, + vm_flags | VM_UNINITIALIZED, + VMALLOC_START, VMALLOC_END, NUMA_NO_NODE, GFP_KERNEL, __builtin_return_address(0)); if (!area) @@ -1143,6 +1146,13 @@ void *kho_restore_vmalloc(const struct kho_vmalloc *preservation) area->nr_pages = total_pages; area->pages = pages; + if (vm_flags & VM_ALLOC) + kasan_flags |= KASAN_VMALLOC_VM_ALLOC; + + area->addr = kasan_unpoison_vmalloc(area->addr, total_pages * PAGE_SIZE, + kasan_flags); + clear_vm_uninitialized_flag(area); + return area->addr; err_free_vm_area: |