diff options
| author | Pingfan Liu <piliu@redhat.com> | 2025-12-16 09:48:52 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-12-23 11:23:14 -0800 |
| commit | a3785ae5d334bb71d47a593d54c686a03fb9d136 (patch) | |
| tree | 0fb88587073e8c89fafe16e890dd72d80207d992 | |
| parent | fe55ea85939efcbf0e6baa234f0d70acb79e7b58 (diff) | |
kernel/kexec: fix IMA when allocation happens in CMA area
*** Bug description ***
When I tested kexec with the latest kernel, I ran into the following warning:
[ 40.712410] ------------[ cut here ]------------
[ 40.712576] WARNING: CPU: 2 PID: 1562 at kernel/kexec_core.c:1001 kimage_map_segment+0x144/0x198
[...]
[ 40.816047] Call trace:
[ 40.818498] kimage_map_segment+0x144/0x198 (P)
[ 40.823221] ima_kexec_post_load+0x58/0xc0
[ 40.827246] __do_sys_kexec_file_load+0x29c/0x368
[...]
[ 40.855423] ---[ end trace 0000000000000000 ]---
*** How to reproduce ***
This bug is only triggered when the kexec target address is allocated in
the CMA area. If no CMA area is reserved in the kernel, use the "cma="
option in the kernel command line to reserve one.
*** Root cause ***
The commit 07d24902977e ("kexec: enable CMA based contiguous
allocation") allocates the kexec target address directly on the CMA area
to avoid copying during the jump. In this case, there is no IND_SOURCE
for the kexec segment. But the current implementation of
kimage_map_segment() assumes that IND_SOURCE pages exist and map them
into a contiguous virtual address by vmap().
*** Solution ***
If IMA segment is allocated in the CMA area, use its page_address()
directly.
Link: https://lkml.kernel.org/r/20251216014852.8737-2-piliu@redhat.com
Fixes: 07d24902977e ("kexec: enable CMA based contiguous allocation")
Signed-off-by: Pingfan Liu <piliu@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Steven Chen <chenste@linux.microsoft.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Roberto Sassu <roberto.sassu@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | kernel/kexec_core.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 1a79c5b18d8f..95c585c6ddc3 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -960,13 +960,17 @@ void *kimage_map_segment(struct kimage *image, int idx) kimage_entry_t *ptr, entry; struct page **src_pages; unsigned int npages; + struct page *cma; void *vaddr = NULL; int i; + cma = image->segment_cma[idx]; + if (cma) + return page_address(cma); + addr = image->segment[idx].mem; size = image->segment[idx].memsz; eaddr = addr + size; - /* * Collect the source pages and map them in a contiguous VA range. */ @@ -1007,7 +1011,8 @@ void *kimage_map_segment(struct kimage *image, int idx) void kimage_unmap_segment(void *segment_buffer) { - vunmap(segment_buffer); + if (is_vmalloc_addr(segment_buffer)) + vunmap(segment_buffer); } struct kexec_load_limit { |