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authorDuoming Zhou <duoming@zju.edu.cn>2024-03-12 08:59:05 +0800
committerAndrew Morton <akpm@linux-foundation.org>2024-04-25 20:55:48 -0700
commitc2af060d1c18beaec56351cf9c9bcbbc5af341a3 (patch)
tree6e56ef09b824bbd3bdeffa411e1b6bf15d9d6bc0
parent4196b48ddd382419e51658bf94a25af195ba9450 (diff)
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lib/test_hmm.c: handle src_pfns and dst_pfns allocation failure
The kcalloc() in dmirror_device_evict_chunk() will return null if the physical memory has run out. As a result, if src_pfns or dst_pfns is dereferenced, the null pointer dereference bug will happen. Moreover, the device is going away. If the kcalloc() fails, the pages mapping a chunk could not be evicted. So add a __GFP_NOFAIL flag in kcalloc(). Finally, as there is no need to have physically contiguous memory, Switch kcalloc() to kvcalloc() in order to avoid failing allocations. Link: https://lkml.kernel.org/r/20240312005905.9939-1-duoming@zju.edu.cn Fixes: b2ef9f5a5cb3 ("mm/hmm/test: add selftest driver for HMM") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Cc: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--lib/test_hmm.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index 717dcb830127..b823ba7cb6a1 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -1226,8 +1226,8 @@ static void dmirror_device_evict_chunk(struct dmirror_chunk *chunk)
unsigned long *src_pfns;
unsigned long *dst_pfns;
- src_pfns = kcalloc(npages, sizeof(*src_pfns), GFP_KERNEL);
- dst_pfns = kcalloc(npages, sizeof(*dst_pfns), GFP_KERNEL);
+ src_pfns = kvcalloc(npages, sizeof(*src_pfns), GFP_KERNEL | __GFP_NOFAIL);
+ dst_pfns = kvcalloc(npages, sizeof(*dst_pfns), GFP_KERNEL | __GFP_NOFAIL);
migrate_device_range(src_pfns, start_pfn, npages);
for (i = 0; i < npages; i++) {
@@ -1250,8 +1250,8 @@ static void dmirror_device_evict_chunk(struct dmirror_chunk *chunk)
}
migrate_device_pages(src_pfns, dst_pfns, npages);
migrate_device_finalize(src_pfns, dst_pfns, npages);
- kfree(src_pfns);
- kfree(dst_pfns);
+ kvfree(src_pfns);
+ kvfree(dst_pfns);
}
/* Removes free pages from the free list so they can't be re-allocated */