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| author | Li Zhong <floridsleeves@gmail.com> | 2022-09-16 16:33:05 -0700 |
|---|---|---|
| committer | Song Liu <song@kernel.org> | 2022-11-14 09:35:49 -0800 |
| commit | 3bd548e5b819b8c0f2c9085de775c5c7bff9052f (patch) | |
| tree | f6a8bf47de5de4b17adeffd72ade8ca7b8df991e /drivers/md | |
| parent | 4f8126bb2308066b877859e4b5923ffb54143630 (diff) | |
| download | linux-3bd548e5b819b8c0f2c9085de775c5c7bff9052f.tar.bz2 | |
drivers/md/md-bitmap: check the return value of md_bitmap_get_counter()
Check the return value of md_bitmap_get_counter() in case it returns
NULL pointer, which will result in a null pointer dereference.
v2: update the check to include other dereference
Signed-off-by: Li Zhong <floridsleeves@gmail.com>
Signed-off-by: Song Liu <song@kernel.org>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/md-bitmap.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c index bf6dffadbe6f..63ece30114e5 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -2195,20 +2195,23 @@ int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks, if (set) { bmc_new = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1); - if (*bmc_new == 0) { - /* need to set on-disk bits too. */ - sector_t end = block + new_blocks; - sector_t start = block >> chunkshift; - start <<= chunkshift; - while (start < end) { - md_bitmap_file_set_bit(bitmap, block); - start += 1 << chunkshift; + if (bmc_new) { + if (*bmc_new == 0) { + /* need to set on-disk bits too. */ + sector_t end = block + new_blocks; + sector_t start = block >> chunkshift; + + start <<= chunkshift; + while (start < end) { + md_bitmap_file_set_bit(bitmap, block); + start += 1 << chunkshift; + } + *bmc_new = 2; + md_bitmap_count_page(&bitmap->counts, block, 1); + md_bitmap_set_pending(&bitmap->counts, block); } - *bmc_new = 2; - md_bitmap_count_page(&bitmap->counts, block, 1); - md_bitmap_set_pending(&bitmap->counts, block); + *bmc_new |= NEEDED_MASK; } - *bmc_new |= NEEDED_MASK; if (new_blocks < old_blocks) old_blocks = new_blocks; } |