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| author | Li Zhong <floridsleeves@gmail.com> | 2022-09-16 16:33:05 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-12-31 13:33:01 +0100 |
| commit | 99bef41f8e8d1d52b5cb34f2f193f1346192752b (patch) | |
| tree | fc8733338b9504e4c06d7f5c55140b588b5ba36e | |
| parent | 302c0a8ed3bcf32e251990e74e24bd33d66d3df6 (diff) | |
| download | linux-stable-99bef41f8e8d1d52b5cb34f2f193f1346192752b.tar.gz linux-stable-99bef41f8e8d1d52b5cb34f2f193f1346192752b.tar.bz2 linux-stable-99bef41f8e8d1d52b5cb34f2f193f1346192752b.zip | |
drivers/md/md-bitmap: check the return value of md_bitmap_get_counter()
[ Upstream commit 3bd548e5b819b8c0f2c9085de775c5c7bff9052f ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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; } |