From: Florian-Ewald Mueller florian-ewald.mueller@ionos.com
- limit bitmap chunk size internal u64 variable to values not overflowing the u32 bitmap superblock structure variable stored on persistent media - assign bitmap chunk size internal u64 variable from unsigned values to avoid possible sign extension artifacts when assigning from a s32 value
The bug has been there since at least kernel 4.0. Steps to reproduce it: 1: mdadm -C /dev/mdx -l 1 --bitmap=internal --bitmap-chunk=256M -e 1.2 -n2 /dev/rnbd1 /dev/rnbd2 2 resize member device rnbd1 and rnbd2 to 8 TB 3 mdadm --grow /dev/mdx --size=max
The bitmap_chunksize will overflow without patch.
Cc: stable@vger.kernel.org
Signed-off-by: Florian-Ewald Mueller florian-ewald.mueller@ionos.com Signed-off-by: Jack Wang jinpu.wang@ionos.com Signed-off-by: Song Liu song@kernel.org --- v3: fix build warning on i386. drivers/md/md-bitmap.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c index 63ece30114e5..e7cc6ba1b657 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -486,7 +486,7 @@ void md_bitmap_print_sb(struct bitmap *bitmap) sb = kmap_atomic(bitmap->storage.sb_page); pr_debug("%s: bitmap file superblock:\n", bmname(bitmap)); pr_debug(" magic: %08x\n", le32_to_cpu(sb->magic)); - pr_debug(" version: %d\n", le32_to_cpu(sb->version)); + pr_debug(" version: %u\n", le32_to_cpu(sb->version)); pr_debug(" uuid: %08x.%08x.%08x.%08x\n", le32_to_cpu(*(__le32 *)(sb->uuid+0)), le32_to_cpu(*(__le32 *)(sb->uuid+4)), @@ -497,11 +497,11 @@ void md_bitmap_print_sb(struct bitmap *bitmap) pr_debug("events cleared: %llu\n", (unsigned long long) le64_to_cpu(sb->events_cleared)); pr_debug(" state: %08x\n", le32_to_cpu(sb->state)); - pr_debug(" chunksize: %d B\n", le32_to_cpu(sb->chunksize)); - pr_debug(" daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep)); + pr_debug(" chunksize: %u B\n", le32_to_cpu(sb->chunksize)); + pr_debug(" daemon sleep: %us\n", le32_to_cpu(sb->daemon_sleep)); pr_debug(" sync size: %llu KB\n", (unsigned long long)le64_to_cpu(sb->sync_size)/2); - pr_debug("max write behind: %d\n", le32_to_cpu(sb->write_behind)); + pr_debug("max write behind: %u\n", le32_to_cpu(sb->write_behind)); kunmap_atomic(sb); }
@@ -2105,7 +2105,8 @@ int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks, bytes = DIV_ROUND_UP(chunks, 8); if (!bitmap->mddev->bitmap_info.external) bytes += sizeof(bitmap_super_t); - } while (bytes > (space << 9)); + } while (bytes > (space << 9) && (chunkshift + BITMAP_BLOCK_SHIFT) < + (BITS_PER_BYTE * sizeof(((bitmap_super_t *)0)->chunksize) - 1)); } else chunkshift = ffz(~chunksize) - BITMAP_BLOCK_SHIFT;
@@ -2150,7 +2151,7 @@ int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks, bitmap->counts.missing_pages = pages; bitmap->counts.chunkshift = chunkshift; bitmap->counts.chunks = chunks; - bitmap->mddev->bitmap_info.chunksize = 1 << (chunkshift + + bitmap->mddev->bitmap_info.chunksize = 1UL << (chunkshift + BITMAP_BLOCK_SHIFT);
blocks = min(old_counts.chunks << old_counts.chunkshift, @@ -2176,8 +2177,8 @@ int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks, bitmap->counts.missing_pages = old_counts.pages; bitmap->counts.chunkshift = old_counts.chunkshift; bitmap->counts.chunks = old_counts.chunks; - bitmap->mddev->bitmap_info.chunksize = 1 << (old_counts.chunkshift + - BITMAP_BLOCK_SHIFT); + bitmap->mddev->bitmap_info.chunksize = + 1UL << (old_counts.chunkshift + BITMAP_BLOCK_SHIFT); blocks = old_counts.chunks << old_counts.chunkshift; pr_warn("Could not pre-allocate in-memory bitmap for cluster raid\n"); break; @@ -2537,6 +2538,9 @@ chunksize_store(struct mddev *mddev, const char *buf, size_t len) if (csize < 512 || !is_power_of_2(csize)) return -EINVAL; + if (BITS_PER_LONG > 32 && csize >= (1ULL << (BITS_PER_BYTE * + sizeof(((bitmap_super_t *)0)->chunksize)))) + return -EOVERFLOW; mddev->bitmap_info.chunksize = csize; return len; }