From: Florian-Ewald Mueller <florian-ewald.mueller@xxxxxxxxx>
- 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@xxxxxxxxxxxxxxx
Signed-off-by: Florian-Ewald Mueller <florian-ewald.mueller@xxxxxxxxx>
Signed-off-by: Jack Wang <jinpu.wang@xxxxxxxxx>
---
v1->v2: extend commit message for steps to reproduce the problem.
fix the warning reported by buildbot
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 bf6dffadbe6f..d4bf7f603ef6 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;
@@ -2534,6 +2535,9 @@ chunksize_store(struct mddev *mddev, const char *buf, size_t len)
if (csize < 512 ||
!is_power_of_2(csize))
return -EINVAL;
+ if (csize >= (1ULL << (BITS_PER_BYTE *
+ sizeof(((bitmap_super_t *)0)->chunksize))))
+ return -EOVERFLOW;
mddev->bitmap_info.chunksize = csize;
return len;
}
--
2.34.1
