6.15-stable review patch. If anyone has any objections, please let me know.
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From: Håkon Bugge haakon.bugge@oracle.com
commit c17fb542dbd1db745c9feac15617056506dd7195 upstream.
The commit message of commit 6ec1f0239485 ("md/md-bitmap: fix stats collection for external bitmaps") states:
Remove the external bitmap check as the statistics should be available regardless of bitmap storage location.
Return -EINVAL only for invalid bitmap with no storage (neither in superblock nor in external file).
But, the code does not adhere to the above, as it does only check for a valid super-block for "internal" bitmaps. Hence, we observe:
Oops: GPF, probably for non-canonical address 0x1cd66f1f40000028 RIP: 0010:bitmap_get_stats+0x45/0xd0 Call Trace:
seq_read_iter+0x2b9/0x46a seq_read+0x12f/0x180 proc_reg_read+0x57/0xb0 vfs_read+0xf6/0x380 ksys_read+0x6d/0xf0 do_syscall_64+0x8c/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e
We fix this by checking the existence of a super-block for both the internal and external case.
Fixes: 6ec1f0239485 ("md/md-bitmap: fix stats collection for external bitmaps") Cc: stable@vger.kernel.org Reported-by: Gerald Gibson gerald.gibson@oracle.com Signed-off-by: Håkon Bugge haakon.bugge@oracle.com Link: https://lore.kernel.org/linux-raid/20250702091035.2061312-1-haakon.bugge@ora... Signed-off-by: Yu Kuai yukuai3@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/md-bitmap.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -2357,8 +2357,7 @@ static int bitmap_get_stats(void *data,
if (!bitmap) return -ENOENT; - if (!bitmap->mddev->bitmap_info.external && - !bitmap->storage.sb_page) + if (!bitmap->storage.sb_page) return -EINVAL; sb = kmap_local_page(bitmap->storage.sb_page); stats->sync_size = le64_to_cpu(sb->sync_size);