From 346314bb0cc2fc52b50b73d6ecc62e0217455c2e Mon Sep 17 00:00:00 2001 From: Zhang Cen Date: Thu, 28 May 2026 23:12:47 +0800 Subject: [PATCH] ocfs2: reject FITRIM ranges shorter than a cluster [ Upstream commit ca1afd88f5eaaff9168e1466e5401385edf59543 ] ocfs2_trim_mainbm() trims the global bitmap in cluster units, but its too-short range validation only checks sb->s_blocksize. On filesystems with a cluster size larger than the block size, a FITRIM range that is at least one block but shorter than one cluster is accepted and shifted down to len == 0. The later start + len - 1 and len -= ... arithmetic then underflows and can drive trimming past the requested range. Reject ranges shorter than s_clustersize instead. That preserves the existing -EINVAL behavior for requests that cannot discard even one allocation unit and keeps zero-cluster trims out of the group walk. Link: https://lore.kernel.org/20260528151247.361854-1-rollkingzzc@gmail.com Fixes: aa89762c5480 ("ocfs2: return EINVAL if the given range to discard is less than block size") Assisted-by: Codex:gpt-5.5 Signed-off-by: Zhang Cen Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Cc: Heming Zhao Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- fs/ocfs2/alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c index af40f0da3a95..bcdd9f25b2f5 100644 --- a/fs/ocfs2/alloc.c +++ b/fs/ocfs2/alloc.c @@ -7546,7 +7546,7 @@ int ocfs2_trim_mainbm(struct super_block *sb, struct fstrim_range *range) len = range->len >> osb->s_clustersize_bits; minlen = range->minlen >> osb->s_clustersize_bits; - if (minlen >= osb->bitmap_cpg || range->len < sb->s_blocksize) + if (minlen >= osb->bitmap_cpg || range->len < osb->s_clustersize) return -EINVAL; trace_ocfs2_trim_mainbm(start, len, minlen);