From d40c24634fe077a0dc91fd11fccf44ce12b454d5 Mon Sep 17 00:00:00 2001 From: Guangshuo Li Date: Sun, 5 Jul 2026 19:34:35 +0800 Subject: [PATCH] ksmbd: Do not skip lock checks for single-byte ranges check_lock_range() uses inclusive ranges. Its callers pass the end offset as start + length - 1, so start == end represents a valid single-byte range rather than an empty range. The start == end shortcut therefore skips mandatory byte-range lock checks for one-byte reads, writes, copychunk operations and one-byte truncate ranges. A conflicting lock covering that byte is not checked and the operation is allowed to proceed. Remove the shortcut. The truncate size == inode->i_size case is already handled by only calling check_lock_range() when the new size differs from the current file size. Fixes: 5d510ac31626 ("ksmbd: skip lock-range check on equal size to avoid size==0 underflow") Signed-off-by: Guangshuo Li Signed-off-by: Namjae Jeon --- fs/smb/server/vfs.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c index 86d9cda0ca9e..6600c2f5a404 100644 --- a/fs/smb/server/vfs.c +++ b/fs/smb/server/vfs.c @@ -297,9 +297,6 @@ static int check_lock_range(struct file *filp, loff_t start, loff_t end, struct file_lock_context *ctx = locks_inode_context(file_inode(filp)); int error = 0; - if (start == end) - return 0; - if (!ctx || list_empty_careful(&ctx->flc_posix)) return 0;