# \[PATCH 6.1 1034/1191\] ksmbd: Do not skip lock checks for single-byte ranges - From: Greg Kroah-Hartman \ - Date: 2026-09-12 16:46:50 - List: stable - Page: https://ratatoskr.run/stable/2026/09/17565331 - Thread: https://ratatoskr.run/stable/2026/09/17564182/t/14.md ```text 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guangshuo Li [ Upstream commit d40c24634fe077a0dc91fd11fccf44ce12b454d5 ] 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 Signed-off-by: Sasha Levin --- 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 1834dd4f255ec..2915f7e98fe93 100644 --- a/fs/smb/server/vfs.c +++ b/fs/smb/server/vfs.c @@ -330,9 +330,6 @@ static int check_lock_range(struct file *filp, loff_t start, loff_t end, struct file_lock_context *ctx = file_inode(filp)->i_flctx; int error = 0; - if (start == end) - return 0; - if (!ctx || list_empty_careful(&ctx->flc_posix)) return 0; -- 2.53.0 ```