nsfs: fix u32-vs-bytes unit mismatch in nsfs_fh_to_dentry() - #2644
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In nsfs_fh_to_dentry(), both fh_len and NSFS_FID_SIZE_U32_LATEST (4) are expressed in units of 4-byte u32 words rather than bytes, whereas pointer arithmetic on (void *)fid and the byte count passed to memchr_inv() are in bytes (NSFS_FILE_HANDLE_SIZE_LATEST = 16). Passing (void *)fid + NSFS_FID_SIZE_U32_LATEST and fh_len - NSFS_FID_SIZE_U32_LATEST to memchr_inv() inspects bytes [4 .. fh_len) inside struct nsfs_file_handle (fid->ns_id and fid->ns_type) instead of the trailing bytes [16 .. fh_len * 4) after struct nsfs_file_handle. Consequently: 1. Valid zero-padded handles with handle_bytes >= 36 (fh_len >= 9) where fid->ns_type != 0 (at byte offset 8) are falsely rejected with -ESTALE. 2. Non-zero trailing garbage in bytes [16 .. fh_len * 4) is ignored when the upper 32 bits of fid->ns_id (bytes [4..7]) are zero. Fix this by offsetting (void *)fid by NSFS_FILE_HANDLE_SIZE_LATEST (16) and multiplying (fh_len - NSFS_FID_SIZE_U32_LATEST) by sizeof(u32). Fixes: 5222470 ("nsfs: support file handles") Assisted-by: LLM Signed-off-by: Hui Peng <benquike@gmail.com>
…to_dentry() In nsfs_fh_to_dentry(), ns_get_unless_inactive(ns) acquires an active reference to ns before switching on ns->ns_type. Unlike the CLONE_NEWPID error path and the owning_ns permission error path, the default: branch returns ERR_PTR(-EOPNOTSUPP) without calling ns->ops->put(ns), leaking the namespace reference. Call ns->ops->put(ns) before returning ERR_PTR(-EOPNOTSUPP) in the default: branch. Fixes: 5222470 ("nsfs: support file handles") Assisted-by: LLM Signed-off-by: Hui Peng <benquike@gmail.com>
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Superseded by series 1169168 (v1). Closing automatically. Automated by ml2pr |
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Series: https://patchwork.kernel.org/project/linux-fsdevel/list/?series=1169233
Submitter: Hui Peng
Version: 2
Patches: 2/2
Message-ID:
<20260919112519.3872163-1-benquike@gmail.com>Base: vfs.base.ci
Lore: https://lore.kernel.org/linux-fsdevel/20260919112519.3872163-1-benquike@gmail.com
Automated by ml2pr