Message ID | 20240928215948.4494-4-pali@kernel.org (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | cifs: Fix support for NFS-style reparse points | expand |
diff --git a/fs/smb/client/reparse.h b/fs/smb/client/reparse.h index 2c0644bc4e65..790360f8a53b 100644 --- a/fs/smb/client/reparse.h +++ b/fs/smb/client/reparse.h @@ -20,9 +20,12 @@ static inline dev_t reparse_nfs_mkdev(struct reparse_posix_data *buf) { - u64 v = le64_to_cpu(*(__le64 *)buf->DataBuffer); + u32 major, minor; - return MKDEV(v >> 32, v & 0xffffffff); + major = le32_to_cpu(((__le32 *)buf->DataBuffer)[0]); + minor = le32_to_cpu(((__le32 *)buf->DataBuffer)[1]); + + return MKDEV(major, minor); } static inline dev_t wsl_mkdev(void *ptr)
Linux SMB client currently parses NFS-style char and block devices incorrectly. It reads major number from location of minor and major from location of minor. Per MS-FSCC 2.1.2.6 NFS_SPECFILE_CHR and NFS_SPECFILE_BLK DataBuffer's field contains two 32-bit integers that represent major and minor device numbers. So the first one 32-bit integer in DataBuffer is major number and second one in DataBuffer is minor number. Microsoft Windows NFS server reads them in this order too. This issue was introduced in commit 45e724022e27 ("smb: client: set correct file type from NFS reparse points") and probably because in commit message was test of char and block devices with same major and minor numbers. So swapped major and minor numbers were not spotted. Fix this problem in Linux SMB client by reading major and minor numbers from correct position of DataBuffer. This change fixes interoperability of char and block devices on Windows share which is exported over both SMB and NFS protocols. Fixes: 45e724022e27 ("smb: client: set correct file type from NFS reparse points") Signed-off-by: Pali Rohár <pali@kernel.org> --- fs/smb/client/reparse.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)