6.6-stable review patch. If anyone has any objections, please let me know.
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From: Paulo Alcantara pc@manguebit.com
commit 0812340811e45ec4039d409049be53056182a552 upstream.
We can't use PATH_MAX for SMB symlinks because
(1) Windows Server will fail FSCTL_SET_REPARSE_POINT with STATUS_IO_REPARSE_DATA_INVALID when input buffer is larger than 16K, as specified in MS-FSA 2.1.5.10.37.
(2) The client won't be able to parse large SMB responses that includes SMB symlink path within SMB2_CREATE or SMB2_IOCTL responses.
Fix this by defining a maximum length value (4060) for SMB symlinks that both client and server can handle.
Cc: David Howells dhowells@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (Red Hat) pc@manguebit.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/smb/client/reparse.c | 5 ++++- fs/smb/client/reparse.h | 2 ++ 2 files changed, 6 insertions(+), 1 deletion(-)
--- a/fs/smb/client/reparse.c +++ b/fs/smb/client/reparse.c @@ -35,6 +35,9 @@ int smb2_create_reparse_symlink(const un u16 len, plen; int rc = 0;
+ if (strlen(symname) > REPARSE_SYM_PATH_MAX) + return -ENAMETOOLONG; + sym = kstrdup(symname, GFP_KERNEL); if (!sym) return -ENOMEM; @@ -64,7 +67,7 @@ int smb2_create_reparse_symlink(const un if (rc < 0) goto out;
- plen = 2 * UniStrnlen((wchar_t *)path, PATH_MAX); + plen = 2 * UniStrnlen((wchar_t *)path, REPARSE_SYM_PATH_MAX); len = sizeof(*buf) + plen * 2; buf = kzalloc(len, GFP_KERNEL); if (!buf) { --- a/fs/smb/client/reparse.h +++ b/fs/smb/client/reparse.h @@ -12,6 +12,8 @@ #include "fs_context.h" #include "cifsglob.h"
+#define REPARSE_SYM_PATH_MAX 4060 + /* * Used only by cifs.ko to ignore reparse points from files when client or * server doesn't support FSCTL_GET_REPARSE_POINT.