[PATCH 2/7] Cygwin: fix fstatvfs on sockets that are not socket files
Ken Brown
kbrown@cornell.edu
Thu Feb 25 22:48:07 GMT 2021
If fstatvfs(2) is called on an AF_LOCAL or AF_UNIX socket that is not
a socket file, the current code calls fhandler_disk_file::fstatvfs in
most cases. The latter expects to be operating on a disk file and
uses the socket's io_handle, which is not a file handle.
Fix this by calling fhandler_disk_file::fstatvfs only if the
fhandler_socket object is a socket file (determined by testing
dev().isfs()).
---
winsup/cygwin/fhandler_socket_local.cc | 5 ++++-
winsup/cygwin/fhandler_socket_unix.cc | 14 +++++++++++---
2 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/winsup/cygwin/fhandler_socket_local.cc b/winsup/cygwin/fhandler_socket_local.cc
index f8adf6c46..5ca6d8550 100644
--- a/winsup/cygwin/fhandler_socket_local.cc
+++ b/winsup/cygwin/fhandler_socket_local.cc
@@ -690,8 +690,11 @@ fhandler_socket_local::fstat (struct stat *buf)
int __reg2
fhandler_socket_local::fstatvfs (struct statvfs *sfs)
{
- if (get_sun_path () && get_sun_path ()[0] == '\0')
+ if (!dev ().isfs ())
+ /* fstatvfs called on a socket. */
return fhandler_socket_wsock::fstatvfs (sfs);
+
+ /* statvfs on a socket file or fstatvfs on a socket opened w/ O_PATH. */
if (get_flags () & O_PATH)
/* We already have a handle. */
{
diff --git a/winsup/cygwin/fhandler_socket_unix.cc b/winsup/cygwin/fhandler_socket_unix.cc
index 8091fa820..06db929ed 100644
--- a/winsup/cygwin/fhandler_socket_unix.cc
+++ b/winsup/cygwin/fhandler_socket_unix.cc
@@ -2354,10 +2354,18 @@ fhandler_socket_unix::fstat (struct stat *buf)
int __reg2
fhandler_socket_unix::fstatvfs (struct statvfs *sfs)
{
- if (sun_path ()
- && (sun_path ()->un_len <= (socklen_t) sizeof (sa_family_t)
- || sun_path ()->un.sun_path[0] == '\0'))
+ if (!dev ().isfs ())
+ /* fstatvfs called on a socket. */
return fhandler_socket::fstatvfs (sfs);
+
+ /* statvfs on a socket file or fstatvfs on a socket opened w/ O_PATH. */
+ if (get_flags () & O_PATH)
+ /* We already have a handle. */
+ {
+ HANDLE h = get_handle ();
+ if (h)
+ return fstatvfs_by_handle (h, sfs);
+ }
fhandler_disk_file fh (pc);
fh.get_device () = FH_FS;
return fh.fstatvfs (sfs);
--
2.30.0
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