Fix off_t overflow in pg_basebackup on Windows.

macdice · macdice · commit bd0564f61d37 · 2025-01-09T16:05:36.000+13:00
walmethods.c used off_t to navigate around a pg_wal.tar file that could exceed 2GB, which doesn't work on Windows and would fail with misleading errors. Use pgoff_t instead. Back-patch to all supported branches. Author: Davinder Singh <davinder.singh@enterprisedb.com> Reported-by: Jakub Wartak <jakub.wartak@enterprisedb.com> Discussion: https://postgr.es/m/CAKZiRmyM4YnokK6Oenw5JKwAQ3rhP0YTz2T-tiw5dAQjGRXE3Q%40mail.gmail.com
diff --git a/src/bin/pg_basebackup/receivelog.c b/src/bin/pg_basebackup/receivelog.c
@@ -191,7 +191,7 @@ open_walfile(StreamCtl *stream, XLogRecPtr startpoint)
 static bool
 close_walfile(StreamCtl *stream, XLogRecPtr pos)
 {
-	off_t		currpos;
+	pgoff_t		currpos;
 	int			r;
 
 	if (walfile == NULL)
diff --git a/src/bin/pg_basebackup/walmethods.c b/src/bin/pg_basebackup/walmethods.c
@@ -55,7 +55,7 @@ static DirectoryMethodData *dir_data = NULL;
 typedef struct DirectoryMethodFile
 {
 	int			fd;
-	off_t		currpos;
+	pgoff_t		currpos;
 	char	   *pathname;
 	char	   *fullpath;
 	char	   *temp_suffix;
@@ -241,7 +241,7 @@ dir_write(Walfile f, const void *buf, size_t count)
 	return r;
 }
 
-static off_t
+static pgoff_t
 dir_get_current_pos(Walfile f)
 {
 	Assert(f != NULL);
@@ -468,8 +468,8 @@ FreeWalDirectoryMethod(void)
 
 typedef struct TarMethodFile
 {
-	off_t		ofs_start;		/* Where does the *header* for this file start */
-	off_t		currpos;
+	pgoff_t		ofs_start;		/* Where does the *header* for this file start */
+	pgoff_t		currpos;
 	char		header[512];
 	char	   *pathname;
 	size_t		pad_to_size;
@@ -799,7 +799,7 @@ tar_compression(void)
 	return tar_data->compression;
 }
 
-static off_t
+static pgoff_t
 tar_get_current_pos(Walfile f)
 {
 	Assert(f != NULL);
diff --git a/src/bin/pg_basebackup/walmethods.h b/src/bin/pg_basebackup/walmethods.h
@@ -68,7 +68,7 @@ struct WalWriteMethod
 	ssize_t		(*write) (Walfile f, const void *buf, size_t count);
 
 	/* Return the current position in a file or -1 on error */
-	off_t		(*get_current_pos) (Walfile f);
+	pgoff_t		(*get_current_pos) (Walfile f);
 
 	/*
 	 * fsync the contents of the specified file. Returns 0 on success.

Original file line number	Diff line number	Diff line change
`@@ -191,7 +191,7 @@ open_walfile(StreamCtl *stream, XLogRecPtr startpoint)`
`191`	`191`	`static bool`
`192`	`192`	`close_walfile(StreamCtl *stream, XLogRecPtr pos)`
`193`	`193`	`{`
`194`		`- off_t currpos;`
	`194`	`+ pgoff_t currpos;`
`195`	`195`	`int r;`
`196`	`196`
`197`	`197`	`if (walfile == NULL)`
Original file line number	Diff line number	Diff line change
`@@ -55,7 +55,7 @@ static DirectoryMethodData *dir_data = NULL;`
`55`	`55`	`typedef struct DirectoryMethodFile`
`56`	`56`	`{`
`57`	`57`	`int fd;`
`58`		`- off_t currpos;`
	`58`	`+ pgoff_t currpos;`
`59`	`59`	`char *pathname;`
`60`	`60`	`char *fullpath;`
`61`	`61`	`char *temp_suffix;`
`@@ -241,7 +241,7 @@ dir_write(Walfile f, const void *buf, size_t count)`
`241`	`241`	`return r;`
`242`	`242`	`}`
`243`	`243`
`244`		`-static off_t`
	`244`	`+static pgoff_t`
`245`	`245`	`dir_get_current_pos(Walfile f)`
`246`	`246`	`{`
`247`	`247`	`Assert(f != NULL);`
`@@ -468,8 +468,8 @@ FreeWalDirectoryMethod(void)`
`468`	`468`
`469`	`469`	`typedef struct TarMethodFile`
`470`	`470`	`{`
`471`		`- off_t ofs_start; /* Where does the header for this file start */`
`472`		`- off_t currpos;`
	`471`	`+ pgoff_t ofs_start; /* Where does the header for this file start */`
	`472`	`+ pgoff_t currpos;`
`473`	`473`	`char header[512];`
`474`	`474`	`char *pathname;`
`475`	`475`	`size_t pad_to_size;`
`@@ -799,7 +799,7 @@ tar_compression(void)`
`799`	`799`	`return tar_data->compression;`
`800`	`800`	`}`
`801`	`801`
`802`		`-static off_t`
	`802`	`+static pgoff_t`
`803`	`803`	`tar_get_current_pos(Walfile f)`
`804`	`804`	`{`
`805`	`805`	`Assert(f != NULL);`