Attachment 198620 Details for Bug 222796 – gets removal commit candidate

[patch] gets removal commit candidate

no-gets.diff (text/plain), 6.31 KB, created by Ed Maste on 2018-10-25 13:58:47 UTC

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Creator: Ed Maste

Created: 2018-10-25 13:58:47 UTC

Size: 6.31 KB

patch

obsolete

>commit 9eab9236c4bcbb859911affd95ec0d45ed0078ed
>Author: Ed Maste <emaste@freebsd.org>
>Date:   Thu Oct 5 11:19:15 2017 -0400
>
>    libc: remove gets
>    
>    gets is unsafe and shouldn't be used (for many years).  Leave it in the
>    existing symbol version so anything that previously linked aginst it
>    still runs, but do not allow new software to link against it.
>    
>    (The compatability/legacy implementation must not be static so that
>    the symbol and in particular the compat sym gets@FBSD_1.0 make it
>    into libc.)
>    
>    PR:             222796 (exp-run)
>    Reported by:    Paul Vixie
>    Reviewed by:    allanjude, cy, eadler, gnn, kib, ngie (some earlier)
>    Differential Revision:  https://reviews.freebsd.org/D12298
>
>diff --git a/contrib/libc++/include/cstdio b/contrib/libc++/include/cstdio
>index 00b989fad7c8..6b69f5e89c17 100644
>--- a/contrib/libc++/include/cstdio
>+++ b/contrib/libc++/include/cstdio
>@@ -74,7 +74,6 @@ int fputc(int c, FILE* stream);
> int fputs(const char* restrict s, FILE* restrict stream);
> int getc(FILE* stream);
> int getchar(void);
>-char* gets(char* s);  // removed in C++14
> int putc(int c, FILE* stream);
> int putchar(int c);
> int puts(const char* s);
>@@ -153,9 +152,6 @@ using ::tmpnam;
> 
> #ifndef _LIBCPP_HAS_NO_STDIN
> using ::getchar;
>-#if _LIBCPP_STD_VER <= 11 && !defined(_LIBCPP_MSVCRT)
>-using ::gets;
>-#endif
> using ::scanf;
> using ::vscanf;
> #endif
>diff --git a/contrib/netbsd-tests/lib/libc/ssp/h_gets.c b/contrib/netbsd-tests/lib/libc/ssp/h_gets.c
>index 8c601b0a8c5c..b809b175def7 100644
>--- a/contrib/netbsd-tests/lib/libc/ssp/h_gets.c
>+++ b/contrib/netbsd-tests/lib/libc/ssp/h_gets.c
>@@ -33,6 +33,22 @@ __RCSID("$NetBSD: h_gets.c,v 1.1 2010/12/27 02:04:19 pgoyette Exp $");
> 
> #include <stdio.h>
> 
>+#ifdef __FreeBSD__
>+/*
>+ * We want to test the gets() implementation, but cannot simply link against
>+ * the gets symbol because it is not in the default version. (We've made it
>+ * unavailable by default on FreeBSD because it should not be used.)
>+ *
>+ * This is a workaround to access gets@FBSD_1.0.
>+ */
>+char *unsafe_gets(char *);
>+char *gets(char *buf)
>+{
>+	return unsafe_gets(buf);
>+}
>+__sym_compat(gets, unsafe_gets, FBSD_1.0);
>+#endif
>+
> int
> main(int argc, char *argv[])
> {
>diff --git a/gnu/lib/libssp/Makefile b/gnu/lib/libssp/Makefile
>index e611f5dfee45..51e36d5ddb72 100644
>--- a/gnu/lib/libssp/Makefile
>+++ b/gnu/lib/libssp/Makefile
>@@ -17,7 +17,7 @@ LIB=		ssp
> SHLIB_MAJOR=	0
> LD_FATAL_WARNINGS=	no
> 
>-SRCS=	ssp.c gets-chk.c memcpy-chk.c memmove-chk.c mempcpy-chk.c \
>+SRCS=	ssp.c memcpy-chk.c memmove-chk.c mempcpy-chk.c \
> 	memset-chk.c snprintf-chk.c sprintf-chk.c stpcpy-chk.c \
> 	strcat-chk.c strcpy-chk.c strncat-chk.c strncpy-chk.c \
> 	vsnprintf-chk.c vsprintf-chk.c
>diff --git a/include/stdio.h b/include/stdio.h
>index e94583097a26..41ae893dd7db 100644
>--- a/include/stdio.h
>+++ b/include/stdio.h
>@@ -269,7 +269,6 @@ long	 ftell(FILE *);
> size_t	 fwrite(const void * __restrict, size_t, size_t, FILE * __restrict);
> int	 getc(FILE *);
> int	 getchar(void);
>-char	*gets(char *);
> #if __EXT1_VISIBLE
> char	*gets_s(char *, rsize_t);
> #endif
>diff --git a/lib/libc/stdio/fgets.3 b/lib/libc/stdio/fgets.3
>index ce334b7493b0..959a74a0f1df 100644
>--- a/lib/libc/stdio/fgets.3
>+++ b/lib/libc/stdio/fgets.3
>@@ -37,7 +37,6 @@
> .Os
> .Sh NAME
> .Nm fgets ,
>-.Nm gets ,
> .Nm gets_s
> .Nd get a line from a stream
> .Sh LIBRARY
>@@ -48,8 +47,6 @@
> .Fn fgets "char * restrict str" "int size" "FILE * restrict stream"
> .Ft char *
> .Fn gets_s "char *str" "rsize_t size"
>-.Ft char *
>-.Fn gets "char *str"
> .Sh DESCRIPTION
> The
> .Fn fgets
>@@ -81,23 +78,12 @@ except that the newline character (if any) is not stored in the string.
> The
> .Fn gets
> function
>-is equivalent to
>-.Fn fgets
>-with an infinite
>-.Fa size
>-and a
>-.Fa stream
>-of
>-.Dv stdin ,
>-except that the newline character (if any) is not stored in the string.
>-It is the caller's responsibility to ensure that the input line,
>-if any, is sufficiently short to fit in the string.
>+was unsafe and is no longer available.
> .Sh RETURN VALUES
> Upon successful completion,
>-.Fn fgets ,
>-.Fn gets_s ,
>+.Fn fgets
> and
>-.Fn gets
>+.Fn gets_s
> return
> a pointer to the string.
> If end-of-file occurs before any characters are read,
>@@ -109,10 +95,9 @@ they return
> .Dv NULL
> and the buffer contents are indeterminate.
> The
>-.Fn fgets ,
>-.Fn gets_s ,
>+.Fn fgets
> and
>-.Fn gets
>+.Fn gets_s
> functions
> do not distinguish between end-of-file and error, and callers must use
> .Xr feof 3
>@@ -139,8 +124,6 @@ or
> .Xr malloc 3 .
> .Pp
> The function
>-.Fn gets
>-and
> .Fn gets_s
> may also fail and set
> .Va errno
>@@ -153,11 +136,9 @@ for any of the errors specified for the routine
> .Xr fgetws 3 ,
> .Xr getline 3
> .Sh STANDARDS
>-The functions
>+The
> .Fn fgets
>-and
>-.Fn gets
>-conform to
>+function conforms to
> .St -isoC-99 .
> .Fn gets_s
> conforms to
>@@ -166,16 +147,3 @@ K.3.7.4.1.
> .Fn gets
> has been removed from
> .St -isoC-2011 .
>-.Sh SECURITY CONSIDERATIONS
>-The
>-.Fn gets
>-function cannot be used securely.
>-Because of its lack of bounds checking,
>-and the inability for the calling program
>-to reliably determine the length of the next incoming line,
>-the use of this function enables malicious users
>-to arbitrarily change a running program's functionality through
>-a buffer overflow attack.
>-It is strongly suggested that the
>-.Fn fgets
>-function be used in all cases.
>diff --git a/lib/libc/stdio/gets.c b/lib/libc/stdio/gets.c
>index 1f360ac5ae61..c8822e3b8d86 100644
>--- a/lib/libc/stdio/gets.c
>+++ b/lib/libc/stdio/gets.c
>@@ -45,10 +45,8 @@ __FBSDID("$FreeBSD$");
> #include "libc_private.h"
> #include "local.h"
> 
>-__warn_references(gets, "warning: this program uses gets(), which is unsafe.");
>-
> char *
>-gets(char *buf)
>+__gets_unsafe(char *buf)
> {
> 	int c;
> 	char *s, *ret;
>@@ -78,3 +76,4 @@ gets(char *buf)
> 	FUNLOCKFILE_CANCELSAFE();
> 	return (ret);
> }
>+__sym_compat(gets, __gets_unsafe, FBSD_1.0);
>diff --git a/lib/libc/stdio/stdio.3 b/lib/libc/stdio/stdio.3
>index 0ac315b957cb..7b3dd364c79a 100644
>--- a/lib/libc/stdio/stdio.3
>+++ b/lib/libc/stdio/stdio.3
>@@ -279,7 +279,6 @@ library conforms to
> .It "getchar	get next character or word from input stream"
> .It "getdelim	get a line from a stream"
> .It "getline	get a line from a stream"
>-.It "gets	get a line from a stream"
> .It "getw	get next character or word from input stream"
> .It "getwc	get next wide character from input stream"
> .It "getwchar	get next wide character from input stream"

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Attachments on bug 222796: 186922 | 186923 | 198620 | 198688