diff options
| author | rillig <rillig@NetBSD.org> | 2020-12-22 08:05:08 +0000 |
|---|---|---|
| committer | rillig <rillig@NetBSD.org> | 2020-12-22 08:05:08 +0000 |
| commit | 9e661d02a56e5753fb2ea74c0f79351cacf361ea (patch) | |
| tree | 0fc649e1b678e89d97bdd5432fe9d5a4493dea54 /usr.bin/make/parse.c | |
| parent | 43d2fe8635ba903eaa5f910358b6bac77192de43 (diff) | |
make(1): fix assertion failure for files without trailing newline
Previously, mmapped files didn't always have the final newline added.
Only those that ended at a page boundary did.
This confused ParseRawLine, which assumed (and since parse.c 1.510 from
moments ago also asserted) that every line ends with a newline, which
allows the code to assume that after a backslash, there is at least one
other character in the buffer, thereby preventing an out-of-bounds read.
This bug had been there at least since parse.c 1.170 from 2010-12-25
04:57:07, maybe even earlier, I didn't check.
Now line_end always points to the trailing newline, which allows
ParseGetLine to overwrite that character to end the string.
Diffstat (limited to 'usr.bin/make/parse.c')
| -rw-r--r-- | usr.bin/make/parse.c | 47 |
1 files changed, 20 insertions, 27 deletions
diff --git a/usr.bin/make/parse.c b/usr.bin/make/parse.c index db6fca0f002..c4751531743 100644 --- a/usr.bin/make/parse.c +++ b/usr.bin/make/parse.c @@ -1,4 +1,4 @@ -/* $NetBSD: parse.c,v 1.510 2020/12/22 06:48:33 rillig Exp $ */ +/* $NetBSD: parse.c,v 1.511 2020/12/22 08:05:08 rillig Exp $ */ /* * Copyright (c) 1988, 1989, 1990, 1993 @@ -117,7 +117,7 @@ #include "pathnames.h" /* "@(#)parse.c 8.3 (Berkeley) 3/19/94" */ -MAKE_RCSID("$NetBSD: parse.c,v 1.510 2020/12/22 06:48:33 rillig Exp $"); +MAKE_RCSID("$NetBSD: parse.c,v 1.511 2020/12/22 08:05:08 rillig Exp $"); /* types and constants */ @@ -466,13 +466,14 @@ loadedfile_mmap(struct loadedfile *lf, int fd) if (lf->buf == MAP_FAILED) return FALSE; - if (lf->len == lf->maplen && lf->buf[lf->len - 1] != '\n') { - char *b = bmake_malloc(lf->len + 1); - b[lf->len] = '\n'; - memcpy(b, lf->buf, lf->len++); - munmap(lf->buf, lf->maplen); - lf->maplen = 0; - lf->buf = b; + if (lf->len > 0 && lf->buf[lf->len - 1] != '\n') { + if (lf->len == lf->maplen) { + char *b = bmake_malloc(lf->len + 1); + memcpy(b, lf->buf, lf->len); + munmap(lf->buf, lf->maplen); + lf->maplen = 0; + } + lf->buf[lf->len++] = '\n'; } return TRUE; @@ -2687,19 +2688,15 @@ ParseRawLine(IFile *curFile, char **out_line, char **out_line_end, if (ch == '\\') { if (firstBackslash == NULL) firstBackslash = p; - /* - * FIXME: In opt-file.mk, this command succeeds: - * printf '%s' 'V=v\' | make -r -f - - * Using an intermediate file fails though: - * printf '%s' 'V=v\' > backslash - * make -r -f backslash - * - * In loadedfile_mmap, the trailing newline is not - * added in every case, only if the file ends at a - * page boundary. - */ - if (p[1] == '\n') + if (p[1] == '\n') { curFile->lineno++; + if (p + 2 == curFile->buf_end) { + line_end = p; + *line_end = '\n'; + p += 2; + continue; + } + } p += 2; line_end = p; assert(p <= curFile->buf_end); @@ -2843,12 +2840,8 @@ ParseGetLine(GetLineMode mode) } /* We now have a line of data */ - /* - * FIXME: undefined behavior since line_end points right - * after the allocated buffer. This becomes apparent when - * using a strict malloc implementation that adds canaries - * before and after the allocated space. - */ + /* TODO: Remove line_end, it's not necessary here. */ + assert(*line_end == '\n'); *line_end = '\0'; if (mode == GLM_FOR_BODY) |
