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-rw-r--r--util.c60
1 files changed, 30 insertions, 30 deletions
diff --git a/util.c b/util.c
index 0aafcb1..eeffdae 100644
--- a/util.c
+++ b/util.c
@@ -2,7 +2,7 @@
* Common "util" functions
* This file is part of the dmidecode project.
*
- * Copyright (C) 2002-2017 Jean Delvare <jdelvare@suse.de>
+ * Copyright (C) 2002-2018 Jean Delvare <jdelvare@suse.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -59,7 +59,6 @@ static int myread(int fd, u8 *buf, size_t count, const char *prefix)
{
if (errno != EINTR)
{
- close(fd);
perror(prefix);
return -1;
}
@@ -70,7 +69,6 @@ static int myread(int fd, u8 *buf, size_t count, const char *prefix)
if (r2 != count)
{
- close(fd);
fprintf(stderr, "%s: Unexpected end of file\n", prefix);
return -1;
}
@@ -90,19 +88,17 @@ int checksum(const u8 *buf, size_t len)
/*
* Reads all of file from given offset, up to max_len bytes.
- * A buffer of max_len bytes is allocated by this function, and
+ * A buffer of at most max_len bytes is allocated by this function, and
* needs to be freed by the caller.
* This provides a similar usage model to mem_chunk()
*
- * Returns pointer to buffer of max_len bytes, or NULL on error, and
+ * Returns a pointer to the allocated buffer, or NULL on error, and
* sets max_len to the length actually read.
- *
*/
void *read_file(off_t base, size_t *max_len, const char *filename)
{
+ struct stat statbuf;
int fd;
- size_t r2 = 0;
- ssize_t r;
u8 *p;
/*
@@ -116,12 +112,20 @@ void *read_file(off_t base, size_t *max_len, const char *filename)
return NULL;
}
- if (lseek(fd, base, SEEK_SET) == -1)
+ /*
+ * Check file size, don't allocate more than can be read.
+ */
+ if (fstat(fd, &statbuf) == 0)
{
- fprintf(stderr, "%s: ", filename);
- perror("lseek");
- p = NULL;
- goto out;
+ if (base >= statbuf.st_size)
+ {
+ fprintf(stderr, "%s: Can't read data beyond EOF\n",
+ filename);
+ p = NULL;
+ goto out;
+ }
+ if (*max_len > (size_t)statbuf.st_size - base)
+ *max_len = statbuf.st_size - base;
}
if ((p = malloc(*max_len)) == NULL)
@@ -130,27 +134,23 @@ void *read_file(off_t base, size_t *max_len, const char *filename)
goto out;
}
- do
+ if (lseek(fd, base, SEEK_SET) == -1)
{
- r = read(fd, p + r2, *max_len - r2);
- if (r == -1)
- {
- if (errno != EINTR)
- {
- perror(filename);
- free(p);
- p = NULL;
- goto out;
- }
- }
- else
- r2 += r;
+ fprintf(stderr, "%s: ", filename);
+ perror("lseek");
+ goto err_free;
}
- while (r != 0);
- *max_len = r2;
+ if (myread(fd, p, *max_len, filename) == 0)
+ goto out;
+
+err_free:
+ free(p);
+ p = NULL;
+
out:
- close(fd);
+ if (close(fd) == -1)
+ perror(filename);
return p;
}