Re: "malloc failed"
From: David Abrahams <hidden>
Date: 2016-06-15 22:46:03
on Thu Jan 29 2009, Jeff King <peff-AT-peff.net> wrote:
On Thu, Jan 29, 2009 at 12:20:41AM -0500, Jeff King wrote:quoted
Ok, that _is_ big. ;) I wouldn't be surprised if there is some corner of the code that barfs on a single object that doesn't fit in a signed 32-bit integer; I don't think we have any test coverage for stuff that big.Sure enough, that is the problem. With the patch below I was able to "git add" and commit a 3 gigabyte file of random bytes (so even the deflated object was 3G). I think it might be worth applying as a general cleanup, but I have no idea if other parts of the system might barf on such an object. -- >8 -- Subject: [PATCH] avoid 31-bit truncation in write_loose_object The size of the content we are adding may be larger than 2.1G (i.e., "git add gigantic-file"). Most of the code-path to do so uses size_t or unsigned long to record the size, but write_loose_object uses a signed int. On platforms where "int" is 32-bits (which includes x86_64 Linux platforms), we end up passing malloc a negative size.
Good work. I don't know if this matters to you, but I think on a 32-bit
platform you'll find that size_t, which is supposed to be able to hold
the size of the largest representable *memory block*, is only 4 bytes
large:
#include <limits.h>
#include <stdio.h>
int main()
{
printf("sizeof(size_t) = %d", sizeof(size_t));
}
Prints "sizeof(size_t) = 4" on my core duo.
quoted hunk
Signed-off-by: Jeff King <redacted> --- sha1_file.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)diff --git a/sha1_file.c b/sha1_file.c index 360f7e5..8868b80 100644 --- a/sha1_file.c +++ b/sha1_file.c@@ -2340,7 +2340,8 @@ static int create_tmpfile(char *buffer, size_t bufsiz, constchar *filename) static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen, void *buf, unsigned long len, time_t mtime) { - int fd, size, ret; + int fd, ret; + size_t size; unsigned char *compressed; z_stream stream; char *filename;
-- Dave Abrahams BoostPro Computing http://www.boostpro.com