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Fix mmap leak caused by reading bad indexes.

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If an index is corrupt, or is simply too new for us to understand,
we were leaking the mmap that held the entire content of the index.
This could be a considerable size on large projects, given that
the index is at least 24 bytes * nr_objects.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This commit is contained in:
Shawn O. Pearce 2007-03-06 20:44:11 -05:00 committed by Junio C Hamano
parent 30fee0625d
commit 2d88451b7a
1 changed files with 16 additions and 9 deletions
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25
sha1_file.c
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@ -430,8 +430,9 @@ void pack_report()
pack_mapped, peak_pack_mapped);
}
static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
void **idx_map_)
static int check_packed_git_idx(const char *path,
unsigned long *idx_size_,
void **idx_map_)
{
void *idx_map;
uint32_t *index;
@ -446,6 +447,10 @@ static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
return -1;
}
idx_size = st.st_size;
if (idx_size < 4 * 256 + 20 + 20) {
close(fd);
return error("index file %s is too small", path);
}
idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
@ -453,25 +458,25 @@ static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
*idx_map_ = idx_map;
*idx_size_ = idx_size;
/* check index map */
if (idx_size < 4*256 + 20 + 20)
return error("index file %s is too small", path);
/* a future index format would start with this, as older git
* binaries would fail the non-monotonic index check below.
* give a nicer warning to the user if we can.
*/
if (index[0] == htonl(PACK_IDX_SIGNATURE))
if (index[0] == htonl(PACK_IDX_SIGNATURE)) {
munmap(idx_map, idx_size);
return error("index file %s is a newer version"
" and is not supported by this binary"
" (try upgrading GIT to a newer version)",
path);
}
nr = 0;
for (i = 0; i < 256; i++) {
unsigned int n = ntohl(index[i]);
if (n < nr)
if (n < nr) {
munmap(idx_map, idx_size);
return error("non-monotonic index %s", path);
}
nr = n;
}
@ -482,8 +487,10 @@ static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
* - 20-byte SHA1 of the packfile
* - 20-byte SHA1 file checksum
*/
if (idx_size != 4*256 + nr * 24 + 20 + 20)
if (idx_size != 4*256 + nr * 24 + 20 + 20) {
munmap(idx_map, idx_size);
return error("wrong index file size in %s", path);
}
return 0;
}