Revision 447ac906e189535e77dcb1f4bbe3f1bc917d4c12 authored by Patrick Steinhardt on 01 December 2022, 14:45:31 UTC, committed by Junio C Hamano on 05 December 2022, 06:14:16 UTC
The `struct attr_stack` tracks the stack of all patterns together with their attributes. When parsing a gitattributes file that has more than 2^31 such patterns though we may trigger multiple out-of-bounds reads on 64 bit platforms. This is because while the `num_matches` variable is an unsigned integer, we always use a signed integer to iterate over them. I have not been able to reproduce this issue due to memory constraints on my systems. But despite the out-of-bounds reads, the worst thing that can seemingly happen is to call free(3P) with a garbage pointer when calling `attr_stack_free()`. Fix this bug by using unsigned integers to iterate over the array. While this makes the iteration somewhat awkward when iterating in reverse, it is at least better than knowingly running into an out-of-bounds read. While at it, convert the call to `ALLOC_GROW` to use `ALLOC_GROW_BY` instead. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 34ace8b
merge.c
#include "cache.h"
#include "diff.h"
#include "diffcore.h"
#include "lockfile.h"
#include "commit.h"
#include "run-command.h"
#include "resolve-undo.h"
#include "tree-walk.h"
#include "unpack-trees.h"
#include "dir.h"
static const char *merge_argument(struct commit *commit)
{
return oid_to_hex(commit ? &commit->object.oid : the_hash_algo->empty_tree);
}
int try_merge_command(struct repository *r,
const char *strategy, size_t xopts_nr,
const char **xopts, struct commit_list *common,
const char *head_arg, struct commit_list *remotes)
{
struct strvec args = STRVEC_INIT;
int i, ret;
struct commit_list *j;
strvec_pushf(&args, "merge-%s", strategy);
for (i = 0; i < xopts_nr; i++)
strvec_pushf(&args, "--%s", xopts[i]);
for (j = common; j; j = j->next)
strvec_push(&args, merge_argument(j->item));
strvec_push(&args, "--");
strvec_push(&args, head_arg);
for (j = remotes; j; j = j->next)
strvec_push(&args, merge_argument(j->item));
ret = run_command_v_opt(args.v, RUN_GIT_CMD);
strvec_clear(&args);
discard_index(r->index);
if (repo_read_index(r) < 0)
die(_("failed to read the cache"));
resolve_undo_clear_index(r->index);
return ret;
}
int checkout_fast_forward(struct repository *r,
const struct object_id *head,
const struct object_id *remote,
int overwrite_ignore)
{
struct tree *trees[MAX_UNPACK_TREES];
struct unpack_trees_options opts;
struct tree_desc t[MAX_UNPACK_TREES];
int i, nr_trees = 0;
struct dir_struct dir;
struct lock_file lock_file = LOCK_INIT;
refresh_index(r->index, REFRESH_QUIET, NULL, NULL, NULL);
if (repo_hold_locked_index(r, &lock_file, LOCK_REPORT_ON_ERROR) < 0)
return -1;
memset(&trees, 0, sizeof(trees));
memset(&t, 0, sizeof(t));
trees[nr_trees] = parse_tree_indirect(head);
if (!trees[nr_trees++]) {
rollback_lock_file(&lock_file);
return -1;
}
trees[nr_trees] = parse_tree_indirect(remote);
if (!trees[nr_trees++]) {
rollback_lock_file(&lock_file);
return -1;
}
for (i = 0; i < nr_trees; i++) {
parse_tree(trees[i]);
init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
}
memset(&opts, 0, sizeof(opts));
dir_init(&dir);
if (overwrite_ignore) {
dir.flags |= DIR_SHOW_IGNORED;
setup_standard_excludes(&dir);
opts.dir = &dir;
}
opts.head_idx = 1;
opts.src_index = r->index;
opts.dst_index = r->index;
opts.update = 1;
opts.verbose_update = 1;
opts.merge = 1;
opts.fn = twoway_merge;
init_checkout_metadata(&opts.meta, NULL, remote, NULL);
setup_unpack_trees_porcelain(&opts, "merge");
if (unpack_trees(nr_trees, t, &opts)) {
rollback_lock_file(&lock_file);
clear_unpack_trees_porcelain(&opts);
return -1;
}
dir_clear(&dir);
clear_unpack_trees_porcelain(&opts);
if (write_locked_index(r->index, &lock_file, COMMIT_LOCK))
return error(_("unable to write new index file"));
return 0;
}
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