diff options
| -rw-r--r-- | cache.h | 2 | ||||
| -rw-r--r-- | sha1_file.c | 92 |
2 files changed, 78 insertions, 16 deletions
@@ -641,6 +641,8 @@ extern struct packed_git { const void *index_data; size_t index_size; uint32_t num_objects; + uint32_t num_bad_objects; + unsigned char *bad_object_sha1; int index_version; time_t mtime; int pack_fd; diff --git a/sha1_file.c b/sha1_file.c index 92299ed62..9330bc492 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -818,6 +818,8 @@ struct packed_git *add_packed_git(const char *path, int path_len, int local) p->index_data = NULL; p->index_size = 0; p->num_objects = 0; + p->num_bad_objects = 0; + p->bad_object_sha1 = NULL; p->pack_size = st.st_size; p->next = NULL; p->windows = NULL; @@ -982,6 +984,18 @@ void reprepare_packed_git(void) prepare_packed_git(); } +static void mark_bad_packed_object(struct packed_git *p, + const unsigned char *sha1) +{ + unsigned i; + for (i = 0; i < p->num_bad_objects; i++) + if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i)) + return; + p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1)); + hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1); + p->num_bad_objects++; +} + int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type) { unsigned char real_sha1[20]; @@ -1300,20 +1314,17 @@ static off_t get_delta_base(struct packed_git *p, while (c & 128) { base_offset += 1; if (!base_offset || MSB(base_offset, 7)) - die("offset value overflow for delta base object"); + return 0; /* overflow */ c = base_info[used++]; base_offset = (base_offset << 7) + (c & 127); } base_offset = delta_obj_offset - base_offset; if (base_offset >= delta_obj_offset) - die("delta base offset out of bound"); + return 0; /* out of bound */ *curpos += used; } else if (type == OBJ_REF_DELTA) { /* The base entry _must_ be in the same pack */ base_offset = find_pack_entry_one(base_info, p); - if (!base_offset) - die("failed to find delta-pack base object %s", - sha1_to_hex(base_info)); *curpos += 20; } else die("I am totally screwed"); @@ -1406,6 +1417,9 @@ const char *packed_object_info_detail(struct packed_git *p, return typename(type); case OBJ_OFS_DELTA: obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset); + if (!obj_offset) + die("pack %s contains bad delta base reference of type %s", + p->pack_name, typename(type)); if (*delta_chain_length == 0) { revidx = find_pack_revindex(p, obj_offset); hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr)); @@ -1600,17 +1614,41 @@ static void *unpack_delta_entry(struct packed_git *p, off_t base_offset; base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset); + if (!base_offset) { + error("failed to validate delta base reference " + "at offset %"PRIuMAX" from %s", + (uintmax_t)curpos, p->pack_name); + return NULL; + } base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0); - if (!base) - die("failed to read delta base object" - " at %"PRIuMAX" from %s", - (uintmax_t)base_offset, p->pack_name); + if (!base) { + /* + * We're probably in deep shit, but let's try to fetch + * the required base anyway from another pack or loose. + * This is costly but should happen only in the presence + * of a corrupted pack, and is better than failing outright. + */ + struct revindex_entry *revidx = find_pack_revindex(p, base_offset); + const unsigned char *base_sha1 = + nth_packed_object_sha1(p, revidx->nr); + error("failed to read delta base object %s" + " at offset %"PRIuMAX" from %s", + sha1_to_hex(base_sha1), (uintmax_t)base_offset, + p->pack_name); + mark_bad_packed_object(p, base_sha1); + base = read_sha1_file(base_sha1, type, &base_size); + if (!base) + return NULL; + } delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size); - if (!delta_data) - die("failed to unpack compressed delta" - " at %"PRIuMAX" from %s", - (uintmax_t)curpos, p->pack_name); + if (!delta_data) { + error("failed to unpack compressed delta " + "at offset %"PRIuMAX" from %s", + (uintmax_t)curpos, p->pack_name); + free(base); + return NULL; + } result = patch_delta(base, base_size, delta_data, delta_size, sizep); @@ -1642,7 +1680,9 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset, data = unpack_compressed_entry(p, &w_curs, curpos, *sizep); break; default: - die("unknown object type %i in %s", *type, p->pack_name); + data = NULL; + error("unknown object type %i at offset %"PRIuMAX" in %s", + *type, (uintmax_t)obj_offset, p->pack_name); } unuse_pack(&w_curs); return data; @@ -1788,6 +1828,13 @@ static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, cons goto next; } + if (p->num_bad_objects) { + unsigned i; + for (i = 0; i < p->num_bad_objects; i++) + if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i)) + goto next; + } + offset = find_pack_entry_one(sha1, p); if (offset) { /* @@ -1872,11 +1919,24 @@ static void *read_packed_sha1(const unsigned char *sha1, enum object_type *type, unsigned long *size) { struct pack_entry e; + void *data; if (!find_pack_entry(sha1, &e, NULL)) return NULL; - else - return cache_or_unpack_entry(e.p, e.offset, size, type, 1); + data = cache_or_unpack_entry(e.p, e.offset, size, type, 1); + if (!data) { + /* + * We're probably in deep shit, but let's try to fetch + * the required object anyway from another pack or loose. + * This should happen only in the presence of a corrupted + * pack, and is better than failing outright. + */ + error("failed to read object %s at offset %"PRIuMAX" from %s", + sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name); + mark_bad_packed_object(e.p, sha1); + data = read_sha1_file(sha1, type, size); + } + return data; } /* |