From d7dd02231f75604e388afb905f7bf8afd1bf4b24 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Mon, 9 Apr 2007 01:06:30 -0400 Subject: [PATCH] add overflow tests on pack offset variables Change a few size and offset variables to more appropriate type, then add overflow tests on those offsets. This prevents any bad data to be generated/processed if off_t happens to not be large enough to handle some big packs. Better be safe than sorry. Signed-off-by: Nicolas Pitre Signed-off-by: Junio C Hamano --- builtin-pack-objects.c | 19 +++++++++++++------ builtin-unpack-objects.c | 17 +++++++++++------ index-pack.c | 14 ++++++++++---- 3 files changed, 34 insertions(+), 16 deletions(-) diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c index ee607a0d2..d0be87944 100644 --- a/builtin-pack-objects.c +++ b/builtin-pack-objects.c @@ -369,7 +369,7 @@ static int revalidate_loose_object(struct object_entry *entry, return check_loose_inflate(map, mapsize, size); } -static off_t write_object(struct sha1file *f, +static unsigned long write_object(struct sha1file *f, struct object_entry *entry) { unsigned long size; @@ -503,16 +503,23 @@ static off_t write_one(struct sha1file *f, struct object_entry *e, off_t offset) { + unsigned long size; + + /* offset is non zero if object is written already. */ if (e->offset || e->preferred_base) - /* offset starts from header size and cannot be zero - * if it is written already. - */ return offset; - /* if we are deltified, write out its base object first. */ + + /* if we are deltified, write out base object first. */ if (e->delta) offset = write_one(f, e->delta, offset); + e->offset = offset; - return offset + write_object(f, e); + size = write_object(f, e); + + /* make sure off_t is sufficiently large not to wrap */ + if (offset > offset + size) + die("pack too large for current definition of off_t"); + return offset + size; } static void write_pack_file(void) diff --git a/builtin-unpack-objects.c b/builtin-unpack-objects.c index 63f7db683..f82190646 100644 --- a/builtin-unpack-objects.c +++ b/builtin-unpack-objects.c @@ -13,7 +13,8 @@ static const char unpack_usage[] = "git-unpack-objects [-n] [-q] [-r] < pack-fil /* We always read in 4kB chunks. */ static unsigned char buffer[4096]; -static unsigned long offset, len, consumed_bytes; +static unsigned int offset, len; +static off_t consumed_bytes; static SHA_CTX ctx; /* @@ -49,6 +50,10 @@ static void use(int bytes) die("used more bytes than were available"); len -= bytes; offset += bytes; + + /* make sure off_t is sufficiently large not to wrap */ + if (consumed_bytes > consumed_bytes + bytes) + die("pack too large for current definition of off_t"); consumed_bytes += bytes; } @@ -88,17 +93,17 @@ static void *get_data(unsigned long size) struct delta_info { unsigned char base_sha1[20]; - unsigned long base_offset; + unsigned nr; + off_t base_offset; unsigned long size; void *delta; - unsigned nr; struct delta_info *next; }; static struct delta_info *delta_list; static void add_delta_to_list(unsigned nr, unsigned const char *base_sha1, - unsigned long base_offset, + off_t base_offset, void *delta, unsigned long size) { struct delta_info *info = xmalloc(sizeof(*info)); @@ -113,7 +118,7 @@ static void add_delta_to_list(unsigned nr, unsigned const char *base_sha1, } struct obj_info { - unsigned long offset; + off_t offset; unsigned char sha1[20]; }; @@ -200,7 +205,7 @@ static void unpack_delta_entry(enum object_type type, unsigned long delta_size, } else { unsigned base_found = 0; unsigned char *pack, c; - unsigned long base_offset; + off_t base_offset; unsigned lo, mid, hi; pack = fill(1); diff --git a/index-pack.c b/index-pack.c index 0e54aa684..66fb0bced 100644 --- a/index-pack.c +++ b/index-pack.c @@ -12,7 +12,7 @@ static const char index_pack_usage[] = struct object_entry { - unsigned long offset; + off_t offset; unsigned long size; unsigned int hdr_size; enum object_type type; @@ -22,7 +22,7 @@ struct object_entry union delta_base { unsigned char sha1[20]; - unsigned long offset; + off_t offset; }; /* @@ -83,7 +83,8 @@ static unsigned display_progress(unsigned n, unsigned total, unsigned last_pc) /* We always read in 4kB chunks. */ static unsigned char input_buffer[4096]; -static unsigned long input_offset, input_len, consumed_bytes; +static unsigned int input_offset, input_len; +static off_t consumed_bytes; static SHA_CTX input_ctx; static int input_fd, output_fd, pack_fd; @@ -129,6 +130,10 @@ static void use(int bytes) die("used more bytes than were available"); input_len -= bytes; input_offset += bytes; + + /* make sure off_t is sufficiently large not to wrap */ + if (consumed_bytes > consumed_bytes + bytes) + die("pack too large for current definition of off_t"); consumed_bytes += bytes; } @@ -216,7 +221,8 @@ static void *unpack_entry_data(unsigned long offset, unsigned long size) static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base) { unsigned char *p, c; - unsigned long size, base_offset; + unsigned long size; + off_t base_offset; unsigned shift; obj->offset = consumed_bytes; -- 2.26.2