From 7fec10b7f41fa32e71aa6377bd04cd7c6fb419e0 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Fri, 18 Jan 2008 23:42:00 -0800 Subject: index: be careful when handling long names We currently use lower 12-bit (masked with CE_NAMEMASK) in the ce_flags field to store the length of the name in cache_entry, without checking the length parameter given to create_ce_flags(). This can make us store incorrect length. Currently we are mostly protected by the fact that many codepaths first copy the path in a variable of size PATH_MAX, which typically is 4096 that happens to match the limit, but that feels like a bug waiting to happen. Besides, that would not allow us to shorten the width of CE_NAMEMASK to use the bits for new flags. This redefines the meaning of the name length stored in the cache_entry. A name that does not fit is represented by storing CE_NAMEMASK in the field, and the actual length needs to be computed by actually counting the bytes in the name[] field. This way, only the unusually long paths need to suffer. Signed-off-by: Junio C Hamano Signed-off-by: Linus Torvalds --- read-cache.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'read-cache.c') diff --git a/read-cache.c b/read-cache.c index 82a6238b77..528f697f59 100644 --- a/read-cache.c +++ b/read-cache.c @@ -928,6 +928,8 @@ int read_index(struct index_state *istate) static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce) { + size_t len; + ce->ce_ctime = ntohl(ondisk->ctime.sec); ce->ce_mtime = ntohl(ondisk->mtime.sec); ce->ce_dev = ntohl(ondisk->dev); @@ -939,7 +941,15 @@ static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_en /* On-disk flags are just 16 bits */ ce->ce_flags = ntohs(ondisk->flags); hashcpy(ce->sha1, ondisk->sha1); - memcpy(ce->name, ondisk->name, ce_namelen(ce)+1); + + len = ce->ce_flags & CE_NAMEMASK; + if (len == CE_NAMEMASK) + len = strlen(ondisk->name); + /* + * NEEDSWORK: If the original index is crafted, this copy could + * go unchecked. + */ + memcpy(ce->name, ondisk->name, len + 1); } /* remember to discard_cache() before reading a different cache! */ -- cgit v1.3