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 --- cache.h | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) (limited to 'cache.h') diff --git a/cache.h b/cache.h index 4a054c540..9eaffdefd 100644 --- a/cache.h +++ b/cache.h @@ -131,8 +131,21 @@ struct cache_entry { #define CE_UPDATE (0x10000) #define CE_REMOVE (0x20000) -#define create_ce_flags(len, stage) ((len) | ((stage) << CE_STAGESHIFT)) -#define ce_namelen(ce) (CE_NAMEMASK & (ce)->ce_flags) +static inline unsigned create_ce_flags(size_t len, unsigned stage) +{ + if (len >= CE_NAMEMASK) + len = CE_NAMEMASK; + return (len | (stage << CE_STAGESHIFT)); +} + +static inline size_t ce_namelen(const struct cache_entry *ce) +{ + size_t len = ce->ce_flags & CE_NAMEMASK; + if (len < CE_NAMEMASK) + return len; + return strlen(ce->name + CE_NAMEMASK) + CE_NAMEMASK; +} + #define ce_size(ce) cache_entry_size(ce_namelen(ce)) #define ondisk_ce_size(ce) ondisk_cache_entry_size(ce_namelen(ce)) #define ce_stage(ce) ((CE_STAGEMASK & (ce)->ce_flags) >> CE_STAGESHIFT) -- cgit v1.2.1