mailmap: avoid out-of-bounds memory access

diff --git a/read-cache.c b/read-cache.c
index 2f8159fb165f853aafb5e0cee61f35aa854271ec..79e3bbe0240e16629e8ba4b755d60f986132802a 100644 (file)
--- a/read-cache.c
+++ b/read-cache.c
@@ -1414,11 +1414,9 @@ int read_index_from(struct index_state *istate, const char *path)
        size_t mmap_size;
        struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
 
-       errno = EBUSY;
        if (istate->initialized)
                return istate->cache_nr;
 
-       errno = ENOENT;
        istate->timestamp.sec = 0;
        istate->timestamp.nsec = 0;
        fd = open(path, O_RDONLY);
@@ -1431,15 +1429,14 @@ int read_index_from(struct index_state *istate, const char *path)
        if (fstat(fd, &st))
                die_errno("cannot stat the open index");
 
-       errno = EINVAL;
        mmap_size = xsize_t(st.st_size);
        if (mmap_size < sizeof(struct cache_header) + 20)
                die("index file smaller than expected");
 
        mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
-       close(fd);
        if (mmap == MAP_FAILED)
                die_errno("unable to map index file");
+       close(fd);
 
        hdr = mmap;
        if (verify_hdr(hdr, mmap_size) < 0)
@@ -1495,7 +1492,6 @@ int read_index_from(struct index_state *istate, const char *path)
 
 unmap:
        munmap(mmap, mmap_size);
-       errno = EINVAL;
        die("index file corrupt");
 }
 
@@ -1800,6 +1796,8 @@ int write_index(struct index_state *istate, int newfd)
                        continue;
                if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
                        ce_smudge_racily_clean_entry(ce);
+               if (is_null_sha1(ce->sha1))
+                       return error("cache entry has null sha1: %s", ce->name);
                if (ce_write_entry(&c, newfd, ce, previous_name) < 0)
                        return -1;
        }