limit maildir nesting depth

this is a cheap way to catch symlink loops. 10 seems like a reasonable
limit, as it's unlikely that anyone would be able to actually work with
such a deeply nested mailbox tree.

fixes debian bug #990117.
This commit is contained in:
Oswald Buddenhagen 2021-06-21 11:35:24 +02:00
parent a846ab054d
commit 7979782676

View File

@ -395,7 +395,7 @@ static int maildir_list_inbox( maildir_store_t *ctx, int flags, const char *base
static int maildir_list_path( maildir_store_t *ctx, int flags, const char *inbox );
static int
maildir_list_recurse( maildir_store_t *ctx, int isBox, int flags,
maildir_list_recurse( maildir_store_t *ctx, int isBox, int flags, int depth,
const char *inbox, uint inboxLen, const char *basePath, uint basePathLen,
char *path, int pathLen, char *name, int nameLen )
{
@ -417,6 +417,12 @@ maildir_list_recurse( maildir_store_t *ctx, int isBox, int flags,
closedir( dir );
return -1;
}
if (++depth > 10) {
// We do the other checks first to avoid confusing error messages for files.
error( "Maildir error: path %s is too deeply nested. Symlink loop?\n", path );
closedir( dir );
return -1;
}
while ((de = readdir( dir ))) {
const char *ent = de->d_name;
if (ent[0] == '.' && (!ent[1] || (ent[1] == '.' && !ent[2])))
@ -464,7 +470,7 @@ maildir_list_recurse( maildir_store_t *ctx, int isBox, int flags,
add_string_list( &ctx->boxes, name );
path[pl] = 0;
name[nl++] = '/';
if (maildir_list_recurse( ctx, isBox + 1, flags, inbox, inboxLen, basePath, basePathLen, path, pl, name, nl ) < 0) {
if (maildir_list_recurse( ctx, isBox + 1, flags, depth, inbox, inboxLen, basePath, basePathLen, path, pl, name, nl ) < 0) {
closedir( dir );
return -1;
}
@ -485,7 +491,7 @@ maildir_list_inbox( maildir_store_t *ctx, int flags, const char *basePath )
add_string_list( &ctx->boxes, "INBOX" );
return maildir_list_recurse(
ctx, 1, flags, NULL, 0, basePath, basePath ? strlen( basePath ) - 1 : 0,
ctx, 1, flags, 0, NULL, 0, basePath, basePath ? strlen( basePath ) - 1 : 0,
path, nfsnprintf( path, _POSIX_PATH_MAX, "%s/", ctx->conf->inbox ),
name, nfsnprintf( name, _POSIX_PATH_MAX, "INBOX/" ) );
}
@ -502,7 +508,7 @@ maildir_list_path( maildir_store_t *ctx, int flags, const char *inbox )
if (maildir_ensure_path( ctx->conf ) < 0)
return -1;
return maildir_list_recurse(
ctx, 0, flags, inbox, inbox ? strlen( inbox ) : 0, NULL, 0,
ctx, 0, flags, 0, inbox, inbox ? strlen( inbox ) : 0, NULL, 0,
path, nfsnprintf( path, _POSIX_PATH_MAX, "%s", ctx->conf->path ),
name, 0 );
}