find: In -execdir ... {} +, only pass one file per invocation.

This is inefficient but ensures that -execdir ... {} + does not mix files
from different directories in one invocation; the command could not access
some files. Files from the same directory should really be handled in one
invocation but this is somewhat more complicated.

1 files changed, 7 insertions, 1 deletions

diff --git a/usr.bin/find/function.c b/usr.bin/find/function.c
index 5f8f8130432d..4f2eba7433f2 100644
--- a/usr.bin/find/function.c
+++ b/usr.bin/find/function.c
@@ -711,7 +711,13 @@ c_exec(OPTION *option, char ***argvp)
 		for (ep = environ; *ep != NULL; ep++)
 			argmax -= strlen(*ep) + 1 + sizeof(*ep);
 		argmax -= 1 + sizeof(*ep);
-		new->e_pnummax = argmax / 16;
+		/*
+		 * Ensure that -execdir ... {} + does not mix files
+		 * from different directories in one invocation.
+		 * Files from the same directory should be handled
+		 * in one invocation but there is no code for it.
+		 */
+		new->e_pnummax = new->flags & F_EXECDIR ? 1 : argmax / 16;
 		argmax -= sizeof(char *) * new->e_pnummax;
 		if (argmax <= 0)
 			errx(1, "no space for arguments");