exec: restore EACCES of S_ISDIR execve()

Patch series "Fix S_ISDIR execve() errno". Fix an errno change for execve() of directories, noticed by Marc Zyngier. Along with the fix, include a regression test to avoid seeing this return in the future. This patch (of 2): The return code for attempting to execute a directory has always been EACCES. Adjust the S_ISDIR exec test to reflect the old errno instead of the general EISDIR for other kinds of "open" attempts on directories. Fixes: 633fb6a ("exec: move S_ISREG() check earlier") Reported-by: Marc Zyngier <[email protected]> Signed-off-by: Kees Cook <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Tested-by: Greg Kroah-Hartman <[email protected]> Reviewed-by: Greg Kroah-Hartman <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Link: https://lore.kernel.org/lkml/20200813151305.6191993b@why Signed-off-by: Linus Torvalds <[email protected]>
tadfisher · Aug 15, 2020 · fc4177b · fc4177b
1 parent b1a3e75
commit fc4177b
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/fs/namei.c b/fs/namei.c
@@ -2849,8 +2849,10 @@ static int may_open(const struct path *path, int acc_mode, int flag)
 	case S_IFLNK:
 		return -ELOOP;
 	case S_IFDIR:
-		if (acc_mode & (MAY_WRITE | MAY_EXEC))
+		if (acc_mode & MAY_WRITE)
 			return -EISDIR;
+		if (acc_mode & MAY_EXEC)
+			return -EACCES;
 		break;
 	case S_IFBLK:
 	case S_IFCHR: