[PATCH 3/9] fs: explicitly check for CHECK_IOVEC_ONLY in rw_copy_check_uvector

Christoph Hellwig hch at lst.de
Fri Sep 18 12:45:27 UTC 2020


Explicitly check for the magic value insted of implicitly relying on
its number representation.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 fs/read_write.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index 5db58b8c78d0dd..f153116bc5399b 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -840,8 +840,7 @@ ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
 			ret = -EINVAL;
 			goto out;
 		}
-		if (type >= 0
-		    && unlikely(!access_ok(buf, len))) {
+		if (type != CHECK_IOVEC_ONLY && unlikely(!access_ok(buf, len))) {
 			ret = -EFAULT;
 			goto out;
 		}
@@ -911,7 +910,7 @@ ssize_t compat_rw_copy_check_uvector(int type,
 		}
 		if (len < 0)	/* size_t not fitting in compat_ssize_t .. */
 			goto out;
-		if (type >= 0 &&
+		if (type != CHECK_IOVEC_ONLY &&
 		    !access_ok(compat_ptr(buf), len)) {
 			ret = -EFAULT;
 			goto out;
-- 
2.28.0



More information about the Linux-security-module-archive mailing list