diff mbox series

[05/14] fs: check FMODE_WRITE in __kernel_write

Message ID 20200513065656.2110441-6-hch@lst.de (mailing list archive)
State New, archived
Headers show
Series [01/14] cachefiles: switch to kernel_write | expand

Commit Message

Christoph Hellwig May 13, 2020, 6:56 a.m. UTC 
We still need to check if the fѕ is open write, even for the low-level
helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/read_write.c | 2 ++
 1 file changed, 2 insertions(+)
diff mbox series

Patch

diff --git a/fs/read_write.c b/fs/read_write.c
index 2c601d853ff3d..76be155ad9824 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -505,6 +505,8 @@  ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t
 	const char __user *p;
 	ssize_t ret;
 
+	if (!(file->f_mode & FMODE_WRITE))
+		return -EBADF;
 	if (!(file->f_mode & FMODE_CAN_WRITE))
 		return -EINVAL;