[PATCH 02/11] fs: check FMODE_WRITE in __kernel_write

From: Christoph Hellwig
Date: Fri May 08 2020 - 05:22:32 EST


We still need to check if the fÑ is open write, even for the low-level
helper.

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

diff --git a/fs/read_write.c b/fs/read_write.c
index d5aaf3a4198b9..d5c754080e5a5 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;

--
2.26.2