Messages in this thread Patch in this message | | | From | Ninad Palsule <> | Subject | [PATCH v3 2/2] fsi: sbefifo: Handle pending write command | Date | Tue, 10 Oct 2023 15:43:48 -0500 |
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If previous write command is still pending then free it first.
As per the current kernel driver design, write operation prepares a buffer for FSI write, the actual FSI write is performed on next read operation. There is a possibility of memory leak if buggy application sends two back to back writes or two parallel writes.
Signed-off-by: Ninad Palsule <ninad@linux.ibm.com> --- v3: - Incorporated review comments by Eddie. --- drivers/fsi/fsi-sbefifo.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/fsi/fsi-sbefifo.c b/drivers/fsi/fsi-sbefifo.c index a95b32461f8f3..1cc88a78e588a 100644 --- a/drivers/fsi/fsi-sbefifo.c +++ b/drivers/fsi/fsi-sbefifo.c @@ -877,6 +877,13 @@ static ssize_t sbefifo_user_write(struct file *file, const char __user *buf, mutex_lock(&user->file_lock); + /* If previous write command is still pending then free it. It is safe + * to do that because read cannot be in progress since we hold the + * lock. + */ + if (user->pending_cmd) + sbefifo_release_command(user); + /* Can we use the pre-allocate buffer ? If not, allocate */ if (len <= PAGE_SIZE) user->pending_cmd = user->cmd_page; -- 2.39.2
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