This is a note to let you know that I've just added the patch titled um: fix error return code in winch_tramp() to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: um-fix-error-return-code-in-winch_tramp.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 3a2da33161d5ce6f6464946739d2de6838b30ae0 Author: Zhen Lei <thunder.leizhen@xxxxxxxxxx> Date: Sat May 8 11:22:39 2021 +0800 um: fix error return code in winch_tramp() [ Upstream commit ccf1236ecac476d9d2704866d9a476c86e387971 ] Fix to return a negative error code from the error handling case instead of 0, as done elsewhere in this function. Fixes: 89df6bfc0405 ("uml: DEBUG_SHIRQ fixes") Reported-by: Hulk Robot <hulkci@xxxxxxxxxx> Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx> Acked-By: anton.ivanov@xxxxxxxxxxxxxxxxxx Signed-off-by: Richard Weinberger <richard@xxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c index d8845d4aac6a..6040817c036f 100644 --- a/arch/um/drivers/chan_user.c +++ b/arch/um/drivers/chan_user.c @@ -256,7 +256,8 @@ static int winch_tramp(int fd, struct tty_port *port, int *fd_out, goto out_close; } - if (os_set_fd_block(*fd_out, 0)) { + err = os_set_fd_block(*fd_out, 0); + if (err) { printk(UM_KERN_ERR "winch_tramp: failed to set thread_fd " "non-blocking.\n"); goto out_close;