Commit 4353f033 authored May 28, 2020 by Tony Luck Committed by Ard Biesheuvel Jun 15, 2020

efivarfs: Don't return -EINTR when rate-limiting reads



Applications that read EFI variables may see a return
value of -EINTR if they exceed the rate limit and a
signal delivery is attempted while the process is sleeping.

This is quite surprising to the application, which probably
doesn't have code to handle it.

Change the interruptible sleep to a non-interruptible one.

Reported-by: Lennart Poettering <mzxreary@0pointer.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20200528194905.690-3-tony.luck@intel.com


Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

parent 2096721f

fs/efivarfs/file.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -73,10 +73,8 @@ static ssize_t efivarfs_file_read(struct file file, char __user userbuf,
		ssize_t size = 0;
		int err;

		while (!__ratelimit(&file->f_cred->user->ratelimit)) {
		if (!msleep_interruptible(50))
		return -EINTR;
		}
		while (!__ratelimit(&file->f_cred->user->ratelimit))
		msleep(50);

		err = efivar_entry_size(var, &datasize);

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