The patch titled
Subject: kexec_file: increase maximum file size to 4G
has been added to the -mm mm-nonmm-unstable branch. Its filename is
kexec_file-increase-maximum-file-size-to-4g.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kexec_file-increase-maximum-file-size-to-4g.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Subject: kexec_file: increase maximum file size to 4G
Date: Fri, 27 May 2022 02:55:35 +0000
In some case initrd can be large. For example, it could be a netboot
image loaded by u-root, that is kexec'ing into it.
The maximum size of initrd is arbitrary set to 2G. Also, the limit is not
very obvious because it is hidden behind a generic INT_MAX macro.
Theoretically, we could make it LONG_MAX, but it is safer to keep it sane,
and just increase it to 4G.
Increase the size to 4G, and make it obvious by having a new macro that
specifies the maximum file size supported by kexec_file_load() syscall:
KEXEC_FILE_SIZE_MAX.
Link: https://lkml.kernel.org/r/20220527025535.3953665-3-pasha.tatashin@xxxxxxxxxx
Signed-off-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Sasha Levin <sashal@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Greg Thelen <gthelen@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/kexec_file.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
--- a/kernel/kexec_file.c~kexec_file-increase-maximum-file-size-to-4g
+++ a/kernel/kexec_file.c
@@ -31,6 +31,9 @@
static int kexec_calculate_store_digests(struct kimage *image);
+/* Maximum size in bytes for kernel/initrd files. */
+#define KEXEC_FILE_SIZE_MAX min_t(s64, 4LL << 30, SSIZE_MAX)
+
/*
* Currently this is the only default function that is exported as some
* architectures need it to do additional handlings.
@@ -189,11 +192,12 @@ kimage_file_prepare_segments(struct kima
const char __user *cmdline_ptr,
unsigned long cmdline_len, unsigned flags)
{
- int ret;
+ ssize_t ret;
void *ldata;
ret = kernel_read_file_from_fd(kernel_fd, 0, &image->kernel_buf,
- INT_MAX, NULL, READING_KEXEC_IMAGE);
+ KEXEC_FILE_SIZE_MAX, NULL,
+ READING_KEXEC_IMAGE);
if (ret < 0)
return ret;
image->kernel_buf_len = ret;
@@ -213,7 +217,7 @@ kimage_file_prepare_segments(struct kima
/* It is possible that there no initramfs is being loaded */
if (!(flags & KEXEC_FILE_NO_INITRAMFS)) {
ret = kernel_read_file_from_fd(initrd_fd, 0, &image->initrd_buf,
- INT_MAX, NULL,
+ KEXEC_FILE_SIZE_MAX, NULL,
READING_KEXEC_INITRAMFS);
if (ret < 0)
goto out;
_
Patches currently in -mm which might be from pasha.tatashin@xxxxxxxxxx are
fs-kernel_read_file-allow-to-read-files-up-to-ssize_t.patch
kexec_file-increase-maximum-file-size-to-4g.patch
