pkg/debian: Drop decompress_unlz4 patch

This patch is now upstream.

pkg/debian/kernel/0001-lib-decompress_unlz4.c-correctly-handle-zero-padding.patch

@@ -1,85 +0,0 @@
-From 6d056d620ff6a61c84269f0cf71003829ffecd6a Mon Sep 17 00:00:00 2001
-From: Dimitri John Ledkov <xnox@ubuntu.com>
-Date: Thu, 14 Jan 2021 20:02:56 +0000
-Subject: [PATCH] lib/decompress_unlz4.c: correctly handle zero-padding around
- initrds.
-
-lz4 compatible decompressor is simple. The format is underspecified and
-relies on EOF notification to determine when to stop. Initramfs buffer
-format[1] explicitly states that it can have arbitrary number of zero
-padding. Thus when operating without a fill function, be extra careful to
-ensure that sizes less than 4, or apperantly empty chunksizes are treated
-as EOF.
-
-To test this I have created two cpio initrds, first a normal one,
-main.cpio. And second one with just a single /test-file with content
-"second" second.cpio. Then i compressed both of them with gzip, and with
-lz4 -l. Then I created a padding of 4 bytes (dd if=/dev/zero of=pad4 bs=1
-count=4). To create four testcase initrds:
-
- 1) main.cpio.gzip + extra.cpio.gzip = pad0.gzip
- 2) main.cpio.lz4  + extra.cpio.lz4 = pad0.lz4
- 3) main.cpio.gzip + pad4 + extra.cpio.gzip = pad4.gzip
- 4) main.cpio.lz4  + pad4 + extra.cpio.lz4 = pad4.lz4
-
-The pad4 test-cases replicate the initrd load by grub, as it pads and
-aligns every initrd it loads.
-
-All of the above boot, however /test-file was not accessible in the initrd
-for the testcase #4, as decoding in lz4 decompressor failed. Also an error
-message printed which usually is harmless.
-
-Whith a patched kernel, all of the above testcases now pass, and /test-file
-is accessible.
-
-This fixes lz4 initrd decompress warning on every boot with grub. And more
-importantly this fixes inability to load multiple lz4 compressed initrds
-with grub.
-
-I guess I should convert above decompressor streams with/without padding
-into kunit tests, across all decompressor algorithms.
-
-[1] ./Documentation/driver-api/early-userspace/buffer-format.rst
-
-BugLink: https://bugs.launchpad.net/bugs/1835660
-Signed-off-by: Dimitri John Ledkov <xnox@ubuntu.com>
----
- lib/decompress_unlz4.c | 8 ++++++++
- 1 file changed, 8 insertions(+)
-
-diff --git a/lib/decompress_unlz4.c b/lib/decompress_unlz4.c
-index c0cfcfd486be..e6327391b6b6 100644
---- a/lib/decompress_unlz4.c
-+++ b/lib/decompress_unlz4.c
-@@ -112,6 +112,9 @@ STATIC inline int INIT unlz4(u8 *input, long in_len,
- 				error("data corrupted");
- 				goto exit_2;
- 			}
-+		} else if (size < 4) {
-+			/* empty or end-of-file */
-+			goto exit_3;
- 		}
- 
- 		chunksize = get_unaligned_le32(inp);
-@@ -125,6 +128,10 @@ STATIC inline int INIT unlz4(u8 *input, long in_len,
- 			continue;
- 		}
- 
-+		if (!fill && chunksize == 0) {
-+			/* empty or end-of-file */
-+			goto exit_3;
-+		}
- 
- 		if (posp)
- 			*posp += 4;
-@@ -184,6 +191,7 @@ STATIC inline int INIT unlz4(u8 *input, long in_len,
- 		}
- 	}
- 
-+exit_3:
- 	ret = 0;
- exit_2:
- 	if (!input)
--- 
-2.31.1
-