linux-kernel - [PATCH] initrd: Fix lz4 decompress with initrd

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <1403317809-4036-1-git-send-email-yinghai@kernel.org>
Date:	Fri, 20 Jun 2014 19:30:09 -0700
From:	Yinghai Lu <yinghai@...nel.org>
To:	Andrew Morton <akpm@...ux-foundation.org>,
	"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...e.hu>
Cc:	Kyungsik Lee <kyungsik.lee@....com>,
	Jan Beulich <JBeulich@...e.com>, linux-kernel@...r.kernel.org,
	Yinghai Lu <yinghai@...nel.org>
Subject: [PATCH] initrd: Fix lz4 decompress with initrd

During testing initrd (>2G) support, find decompress/lz4 does
not work with initrd at all.

decompress_* should support:
1. inbuf[]/outbuf[] for kernel preboot.
2. inbuf[]/flush() for initramfs
3. fill()/flush() for initrd.

in the unlz4 does not handle case 3, as input len is passed
as 0, and it failed in first try.

Fix that add one extra if (fill) checking, and get out if
EOF from the fill().

Signed-off-by: Yinghai Lu <yinghai@...nel.org>

---
 lib/decompress_unlz4.c |   65 ++++++++++++++++++++++++++++++++-----------------
 1 file changed, 43 insertions(+), 22 deletions(-)

Index: linux-2.6/lib/decompress_unlz4.c
===================================================================
--- linux-2.6.orig/lib/decompress_unlz4.c
+++ linux-2.6/lib/decompress_unlz4.c
@@ -83,13 +83,20 @@ STATIC inline int INIT unlz4(u8 *input,
 	if (posp)
 		*posp = 0;
 
-	if (fill)
-		fill(inp, 4);
+	if (fill) {
+		size = fill(inp, 4);
+		if (size < 4) {
+			error("data corrupted");
+			goto exit_2;
+		}
+	}
 
 	chunksize = get_unaligned_le32(inp);
 	if (chunksize == ARCHIVE_MAGICNUMBER) {
-		inp += 4;
-		size -= 4;
+		if (!fill) {
+			inp += 4;
+			size -= 4;
+		}
 	} else {
 		error("invalid header");
 		goto exit_2;
@@ -100,29 +107,44 @@ STATIC inline int INIT unlz4(u8 *input,
 
 	for (;;) {
 
-		if (fill)
-			fill(inp, 4);
+		if (fill) {
+			size = fill(inp, 4);
+			if (size == 0)
+				break;
+			if (size < 4) {
+				error("data corrupted");
+				goto exit_2;
+			}
+		}
 
 		chunksize = get_unaligned_le32(inp);
 		if (chunksize == ARCHIVE_MAGICNUMBER) {
-			inp += 4;
-			size -= 4;
+			if (!fill) {
+				inp += 4;
+				size -= 4;
+			}
 			if (posp)
 				*posp += 4;
 			continue;
 		}
-		inp += 4;
-		size -= 4;
+
 
 		if (posp)
 			*posp += 4;
 
-		if (fill) {
+		if (!fill) {
+			inp += 4;
+			size -= 4;
+		} else {
 			if (chunksize > lz4_compressbound(uncomp_chunksize)) {
 				error("chunk length is longer than allocated");
 				goto exit_2;
 			}
-			fill(inp, chunksize);
+			size = fill(inp, chunksize);
+			if (size < chunksize) {
+				error("data corrupted");
+				goto exit_2;
+			}
 		}
 #ifdef PREBOOT
 		if (out_len >= uncomp_chunksize) {
@@ -149,18 +171,17 @@ STATIC inline int INIT unlz4(u8 *input,
 		if (posp)
 			*posp += chunksize;
 
-		size -= chunksize;
+		if (!fill) {
+			size -= chunksize;
 
-		if (size == 0)
-			break;
-		else if (size < 0) {
-			error("data corrupted");
-			goto exit_2;
+			if (size == 0)
+				break;
+			else if (size < 0) {
+				error("data corrupted");
+				goto exit_2;
+			}
+			inp += chunksize;
 		}
-
-		inp += chunksize;
-		if (fill)
-			inp = inp_start;
 	}
 
 	ret = 0;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/