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55 lines
1.9 KiB
55 lines
1.9 KiB
From 8312eaa576014cd9b965012af51bc1f967b12423 Mon Sep 17 00:00:00 2001
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From: Daniel Axtens <dja@axtens.net>
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Date: Tue, 1 Jan 2019 17:10:49 +1100
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Subject: [PATCH] iso9660: Fail when expected Rockridge extensions is missing
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A corrupted or malicious ISO9660 image can cause read_CE() to loop
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forever.
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read_CE() calls parse_rockridge(), expecting a Rockridge extension
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to be read. However, parse_rockridge() is structured as a while
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loop starting with a sanity check, and if the sanity check fails
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before the loop has run, the function returns ARCHIVE_OK without
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advancing the position in the file. This causes read_CE() to retry
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indefinitely.
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Make parse_rockridge() return ARCHIVE_WARN if it didn't read an
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extension. As someone with no real knowledge of the format, this
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seems more apt than ARCHIVE_FATAL, but both the call-sites escalate
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it to a fatal error immediately anyway.
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Found with a combination of AFL, afl-rb (FairFuzz) and qsym.
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---
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libarchive/archive_read_support_format_iso9660.c | 11 ++++++++++-
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1 file changed, 10 insertions(+), 1 deletion(-)
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diff --git a/libarchive/archive_read_support_format_iso9660.c b/libarchive/archive_read_support_format_iso9660.c
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index 28acfefbb..bad8f1dfe 100644
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--- a/libarchive/archive_read_support_format_iso9660.c
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+++ b/libarchive/archive_read_support_format_iso9660.c
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@@ -2102,6 +2102,7 @@ parse_rockridge(struct archive_read *a, struct file_info *file,
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const unsigned char *p, const unsigned char *end)
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{
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struct iso9660 *iso9660;
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+ int entry_seen = 0;
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iso9660 = (struct iso9660 *)(a->format->data);
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@@ -2257,8 +2258,16 @@ parse_rockridge(struct archive_read *a, struct file_info *file,
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}
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p += p[2];
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+ entry_seen = 1;
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+ }
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+
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+ if (entry_seen)
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+ return (ARCHIVE_OK);
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+ else {
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+ archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
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+ "Tried to parse Rockridge extensions, but none found");
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+ return (ARCHIVE_WARN);
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}
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- return (ARCHIVE_OK);
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}
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static int
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