![Gustavo Zacarias](/assets/img/avatar_default.png)
Fixes: CVE-2016-2037 - The cpio_safer_name_suffix function in util.c in cpio 2.11 allows remote attackers to cause a denial of service (out-of-bounds write) via a crafted cpio file. Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar> Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
52 lines
1.6 KiB
Diff
52 lines
1.6 KiB
Diff
From: Pavel Raiskup
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Subject: [Bug-cpio] [PATCH] fix 1-byte out-of-bounds write
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Date: Tue, 26 Jan 2016 23:17:54 +0100
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Other calls to cpio_safer_name_suffix seem to be safe.
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* src/copyin.c (process_copy_in): Make sure that file_hdr.c_name
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has at least two bytes allocated.
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* src/util.c (cpio_safer_name_suffix): Document that use of this
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function requires to be careful.
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Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
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---
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Patch status: fetched/submitted
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URL: https://lists.gnu.org/archive/html/bug-cpio/2016-01/msg00005.html
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src/copyin.c | 2 ++
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src/util.c | 5 ++++-
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2 files changed, 6 insertions(+), 1 deletion(-)
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diff --git a/src/copyin.c b/src/copyin.c
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index cde911e..032d35f 100644
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--- a/src/copyin.c
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+++ b/src/copyin.c
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@@ -1385,6 +1385,8 @@ process_copy_in ()
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break;
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}
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+ if (file_hdr.c_namesize <= 1)
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+ file_hdr.c_name = xrealloc(file_hdr.c_name, 2);
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cpio_safer_name_suffix (file_hdr.c_name, false, !no_abs_paths_flag,
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false);
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diff --git a/src/util.c b/src/util.c
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index 6ff6032..2763ac1 100644
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--- a/src/util.c
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+++ b/src/util.c
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@@ -1411,7 +1411,10 @@ set_file_times (int fd,
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}
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/* Do we have to ignore absolute paths, and if so, does the filename
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- have an absolute path? */
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+ have an absolute path?
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+ Before calling this function make sure that the allocated NAME buffer has
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+ capacity at least 2 bytes to allow us to store the "." string inside. */
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+
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void
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cpio_safer_name_suffix (char *name, bool link_target, bool absolute_names,
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bool strip_leading_dots)
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--
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2.5.0
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