This is a note to let you know that I've just added the patch titled
udf: Check component length before reading it
to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
udf-check-component-length-before-reading-it.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e237ec37ec154564f8690c5bd1795339955eeef9 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@xxxxxxx>
Date: Fri, 19 Dec 2014 14:27:55 +0100
Subject: udf: Check component length before reading it
From: Jan Kara <jack@xxxxxxx>
commit e237ec37ec154564f8690c5bd1795339955eeef9 upstream.
Check that length specified in a component of a symlink fits in the
input buffer we are reading. Also properly ignore component length for
component types that do not use it. Otherwise we read memory after end
of buffer for corrupted udf image.
Reported-by: Carl Henrik Lunde <chlunde@xxxxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/udf/symlink.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
--- a/fs/udf/symlink.c
+++ b/fs/udf/symlink.c
@@ -42,14 +42,17 @@ static int udf_pc_to_char(struct super_b
tolen--;
while (elen < fromlen) {
pc = (struct pathComponent *)(from + elen);
+ elen += sizeof(struct pathComponent);
switch (pc->componentType) {
case 1:
/*
* Symlink points to some place which should be agreed
* upon between originator and receiver of the media. Ignore.
*/
- if (pc->lengthComponentIdent > 0)
+ if (pc->lengthComponentIdent > 0) {
+ elen += pc->lengthComponentIdent;
break;
+ }
/* Fall through */
case 2:
if (tolen == 0)
@@ -74,6 +77,9 @@ static int udf_pc_to_char(struct super_b
/* that would be . - just ignore */
break;
case 5:
+ elen += pc->lengthComponentIdent;
+ if (elen > fromlen)
+ return -EIO;
comp_len = udf_get_filename(sb, pc->componentIdent,
pc->lengthComponentIdent,
p, tolen);
@@ -85,7 +91,6 @@ static int udf_pc_to_char(struct super_b
tolen--;
break;
}
- elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;
}
if (p > to + 1)
p[-1] = '\0';
Patches currently in stable-queue which might be from jack@xxxxxxx are
queue-3.18/isofs-fix-infinite-looping-over-ce-entries.patch
queue-3.18/ncpfs-return-proper-error-from-ncp_ioc_setroot-ioctl.patch
queue-3.18/udf-verify-i_size-when-loading-inode.patch
queue-3.18/udf-check-component-length-before-reading-it.patch
queue-3.18/f2fs-avoid-returning-uninitialized-value-to-userspace-from-f2fs_trim_fs.patch
queue-3.18/udf-verify-symlink-size-before-loading-it.patch
queue-3.18/isofs-fix-unchecked-printing-of-er-records.patch
queue-3.18/f2fs-fix-possible-data-corruption-in-f2fs_write_begin.patch
queue-3.18/udf-check-path-length-when-reading-symlink.patch
--
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