This is a note to let you know that I've just added the patch titled
udf: Verify symlink size before loading it
to the 3.17-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-verify-symlink-size-before-loading-it.patch
and it can be found in the queue-3.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a1d47b262952a45aae62bd49cfaf33dd76c11a2c Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@xxxxxxx>
Date: Fri, 19 Dec 2014 12:21:47 +0100
Subject: udf: Verify symlink size before loading it
From: Jan Kara <jack@xxxxxxx>
commit a1d47b262952a45aae62bd49cfaf33dd76c11a2c upstream.
UDF specification allows arbitrarily large symlinks. However we support
only symlinks at most one block large. Check the length of the symlink
so that we don't access memory beyond end of the symlink block.
Reported-by: Carl Henrik Lunde <chlunde@xxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/udf/symlink.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
--- a/fs/udf/symlink.c
+++ b/fs/udf/symlink.c
@@ -99,11 +99,17 @@ static int udf_symlink_filler(struct fil
struct inode *inode = page->mapping->host;
struct buffer_head *bh = NULL;
unsigned char *symlink;
- int err = -EIO;
+ int err;
unsigned char *p = kmap(page);
struct udf_inode_info *iinfo;
uint32_t pos;
+ /* We don't support symlinks longer than one block */
+ if (inode->i_size > inode->i_sb->s_blocksize) {
+ err = -ENAMETOOLONG;
+ goto out_unmap;
+ }
+
iinfo = UDF_I(inode);
pos = udf_block_map(inode, 0);
@@ -113,8 +119,10 @@ static int udf_symlink_filler(struct fil
} else {
bh = sb_bread(inode->i_sb, pos);
- if (!bh)
- goto out;
+ if (!bh) {
+ err = -EIO;
+ goto out_unlock_inode;
+ }
symlink = bh->b_data;
}
@@ -130,9 +138,10 @@ static int udf_symlink_filler(struct fil
unlock_page(page);
return 0;
-out:
+out_unlock_inode:
up_read(&iinfo->i_data_sem);
SetPageError(page);
+out_unmap:
kunmap(page);
unlock_page(page);
return err;
Patches currently in stable-queue which might be from jack@xxxxxxx are
queue-3.17/isofs-fix-infinite-looping-over-ce-entries.patch
queue-3.17/ncpfs-return-proper-error-from-ncp_ioc_setroot-ioctl.patch
queue-3.17/udf-verify-i_size-when-loading-inode.patch
queue-3.17/udf-check-component-length-before-reading-it.patch
queue-3.17/udf-verify-symlink-size-before-loading-it.patch
queue-3.17/isofs-fix-unchecked-printing-of-er-records.patch
queue-3.17/f2fs-fix-possible-data-corruption-in-f2fs_write_begin.patch
queue-3.17/udf-check-path-length-when-reading-symlink.patch
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