Fix possible UDF deadlock and memory corruption (CVE-2006-4145)
UDF code is not really ready to handle extents larger that 1GB. This is
the easy way to forbid creating those.
Also truncation code did not count with the case when there are no
extents in the file and we are extending the file.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/fs/udf/truncate.c b/fs/udf/truncate.c
index e1b0e8c..0abd66c 100644
--- a/fs/udf/truncate.c
+++ b/fs/udf/truncate.c
@@ -239,38 +239,52 @@
{
if (offset)
{
- extoffset -= adsize;
- etype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1);
- if (etype == (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
- {
- extoffset -= adsize;
- elen = EXT_NOT_RECORDED_NOT_ALLOCATED | (elen + offset);
- udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 0);
- }
- else if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
- {
- kernel_lb_addr neloc = { 0, 0 };
- extoffset -= adsize;
- nelen = EXT_NOT_RECORDED_NOT_ALLOCATED |
- ((elen + offset + inode->i_sb->s_blocksize - 1) &
- ~(inode->i_sb->s_blocksize - 1));
- udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 1);
- udf_add_aext(inode, &bloc, &extoffset, eloc, (etype << 30) | elen, &bh, 1);
- }
- else
- {
- if (elen & (inode->i_sb->s_blocksize - 1))
- {
- extoffset -= adsize;
- elen = EXT_RECORDED_ALLOCATED |
- ((elen + inode->i_sb->s_blocksize - 1) &
- ~(inode->i_sb->s_blocksize - 1));
- udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 1);
- }
+ /*
+ * OK, there is not extent covering inode->i_size and
+ * no extent above inode->i_size => truncate is
+ * extending the file by 'offset'.
+ */
+ if ((!bh && extoffset == udf_file_entry_alloc_offset(inode)) ||
+ (bh && extoffset == sizeof(struct allocExtDesc))) {
+ /* File has no extents at all! */
memset(&eloc, 0x00, sizeof(kernel_lb_addr));
elen = EXT_NOT_RECORDED_NOT_ALLOCATED | offset;
udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1);
}
+ else {
+ extoffset -= adsize;
+ etype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1);
+ if (etype == (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
+ {
+ extoffset -= adsize;
+ elen = EXT_NOT_RECORDED_NOT_ALLOCATED | (elen + offset);
+ udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 0);
+ }
+ else if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
+ {
+ kernel_lb_addr neloc = { 0, 0 };
+ extoffset -= adsize;
+ nelen = EXT_NOT_RECORDED_NOT_ALLOCATED |
+ ((elen + offset + inode->i_sb->s_blocksize - 1) &
+ ~(inode->i_sb->s_blocksize - 1));
+ udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 1);
+ udf_add_aext(inode, &bloc, &extoffset, eloc, (etype << 30) | elen, &bh, 1);
+ }
+ else
+ {
+ if (elen & (inode->i_sb->s_blocksize - 1))
+ {
+ extoffset -= adsize;
+ elen = EXT_RECORDED_ALLOCATED |
+ ((elen + inode->i_sb->s_blocksize - 1) &
+ ~(inode->i_sb->s_blocksize - 1));
+ udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 1);
+ }
+ memset(&eloc, 0x00, sizeof(kernel_lb_addr));
+ elen = EXT_NOT_RECORDED_NOT_ALLOCATED | offset;
+ udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1);
+ }
+ }
}
}
UDF_I_LENEXTENTS(inode) = inode->i_size;