commit fa33cdbf3eceb0206a4f844fe91aeebcf6ff2b7a upstream.
In some cases, using the 'truncate' command to extend a UDF file results
in a mismatch between the length of the file's extents (specifically, due
to incorrect length of the final NOT_ALLOCATED extent) and the information
(file) length. The discrepancy can prevent other operating systems
(i.e., Windows 10) from opening the file.
Two particular errors have been observed when extending a file:
1. The final extent is larger than it should be, having been rounded up
to a multiple of the block size.
B. The final extent is not shorter than it should be, due to not having
been updated when the file's information length was increased.
[JK: simplified udf_do_extend_final_block(), fixed up some types]
Fixes: 2c948b3f86e5 ("udf: Avoid IO in udf_clear_inode")
CC: stable@vger.kernel.org
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Link: https://lore.kernel.org/r/1561948775-5878-1-git-send-email-steve@digidescorp.com
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
c4ba3f2f09