diff options
| author | Mikhail Zaslonko <zaslonko@linux.ibm.com> | 2023-02-21 14:16:17 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-02-27 17:00:14 -0800 |
| commit | 1c0a0af511effbd75beffa6c5e54fd64d3563860 (patch) | |
| tree | 20d214538385d9ff2e48acc748b963af3b6c1227 /lib/zlib_deflate | |
| parent | 3f98c9a62c338bbe06a215c9491e6166ea39bf82 (diff) | |
lib/zlib: DFLTCC deflate does not write all available bits for Z_NO_FLUSH
DFLTCC deflate with Z_NO_FLUSH might generate a corrupted stream when the
output buffer is not large enough to fit all the deflate output at once.
The problem takes place on closing the deflate block since flush_pending()
might leave some output bits not written. Similar problem for software
deflate with Z_BLOCK flush option (not supported by kernel zlib deflate)
has been fixed a while ago in userspace zlib but the fix never got to the
kernel.
Now flush_pending() flushes the bit buffer before copying out the byte
buffer, in order to really flush as much as possible.
Currently there are no users of DFLTCC deflate with Z_NO_FLUSH option in
the kernel so the problem remained hidden for a while.
This commit is based on the old zlib commit:
https://github.com/madler/zlib/commit/0b828b4
Link: https://lkml.kernel.org/r/20230221131617.3369978-2-zaslonko@linux.ibm.com
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib/zlib_deflate')
| -rw-r--r-- | lib/zlib_deflate/defutil.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/lib/zlib_deflate/defutil.h b/lib/zlib_deflate/defutil.h index 385333b22ec6..4ea40f5a279f 100644 --- a/lib/zlib_deflate/defutil.h +++ b/lib/zlib_deflate/defutil.h @@ -420,9 +420,11 @@ static inline void flush_pending( z_streamp strm ) { + unsigned len; deflate_state *s = (deflate_state *) strm->state; - unsigned len = s->pending; + bi_flush(s); + len = s->pending; if (len > strm->avail_out) len = strm->avail_out; if (len == 0) return; |