From 5540f9c430f65631887d31fa26dfdfa576c1c17e Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sun, 22 Mar 2026 18:06:48 -0400 Subject: [PATCH] Fix finalization of decompressor astreamers. Send the correct amount of data to the next astreamer, not the whole allocated buffer size. This bug escaped detection because in present uses the next astreamer is always a tar-file parser which is insensitive to trailing garbage. But that may not be true in future uses. Author: Andrew Dunstan Reviewed-by: Tom Lane Discussion: https://postgr.es/m/2178517.1774064942@sss.pgh.pa.us Backpatch-through: 15 --- src/bin/pg_basebackup/bbstreamer_gzip.c | 9 +++++---- src/bin/pg_basebackup/bbstreamer_lz4.c | 9 +++++---- src/bin/pg_basebackup/bbstreamer_zstd.c | 2 +- 3 files changed, 11 insertions(+), 9 deletions(-) diff --git a/src/bin/pg_basebackup/bbstreamer_gzip.c b/src/bin/pg_basebackup/bbstreamer_gzip.c index 4bfb9e77b9b..40caf8f94cb 100644 --- a/src/bin/pg_basebackup/bbstreamer_gzip.c +++ b/src/bin/pg_basebackup/bbstreamer_gzip.c @@ -323,10 +323,11 @@ bbstreamer_gzip_decompressor_finalize(bbstreamer *streamer) * End of the stream, if there is some pending data in output buffers then * we must forward it to next streamer. */ - bbstreamer_content(mystreamer->base.bbs_next, NULL, - mystreamer->base.bbs_buffer.data, - mystreamer->base.bbs_buffer.maxlen, - BBSTREAMER_UNKNOWN); + if (mystreamer->bytes_written > 0) + bbstreamer_content(mystreamer->base.bbs_next, NULL, + mystreamer->base.bbs_buffer.data, + mystreamer->bytes_written, + BBSTREAMER_UNKNOWN); bbstreamer_finalize(mystreamer->base.bbs_next); } diff --git a/src/bin/pg_basebackup/bbstreamer_lz4.c b/src/bin/pg_basebackup/bbstreamer_lz4.c index 043bbb0cfe1..a914bfa5c1e 100644 --- a/src/bin/pg_basebackup/bbstreamer_lz4.c +++ b/src/bin/pg_basebackup/bbstreamer_lz4.c @@ -395,10 +395,11 @@ bbstreamer_lz4_decompressor_finalize(bbstreamer *streamer) * End of the stream, if there is some pending data in output buffers then * we must forward it to next streamer. */ - bbstreamer_content(mystreamer->base.bbs_next, NULL, - mystreamer->base.bbs_buffer.data, - mystreamer->base.bbs_buffer.maxlen, - BBSTREAMER_UNKNOWN); + if (mystreamer->bytes_written > 0) + bbstreamer_content(mystreamer->base.bbs_next, NULL, + mystreamer->base.bbs_buffer.data, + mystreamer->bytes_written, + BBSTREAMER_UNKNOWN); bbstreamer_finalize(mystreamer->base.bbs_next); } diff --git a/src/bin/pg_basebackup/bbstreamer_zstd.c b/src/bin/pg_basebackup/bbstreamer_zstd.c index 02f5db77c2d..1671e03699a 100644 --- a/src/bin/pg_basebackup/bbstreamer_zstd.c +++ b/src/bin/pg_basebackup/bbstreamer_zstd.c @@ -333,7 +333,7 @@ bbstreamer_zstd_decompressor_finalize(bbstreamer *streamer) if (mystreamer->zstd_outBuf.pos > 0) bbstreamer_content(mystreamer->base.bbs_next, NULL, mystreamer->base.bbs_buffer.data, - mystreamer->base.bbs_buffer.maxlen, + mystreamer->zstd_outBuf.pos, BBSTREAMER_UNKNOWN); bbstreamer_finalize(mystreamer->base.bbs_next);