From 6ccfc44922123d497501a491b8becfca7b0096bb 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 698c9009ba1..d0fa38610c1 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 b86058b1243..8a92be0d19c 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 6bccbf59d6f..68af87eb3bf 100644 --- a/src/bin/pg_basebackup/bbstreamer_zstd.c +++ b/src/bin/pg_basebackup/bbstreamer_zstd.c @@ -343,7 +343,7 @@ 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);