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Null-terminate the output buffer of LZ4Stream_gets

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LZ4Stream_gets did not null-terminate its output buffer. The callers expected
the buffer to be null-terminated and passed it around to functions such as
sscanf with unintended consequences.

Author: Georgios Kokolatos <gkokolatos@pm.me>
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/94ae9bca-5ebb-1e68-bb7b-4f32e89fefbe@gmail.com
This commit is contained in:
Tomas Vondra 2023-05-17 16:35:17 +02:00
parent d8c3106bb6
commit 3c18d90f89
1 changed files with 11 additions and 1 deletions
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12
src/bin/pg_dump/compress_lz4.c
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@ -459,6 +459,10 @@ LZ4Stream_read_internal(LZ4State *state, void *ptr, int ptrsize, bool eol_flag)
if (!LZ4Stream_init(state, size, false /* decompressing */ ))
return -1;
/* No work needs to be done for a zero-sized output buffer */
if (size <= 0)
return 0;
/* Verify that there is enough space in the outbuf */
if (size > state->buflen)
{
@ -636,7 +640,7 @@ LZ4Stream_gets(char *ptr, int size, CompressFileHandle *CFH)
LZ4State *state = (LZ4State *) CFH->private_data;
int ret;
ret = LZ4Stream_read_internal(state, ptr, size, true);
ret = LZ4Stream_read_internal(state, ptr, size - 1, true);
if (ret < 0 || (ret == 0 && !LZ4Stream_eof(CFH)))
pg_fatal("could not read from input file: %s", LZ4Stream_get_error(CFH));
@ -644,6 +648,12 @@ LZ4Stream_gets(char *ptr, int size, CompressFileHandle *CFH)
if (ret == 0)
return NULL;
/*
* Our caller expects the return string to be NULL terminated
* and we know that ret is greater than zero.
*/
ptr[ret - 1] = '\0';
return ptr;
}