# [PATCH] Don't use memcpy when source and dest. buffers may overlap 1 messages from 2006-12-11 to 2006-12-11. Participants: Jim Meyering. Thread: https://gitlist.dev/t/43759 ## Jim Meyering, 2006-12-11 18:06 Subject: [PATCH] Don't use memcpy when source and dest. buffers may overlap Message-ID: <87slfm489h.fsf@rho.meyering.net> URL: https://gitlist.dev/e/87slfm489h.fsf%40rho.meyering.net ``` git-index-pack can call memcpy with overlapping source and destination buffers. The patch below makes it use memmove instead. If you want to demonstrate a failure, add the following two lines + if (input_offset < input_len) + abort (); before the existing memcpy call (shown in the patch below), and then run this: (cd t; sh ./t5500-fetch-pack.sh) Signed-off-by: Jim Meyering --- index-pack.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/index-pack.c b/index-pack.c index 8331d99..6d6c92b 100644 --- a/index-pack.c +++ b/index-pack.c @@ -96,7 +96,7 @@ static void flush(void) if (output_fd >= 0) write_or_die(output_fd, input_buffer, input_offset); SHA1_Update(&input_ctx, input_buffer, input_offset); - memcpy(input_buffer, input_buffer + input_offset, input_len); + memmove(input_buffer, input_buffer + input_offset, input_len); input_offset = 0; } } -- ```