ffmpeg | branch: master | Tobias Stoeckmann <tob...@stoeckmann.org> | Fri Jan 6 23:33:16 2017 +0100| [95d9a85ca3e662388d5fa7ef1937d1c3fbe2dcd5] | committer: Michael Niedermayer
ffserver: local OOB write with custom program name When the command line for children is created, it is assumed that my_program_name always ends with "ffserver", which doesn't have to be true if ffserver is called through a symbolic link. In such a case, it could be that not enough space for "ffmpeg" is available at the end, leading to a buffer overflow. One example would be: $ ln -s /usr/bin/ffserver ~/f; ~/f As this is only a local buffer overflow, i.e. is based on a weird program call, this has NO security impact. Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=95d9a85ca3e662388d5fa7ef1937d1c3fbe2dcd5 --- ffserver.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/ffserver.c b/ffserver.c index 02a5834..8b819b6 100644 --- a/ffserver.c +++ b/ffserver.c @@ -495,20 +495,22 @@ static void start_children(FFServerStream *feed) return; } - pathname = av_strdup (my_program_name); + slash = strrchr(my_program_name, '/'); + if (!slash) { + pathname = av_mallocz(sizeof("ffmpeg")); + } else { + pathname = av_mallocz(slash - my_program_name + sizeof("ffmpeg")); + if (pathname != NULL) { + memcpy(pathname, my_program_name, slash - my_program_name); + } + } if (!pathname) { http_log("Could not allocate memory for children cmd line\n"); return; } - /* replace "ffserver" with "ffmpeg" in the path of current - * program. Ignore user provided path */ + /* use "ffmpeg" in the path of current program. Ignore user provided path */ - slash = strrchr(pathname, '/'); - if (!slash) - slash = pathname; - else - slash++; - strcpy(slash, "ffmpeg"); + strcat(pathname, "ffmpeg"); for (; feed; feed = feed->next) { _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
