[Bug 264468] libc: fix possible integer underflow
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Date: Mon, 06 Jun 2022 13:22:46 UTC
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=264468 Mark Johnston <markj@FreeBSD.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|New |Open CC| |markj@FreeBSD.org --- Comment #1 from Mark Johnston <markj@FreeBSD.org> --- In all three cases, orig_buf_size and buffer_size are unsigned. So in the comparison "orig_buf_size < buffer_size - sizeof(struct protoent) - sizeof(char *)", if underflow occurs, the right-hand side will wrap around to a large value and the comparison will evaluate to true, causing __proto_unmarshal_func() to return an error. Also note that "buffer_size" is directly set by the caller, the generic NSS cache code starts the buffer size at NSS_CACHE_BUFFER_INITIAL_SIZE (1KB) and grows it. So, I don't quite see the problem here - can you explain further? BTW, the attached patch does not seem to compile. -- You are receiving this mail because: You are the assignee for the bug.