# [PATCH] Add overflow check to get_delta_hdr_size 3 messages from 2017-08-12 to 2017-08-14. Participants: Martin Koegler, Junio C Hamano. Thread: https://gitlist.dev/t/46574 ## Martin Koegler, 2017-08-12 07:27 Subject: [PATCH] Add overflow check to get_delta_hdr_size Message-ID: <1502522838-12581-1-git-send-email-martin@mail.zuhause> URL: https://gitlist.dev/e/1502522838-12581-1-git-send-email-martin%40mail.zuhause ``` From: Martin Koegler Signed-off-by: Martin Koegler --- Applies on top of my size_t series I'm not sure, if die or error is better. delta.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/delta.h b/delta.h index 2df0f55..18a4983 100644 --- a/delta.h +++ b/delta.h @@ -96,6 +96,11 @@ static inline size_t get_delta_hdr_size(const unsigned char **datap, cmd = *data++; size |= (cmd & 0x7f) << i; i += 7; + if (bitsizeof(size_t) <= i) { + error("too large object size"); + size = 0; + break; + } } while (cmd & 0x80 && data < top); *datap = data; return size; -- 2.1.4 ``` ## Junio C Hamano, 2017-08-14 16:55 Subject: Re: [PATCH] Add overflow check to get_delta_hdr_size Message-ID: URL: https://gitlist.dev/e/xmqqlgmmw0lc.fsf%40gitster.mtv.corp.google.com In-Reply-To: <1502522838-12581-1-git-send-email-martin@mail.zuhause> ``` Martin Koegler writes: > From: Martin Koegler > > Signed-off-by: Martin Koegler > --- > Applies on top of my size_t series > > I'm not sure, if die or error is better. As there is no fallback when we hit it, die would be sufficient; the only thing the callers of this helper, or their callers, could do is as a reaction to an error return from here would be to die themselves, I would think. > > delta.h | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/delta.h b/delta.h > index 2df0f55..18a4983 100644 > --- a/delta.h > +++ b/delta.h > @@ -96,6 +96,11 @@ static inline size_t get_delta_hdr_size(const unsigned char **datap, > cmd = *data++; > size |= (cmd & 0x7f) << i; > i += 7; > + if (bitsizeof(size_t) <= i) { > + error("too large object size"); > + size = 0; > + break; > + } > } while (cmd & 0x80 && data < top); > *datap = data; > return size; ``` ## Junio C Hamano, 2017-08-14 16:56 Subject: Re: [PATCH] Add overflow check to get_delta_hdr_size Message-ID: URL: https://gitlist.dev/e/xmqqk226w0kf.fsf%40gitster.mtv.corp.google.com In-Reply-To: <1502522838-12581-1-git-send-email-martin@mail.zuhause> ``` Martin Koegler writes: > From: Martin Koegler > > Signed-off-by: Martin Koegler > --- > Applies on top of my size_t series > > I'm not sure, if die or error is better. As there is no fallback when we hit it, die would be sufficient; the only thing the callers of this helper, or their callers, could do is as a reaction to an error return from here would be to die themselves, I would think. > delta.h | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/delta.h b/delta.h > index 2df0f55..18a4983 100644 > --- a/delta.h > +++ b/delta.h > @@ -96,6 +96,11 @@ static inline size_t get_delta_hdr_size(const unsigned char **datap, > cmd = *data++; > size |= (cmd & 0x7f) << i; > i += 7; > + if (bitsizeof(size_t) <= i) { > + error("too large object size"); > + size = 0; > + break; > + } > } while (cmd & 0x80 && data < top); > *datap = data; > return size; ```